401 results on '"*NAPHTHALENE synthesis"'
Search Results
2. Synthesis of Thiophene‐annulated Naphthalene Diimide‐based Small‐Molecular Acceptors via Two‐step C−H Activation.
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Matsidik, Rukiya and Takimiya, Kazuo
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NAPHTHALENE synthesis , *SMALL molecules , *N-type semiconductors , *THIOPHENES , *SUZUKI reaction , *ARYL bromides - Abstract
Thiophene‐annulated naphthalene diimide (NTI)‐based molecules have recently emerged as an important class of n‐type electronic materials. However, their synthesis has predominantly been achieved by Stille or Suzuki coupling reactions despite the presence of a potential C−H bond in NTI. Additionally, the synthesis of NTI or more generally mono‐functionalization of naphthalene diimide (NDI) starts with a cumbersome bromination that results in a low yield, is unselective, and requires tedious purification. We herein thus address these issues via a two‐step C−H activation: a rhodium‐catalyzed direct C−H iodinization is first presented for NDI, followed by establishing an efficient direct arylation protocol for NTI with high yield and robustness. Coupling of up to four NTI units on a benzene or pyrene core is demonstrated along with other aryl bromide substrates. All the herein reported NTI‐based small molecules showed n‐type semiconductor behavior under air. [ABSTRACT FROM AUTHOR] more...
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- 2019
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Catalog
3. Electrochemical [4+2] Annulation‐Rearrangement‐Aromatization of Styrenes: Synthesis of Naphthalene Derivatives.
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Ma, Yueyue, Lv, Jufeng, Liu, Chengyu, Yao, Xiantong, Yan, Guoming, Yu, Wei, and Ye, Jinxing
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NAPHTHALENE synthesis , *STYRENE , *NAPHTHALENE derivatives , *NAPHTHALENE , *ANNULATION , *RING formation (Chemistry) - Abstract
We report the first electrochemical strategy to synthesize functionalized naphthalene derivatives through [4+2] annulation—rearrangement–aromatization from styrenes under mild conditions. The electrolysis does not require metals, oxidants and high valence substrates, indicating the atom and step‐economy ideals. The dehydrodimer produced through [4+2] cycloaddition of 4‐methoxy α‐methyl styrene is isolated and proved to be the key intermediate for the following oxydehydrogenation to form carbon cation, which undergoes rearrangement–aromatization to afford the final products. This reaction represents a powerful access to construct multi‐substituted naphthalene blocks in a single step. [ABSTRACT FROM AUTHOR] more...
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- 2019
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4. A Solid‐State‐Emissive 1,8‐Naphthalimide Probe Based on Photoinduced Electron Transfer and Aggregation‐Induced Emission.
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Georgiev, Nikolai I., Bakov, Ventsislav V., and Bojinov, Vladimir B.
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NAPHTHALIMIDES , *NAPHTHALENE synthesis , *NAPHTHALENE derivatives , *FLUORESCENCE , *PHOTOINDUCED electron transfer , *ELECTRON emission - Abstract
In this work we focused on the design and synthesis of a fluorescence sensing 4‐chloro‐1,8‐naptalimide derivative operating simultaneously by photoinduced electron transfer (PET) and aggregation induced emission (AIE) mechanisms. Absorption and fluorescence properties of the probe were studied as a function of pH in solution and in solid state as compared to the properties of similar 1,8‐naphthalimide derivatives without a substituent at the 1,8‐naphthalimide C‐4 position. The photoinduced fluorescence enhancement of the probe was FE = 22 after protonation in solution (λF = 405 nm, pKa = 8.50±0.08) and FE = 44 (λF = 472 nm) in solid state after reversible exposure on HCl and ammonia vapours due to the amalgamation of monomer emission and AIE. In solid state on paper support the PET process in the probe was switched "off" in a pH window 2.5‐1.5. Due to the remarkable changes in the fluorescence emission the synthesized compound was successfully applied as a solid‐state chemosensing material for rapid detection of acid‐base vapours and pH in aqueous solutions. The concept proposed herein could drive the classic AIE and PET molecular sensors towards new directions and practical applications. [ABSTRACT FROM AUTHOR] more...
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- 2019
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5. Synthesis and evaluation of Naphthalene-1, 8-dithiolate chelating ruthenium carbene catalyst for Z-Stereoretentive olefin metathesis.
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Wang, Tao, Xie, Qingxiao, Guo, Weijie, Wu, Shutao, Zhang, Huiqing, and Wang, Jianhui
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NAPHTHALENE synthesis , *RUTHENIUM catalysts , *ALKENES - Abstract
Abstract A highly Z -stereoretentive olefin metathesis ruthenium carbene catalyst containing a naphthalene-1,8-dithiol ligand was synthesized, and the structure was determined by single-crystal X-ray diffraction. The new ruthenium carbene catalyst could catalyze cross-metathesis reactions of terminal alkenes with (Z)-but-2-ene-1,4-diol to give highly Z -stereoretentive products. Like to other ruthenium carbene catalysts, the new complex tolerates many different functional groups. Graphical abstract Image 1 Highlights • Naphthalene-1,8-dithiolate chelating Ru-carbene catalyst was synthesized. • Single-crystal X-ray diffraction was tested to determine the catalyst. • Catalyst can catalyze CM reactions to give highly Z -stereoretentive products. • The new complex tolerates many different functional groups. [ABSTRACT FROM AUTHOR] more...
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- 2019
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6. Efficient synthetic methodology for the construction of dihydronaphthalene and benzosuberene molecular frameworks.
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Mondal, Deboprosad, Niu, Haichan, and Pinney, Kevin G.
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NAPHTHALENE synthesis , *COUMARINS , *PALLADIUM catalysts , *CHEMICAL reactions , *PHENOLS , *ANILINE - Abstract
Graphical abstract Highlights • Efficient synthetic methodology for benzosuberene and dihydronaphthalene analogues. • Methodology accommodated larger scale reactions. • Palladium catalyzed amination converted phenolic analogues to aniline congeners. Abstract Benzosuberene analogues (1 and 2) and dihydronaphthalene analogues (3 and 4) function as potent inhibitors of tubulin polymerization, demonstrate pronounced cytotoxicity (low nM to pM range) against human cancer cell lines, and are promising vascular disrupting agents (VDAs). As such, these compounds represent lead anticancer agents with potential translatability towards the clinic. Methodology previously established by us (and others) facilitated synthetic access to a variety of structural and functional group modifications necessary to explore structure activity relationship considerations directed towards the development of these (and related) molecules as potential therapeutic agents. During the course of these studies it became apparent that the availability of synthetic methodology to facilitate direct conversion of the phenolic-based compounds to their corresponding aniline congeners would be beneficial. Accordingly, modified synthetic routes toward these target phenols (benzosuberene 1 and dihydronaphthalene 3) were developed in order to improve scalability and overall yield [45-57% (1) and 32% (3)]. Moreover, benzosuberene-based phenolic analogue 1 and separately dihydronaphthalene-based phenolic analogue 3 were successfully converted into their corresponding aniline analogues 2 and 4 in good yield (>60% over three steps) using a palladium catalyzed amination reaction. [ABSTRACT FROM AUTHOR] more...
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- 2019
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7. Synthesis, characterization, crystal structure and liquid crystal studies of some symmetric naphthalene derivative molecules.
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Srinivasa, H.T., Palakshamurthy, B.S., Devarajegowda, H.C., and Hariprasad, S.
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NAPHTHALENE synthesis , *CRYSTAL structure , *LIQUID crystals , *NAPHTHALENE derivatives , *DIFFERENTIAL scanning calorimetry , *MESOPHASES - Abstract
Abstract The synthesis of a series of symmetrical liquid crystals having naphthalene as the central rigid core and attached to long chain flexible 4′-alkoxybenzoate moiety at positions 2,6 - of the aromatic ring are reported. The mesophase behavior of the molecules was investigated using differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction studies. The studies reveal that the synthesized compounds exhibit stable enantiotropic mesophase of Smectic A (SmA) and Nematic (N) phase. The mesophase appearance is independent of the length of the alkyl chain. The molecular structure was determined by single crystal X-ray diffraction technique. The derivative with n- heptyloxy- flexible chain crystallizes under triclinic, P 1 ¯ space group with unit cell dimension a = 5.569(3) Å, b = 10.540(5) Å, c = 15.254(9) Å, α = 73.434(18)o, β = 80.807(19)o and γ = 82.02(2)o, V = 843.1(8) Å3. The dihedral angle between the naphthalene ring system and the benzoate moiety is 63.63(2)o. Graphical abstract Image Highlights • We have synthesized symmetric naphthalene centered molecules. • All the molecules were characterized by UV, IR, NMR analysis. • Liquid crystal property was evaluated by DSC and POM techniques. • Single crystal structure was confirmed by X-ray analysis. [ABSTRACT FROM AUTHOR] more...
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- 2018
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8. An air-stable and solution processable tetracarboxydiimide-based materials with tunable charge transport properties.
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Daskeviciene, Maryte, Urnikaite, Simona, Planciunaite, Greta, Malinauskas, Tadas, Gruodis, Alytis, Viliunas, Mindaugas, Kamarauskas, Egidijus, Gaidelis, Valentas, Jankauskas, Vygintas, and Getautis, Vytautas more...
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IONIZATION energy , *ORGANIC field-effect transistors , *ORGANIC light emitting diodes , *NAPHTHALENE synthesis , *THERMOGRAVIMETRY - Abstract
Novel bipolar molecules based on naphthalene- ( V555 ) and perylene- ( V565 ) tetracarboxydiimide core, bearing 1-phenyl-1,2,3,4-tetrahydroquinoline end capping hole transporting groups, were designed and synthesized. Electro-optical and thermal measurements, such as UV/VIS, charge mobility, ionization potential, thermogravimetric analysis, and differential scanning calorimetry, were carried out to characterize the new materials. V555 and V565 showed bipolar behavior with both hole and electron mobilities under ambient conditions without any protection from oxygen or moisture. The gelation of V565 was observed that provides the ability to tune the charge transport properties. [ABSTRACT FROM AUTHOR] more...
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- 2018
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9. Ligand and solvent control of selectivity in the C–H activation of a pyridylimine-substituted 1-naphthalene; a combined synthetic and computational study.
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Simayi, Rena, Gillbard, Simone M., Cross, Warren B., Hope, Eric G., Singh, Kuldip, and Solan, Gregory A.
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NAPHTHALENE derivatives , *NAPHTHALENE synthesis , *THERMOLYSIS - Abstract
The pyridylimine-substituted 1-naphthalenes, 2-(1-C10H7)-6-{CR=N(2,6-i-Pr2C6H3)}C5H3N (R = Me HLMe, H HLH), react with Na2[PdCl4] in acetic acid at elevated temperature to afford either ortho-C–Hnaphthyl activated (LMe)PdCl (2ortho) or the unactivated adduct (HLH)PdCl2 (1b). Alternatively, 1b and its ketimine analogue (HLMe)PdCl2 (1a), can be prepared by treating (MeCN)2PdCl2 with either HLMe or HLH in chloroform at room temperature. Regio-selective ortho-C–H activation to form 2ortho can also be initiated by the thermolysis of 1a in acetic acid, while no reaction occurs under similar conditions with 1b. Interestingly, the C–H activation of HLMe to give 2ortho is found to be reversible with 100% deuteration of the peri-site occurring on reacting Na2[PdCl4] with HLMe in acetic acid-d4. By contrast, heating 1a in toluene gives a 55 : 45 mixture of 2ortho and its peri-activated isomer 2peri. Pure 2peri can, however, be obtained either from (LMe)PdOAc (3peri) by OAc/Cl exchange or by the sequential reactions of 1a with firstly silver acetate then with aqueous sodium chloride. Intriguingly, a peri to ortho interconversion occurs on heating 2peri in acetic acid to give 2ortho. DFT calculations have been used to investigate the C–H activation steps and it is found that in acetic acid ortho-C–H activation is kinetically and thermodynamically favoured but peri-CH activation is kinetically accessible (ΔΔG‡ = 2.4 kcal mol−1). By contrast in toluene, the reaction appears to be irreversible with the difference in barrier height for ortho- and peri-C–H activation being very small within the error of the method (ΔΔG‡ = 0.7 kcal mol−1), findings that are in agreement with the empirically observed product distribution for 2ortho and 2peri. Single crystal X-ray structures are reported for 1a, 1b, 2ortho and 2peri. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
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10. Synthesis of Monodisperse Naphthalene Dendrons for the Application of Dendrimers.
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Jillella, Raveendra, Kim, Jaewoong, Kim, Kun Hee, Han, Jin Wook, and Oh, Chang Ho
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NAPHTHALENE synthesis , *DENDRIMERS , *URETHANE , *SUBSTITUTION reactions , *CARBOXYLATES , *ARYL halides - Abstract
Syntheses of dendrons for dendrimer applications are described using napthyl and urethane derivatives. The napthol, 1‐(3‐hydroxy‐6‐(methoxymethoxy)naphthalen‐1‐yl)ethan‐1‐one (h), was synthesized by employing Au‐catalyzed cyclization of the corresponding propargylic carboxylates. Polynapthol dendrons (i, j, k, and l) were prepared from substitution reactions of napthyl derivative h with alkyl/aryl halides under basic conditions. Branched polyurethane compounds (q, r, and s) were also prepared from addition reactions of 1,3,5‐tris(6‐isocyanteohexyl)‐1,3,5‐triazine‐2,4,6‐trione (p) with various alcohols under Lewis acidic conditions. The photophysical properties of the synthesized compounds h, k, and j were studied. [ABSTRACT FROM AUTHOR] more...
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- 2018
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11. Synthesis of a selective ratiometric fluorescent probe based on Naphthalimide and its application in human cytochrome P450 1A.
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Zhang, Xiuxuan, Zhou, Yan, Gu, Xiaofei, Cheng, Yu, Hong, Manxin, Yan, Liqiang, Ma, Fulong, and Qi, Zhengjian
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FLUORESCENT probes , *NAPHTHALIMIDES , *NAPHTHALENE synthesis , *CYTOCHROME P-450 structure - Abstract
Cytochrome P450s have brought considerable attention to researchers for their significant correlations with metabolic behaviors of procarcinogenic chemicals. To better understand the roles of CYP1A in biological and physiological systems, we developed a novel ratiometric fluorescence probe N-((2-hydroxyl ethoxy) ethyl)− 4-methoxy-1, 8-naphthalimide ( NEMN ) allowing for selectively and sensitively monitoring the target enzymes under physiological conditions and living cells. The probe was designed based on substrate predilection of CYP1A and its outstanding O-dealkylation capacity, and 1, 8-naphthalimide was chosen as fluorophore on account of its desirable photophysical properties. Absorption and emission spectra of the probe solution and reacted metabolism showed obvious red-shift with remarkable colour changes, which indicated that NEMN could be a promising ratiometric detector of CYP1A. Additionally, the selectivity assays displayed that NEMN only sensitive to CYP1A1 and CYP1A2 enzymes with scarce interference of other CYPs. Furthermore, the excellent linear relationships between the ratio of fluorescent intensities and incubation time and enzymes concentration signified time- and concentration- dependence of the probe, which were of desire benefit to quantify and monitor the CYP1A-involved biological behaviors in physiological conditions. The assay in real living samples (Human liver microsomes) further proved the analytical utility of the probe. Finally, the cytotoxicity assay and confocal fluorescence imaging demonstrated that this probe was of great promise for detecting the activity of endogenous CYP1A in human living cells. [ABSTRACT FROM AUTHOR] more...
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- 2018
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12. Stereoselective synthesis of 1,2-annulated-C-Aryl glycosides from carbohydrate-derived terminally unsubstituted dienes and arynes: Application towards synthesis of sugar-fused- or branched- naphthalenes, and C-Aryl glycosides.
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Dubbu, Sateesh, Verma, Ashish Kumar, Parasuraman, Kadigachalam, and Vankar, Yashwant D.
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CHEMICAL synthesis , *GLYCOSIDES , *DIOLEFINS , *NAPHTHALENE synthesis , *DIELS-Alder reaction - Abstract
Synthesis of 1,2-annulated- C -aryl glycosides has been achieved in a stereoselective manner through the Diels-Alder reaction between carbohydrate-derived terminally unsubstituted dienes and in situ generated arynes. In these reactions, formation of sugar-fused (or branched) naphthalenes was also observed and found to be temperature dependent and thus constituting one of the salient features of this work. The synthetic importance of 1,2-annulated- C -aryl glycosides has been explored by transforming them into densely oxygenated products by functionalizing the unsubstituted exo -double bond. Further, 1,2-annulated- C -aryl glycosides give rapid access to C -aryl glycosides in four steps. [ABSTRACT FROM AUTHOR] more...
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- 2018
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13. Synthesis, UV/Vis and Fluorescence studies of Naphthoquinone Pyridyl Tetrazole-based Chemical Probe.
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BALAKRISHNA, K., VIJAYA LAKSHMI, D., MUSTAFA, S., REDDY, K. S., and GHORPADE, T. K.
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NAPHTHOQUINONE , *TETRAZOLES , *NAPHTHALENE synthesis , *DIMETHYLFORMAMIDE , *FLUORESCENCE - Abstract
2-(dimethylamino)-3-(5-(pyridin-2-yl)-1H-tetrazol-1-yl)naphthalene-1,4-dione (2) has been synthesized. The UV/Vis studies of 2-(dimethylamino)-3-(5-(pyridin-2-yl)-1H-tetrazol-1-yl)naphthalene-1,4-dione (2) with different metal ions were performed in aqueous dimethylformamide and were correlated with fluorescence studies of the same. The compound showed higher selectivity and sensitivity for Zn2+ ions. Thus this compound could be utilized as a turn-on probe for fluorescent imaging of Zn2+ ions in living cells. [ABSTRACT FROM AUTHOR] more...
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- 2018
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14. Construction of Polycyclic π‐Conjugated Systems Incorporating an Azulene Unit Following the Oxidation of 1,8‐Diphenyl‐9,10‐bis(phenylethynyl)phenanthrene.
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Konishi, Akihito, Morinaga, Atsushi, and Yasuda, Makoto
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POLYCYCLIC aromatic hydrocarbon analysis , *MOLECULAR structure of polycyclic aromatic hydrocarbons , *MOLECULAR structure of azulene , *OPTOELECTRONICS , *PHENANTHRENE , *NAPHTHALENE synthesis - Abstract
Abstract: Polycyclic aromatic hydrocarbons (PAHs) that incorporate either heptagons or pentagons consist of non‐planar molecular structures with unusual optoelectronic properties, and the design of a relatively simple and efficient method to construct these highly fused π‐conjugated systems with odd‐membered rings is in high demand. This work describes the use of silver(I) cations to promote the efficient synthesis of azulene‐embedded PAH 2, which is a structural isomer of tribenzo[fg,ij,rst]pentaphene 3, via tandem oxidative transannulation between the phenyl and arylethynyl moieties. This method involves a carbophilic interaction of the silver(I) cation with the acetylene units, which facilitates an electron transfer in the initial step. The synthesized PAH 2 and the protonated cation 2 H⋅BF4 were fully characterized by X‐ray crystallographic analysis, electronic absorption, electrochemical measurement, and quantum chemical calculation. The azulene‐embedded PAH 2 exhibited a low‐energy absorption band and amphoteric redox events, which were characterized as non‐alternant characteristics originating from the azulene unit. [ABSTRACT FROM AUTHOR] more...
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- 2018
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15. A novel naphthalimide-based probe for highly sensitive and selective recognition of fluoride ion.
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Yuan, Xiao, Zhao, Cheng-Xi, Lu, Yun-Xiang, Shen, Yong-Jia, and Wang, Cheng-Yun
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INGESTION , *PHYSIOLOGICAL effects of fluorides , *NAPHTHALIMIDES , *NAPHTHALENE derivatives , *NAPHTHALENE synthesis - Abstract
Considering the excessive ingestion of fluoride ion (F − ) may result in many diseases, herein, by introducing 2-hydroxy-1-naphthaldehyde azine framework to 1,8-naphthalimide derivatives, we have developed a unique colorimetric/fluorometric probe (NYL) for detection of fluoride. The response of NYL toward F − is an integration of ESIPT and PET processes with a large stokes’ shift (173 nm). The striking color change from yellow to light-purple and fluorescent quenching of probe NYL can be observed only in the presence of fluoride ions. Furthermore, 1 H NMR titration indicates the probe undergoes the deprotonation of hydroxyl through the Hydrogen-bond interaction between phenolic O H and F − ions. [ABSTRACT FROM AUTHOR] more...
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- 2018
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16. Simple Synthesis of Functionalized 2‐Phosphanaphthalenes.
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Mei, Yanbo, Wu, Dong‐Jun, Borger, Jaap E., and Grützmacher, Hansjörg
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NAPHTHALENE synthesis , *EXTRUSION process , *PHTHALAZINE , *HETEROCYCLIC compounds , *COORDINATE covalent bond , *TRANSITION metal complexes - Abstract
Abstract: A simple synthesis of sodium 2‐phosphanaphthalene‐3‐olate (
1 ) based on the extrusion of N2 from phthalazine using Na[OCP] is reported. This heterocycle can be readily functionalized at the negatively charged oxygen center using a variety of electrophilic substrates. The coordination chemistry of both1 and its neutral derivatives was explored, revealing their facile use as P‐donor ligands for late‐transition‐metal complexes. [ABSTRACT FROM AUTHOR] more...- Published
- 2018
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17. Antibacterial naphthoquinone derivatives targeting resistant strain Gram-negative bacteria in biofilms.
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Novais, Juliana S., Moreira, Caroline S., Silva, Ana Carolina J.A., Loureiro, Raquel S., Sá Figueiredo, Agnes Marie, Ferreira, Vitor F., Castro, Helena C., and da Rocha, David R.
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NAPHTHOQUINONE , *ANTIBACTERIAL agents , *DRUG resistance in bacteria , *BIOFILMS , *NAPHTHALENE synthesis , *THERAPEUTICS - Abstract
The aims of this study were the planning, synthesis and in vitro evaluation of 2-hydroxy-3-phenylsulfanylmethyl-[1,4]-naphthoquinones against Gram-negative and Gram-positive strains, searching for potential lead compounds against bacterial biofilm formation. A series of 12 new analogs of 2-hydroxy-3-phenylsulfanylmethyl-[1,4]-naphthoquinones were synthesized by adding a thiol and different substituents to a ο -quinone methide using microwave irradiation. The compounds were tested against Gram-positive ( Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, S. simulans ATCC 27851, S. epidermidis ATCC 12228 and a hospital Methicillin-resistant S. aureus (MRSA) strain), as well as Gram-negative ( Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, P. aeruginosa ATCC 15442, Proteus mirabilis ATCC 15290, Serratia marcescens ATCC 14756, Klebsiella pneumoniae ATCC 4352 and Enterobacter cloacae ATCC 23355) strains, using the disk diffusion method. Ten compounds showed activity mainly against Gram-negative strains with a minimal inhibitory concentration (MIC = 4–64 μg/mL) within the Clinical and Laboratory Standards Institute (CLSI) levels. The biofilm inhibition data showed compounds, 9e , 9f , 9j and 9k , are anti-biofilm molecules when used in sub-MIC concentrations against P. aeruginosa ATCC 15442 strain. Compound ( 9j ) inhibited biofilm formation up to 63.4% with a better profile than ciprofloxacin, which is not able to prevent biofilm formation effectively. The reduction of P. aeruginosa ATCC 15442 mature biofilms was also observed for 9e and 9k . The structure modification applied in the series resulted in 12 new naphthoquinones with antimicrobial activity against Gram-negative bacteria strains ( E. coli ATCC 25922, P. aeruginosa ATCC 27853 and ATCC 15442). Four compounds decreased P. aeruginosa biofilm formation effectively. [ABSTRACT FROM AUTHOR] more...
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- 2018
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18. Effect of thermal treatment on morphology and catalytic performance of NiW/Al2O3 catalysts prepared using citric acid as chelating agent.
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Pereyma, V. Yu., Klimov, O.V., Prosvirin, I.P., Gerasimov, E. Yu., Yashnik, S.A., and Noskov, A.S.
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CITRIC acid , *CARBOXYLIC acids , *X-ray photoelectron spectra , *NAPHTHALENE synthesis ,PHYSIOLOGICAL effects of nickel - Abstract
In the present work, NiW/Al 2 O 3 catalyst was prepared with the use of citric acid and thermally treated at temperatures of 120, 220, 300 and 450 °C. It was shown that the thermal treatment at temperatures of 220–300 °C leads to decomposition of citrate ligands, 450 °C – to the almost complete removal of organic carbon. HRTEM of the sulfided catalysts showed that stacking number of WS 2 increases with the increase of the thermal treatment temperature while the WS 2 slab length has minimum at 220 °C. The results of XPS indicated that the sulfidation degree of tungsten and nickel decreases with the increase of the thermal treatment temperature. The catalyst thermally treated at 300 °C resulted to be most active in DBT HDS, quinoline HDN and naphthalene hydrogenation reactions. The higher activity of this catalyst in comparison with the samples thermally treated at 120 °C and 220 °C can be explained by an increased stacking degree of the sulfide WS 2 slabs while maintaining a small length of sulfide slabs and by a smaller carbon content that can impede access to the active sites. The calcination at 450 °C leads to low activity due to the low dispersion of the active component and a decrease in the degree of sulfidation of tungsten and nickel. [ABSTRACT FROM AUTHOR] more...
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- 2018
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19. A NOVEL 1,8-NAPHTHALIMIDE PROBE FOR SELECTIVE DETERMINATION OF Hg2+ IN A WIDE pH WINDOW.
- Author
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Krasteva, Paoleta V., Dimitrova, Margarita D., Georgiev, Nikolai I., and Bojinov, Vladimir B.
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NAPHTHALIMIDES , *NAPHTHALENE synthesis , *FLUOROPHORE synthesis , *ABSORPTION , *FLUORIMETRY - Abstract
This paper reports the synthesis and photophysical investigation of a novel 1,8-naphthalimide fluorophore containing 2-amino-1,3,4-thiadiazole fragment at C-4 position. Absorption and fluorescence characteristics of the dye as a function of pH were investigated in water/ethanol (1:1, v/v) solution. It was found that the synthesized 1,8-naphthalimide did not show significant changes in the emission properties in a wide pH range. Furthermore the ability of the synthesized compound to detect cations was evaluated by the changes in its fluorescence intensity in the presence of metal ions (Co2+, Cu2+, Fe3+, Ni2+, Pb2+, Cd2+, Zn2+ and Hg2+). Only Hg2+, among the tested metal ions, was efficiently detected due to the aggregation caused quenching process. The results obtained indicate the potential of the novel compound acting as a fluorescent "onoff" switch for selective determination of Hg2+ in a wide pH window. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
20. Synthesis, photophysical studies, and application of novel 2,7-bis((1-butyl-1H-1,2,3-triazol-4-yl)methoxy)naphthalene as a highly selective, reversible fluorescence chemosensor for detection Fe3+ ions.
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Singh, Harjinder, Rajeshwari, M, and Khurana, J.M.
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CHEMORECEPTORS synthesis , *NAPHTHALENE synthesis , *FLUORESCENCE , *FRONTIER orbitals , *IRON ions - Abstract
The new reversible turn-off fluorescence chemosensor 2,7-bis((1-butyl-1 H -1,2,3-triazol-4-yl)methoxy)naphthalene for selective detection of Fe 3+ ions has been designed and synthesized using a multicomponent approach. The absorption and emission characteristics of this new chemosensor were studied in different solvents of varying polarities. The ground and excited state dipole moments were determined experimentally by solvatochromic methods and theoretically using DFT/TD-DFT calculations. The effect of common metal ions on emission spectra was investigated. The results showed that it can be used as reversible turn-off fluorescence chemosensor to determine Fe 3+ ions with high selectivity among a series of other common cations. The binding stoichiometry of chemosensor with Fe 3+ ions and association constant was investigated using global fit analyses as proposed by Thordarson. The mechanism of fluorescence quenching was studied by using a Stern-Volmer plot. The linear range of the chemosensor for detection of Fe 3+ ions was found to be 8.0 × 10 −7 M to 1.0 × 10 −5 M with limit of detection (LOD) of 8.7 × 10 −7 M and limit of quantification (LOQ) of 2.6 × 10 −6 M. The Frontier molecular orbitals (FMO) analysis and chemical reactivity indices of this new chemosensor were also studied using DFT/TD-DFT calculations. The non-linear optical properties were also investigated. The values of total polarizability and first-order hyperpolarizability for the chemosensor were found to be higher than the standard urea molecule. Thus it can also be used as a potential NLO material. The thermodynamic parameters were also investigated. [ABSTRACT FROM AUTHOR] more...
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- 2018
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21. A Dipleiadiene‐Embedded Aromatic Saddle Consisting of 86 Carbon Atoms.
- Author
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Pun, Sai Ho, Chan, Chi Kit, Luo, Jiye, Liu, Zhifeng, and Miao, Qian
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POLYCYCLIC aromatic compounds , *NAPHTHALENE synthesis , *DENSITY functional theory , *HEPTAGON , *STEREOCHEMISTRY - Abstract
Abstract: This study presents a new type of negatively curved nanographene (C86H32) that contains an unprecedented pattern of heptagons. A
tert ‐butylated derivative of C86H32 was successfully synthesized using tetrabenzodipleiadiene as a key building block. This synthesis involved a ring expansion reaction as a key step to form the seven‐membered rings in the framework of tetrabenzodipleiadiene. The single‐crystal structure reveals a saddle‐shaped molecule with a highly bent naphthalene moiety at the center of the polycyclic backbone. As found from the DFT calculations, this aromatic saddle is flexible at room temperature and has a saddle‐shaped geometry as the dominant conformation. The DFT calculations along with experimental results show that the attachment oft ‐butyl groups to the central tetrabenzodipleiadiene moiety of nanographene C86H32 can stabilize the saddle conformation and make this nanographene less flexible. [ABSTRACT FROM AUTHOR] more...- Published
- 2018
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22. Highly Stable Molecular Borromean Rings.
- Author
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Lu, Ye, Lin, Yuejian, Li, Zhenhua, and Jin, Guoxin
- Subjects
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NAPHTHALENE synthesis , *MOLECULAR structure , *SOLUTION (Chemistry) , *CHEMICAL stability , *MONOMERS - Abstract
A series of Cp*Rh‐based molecular Borromean rings (BRs) are prepared from naphthazarine or metallaligand. Some of as‐synthesized BRs display high stability and are formed in high yields in solution. The reason is related to the length ratio of the long‐arm linker and short‐arm linker, where smaller aspect ratios of the metallarectangles promote improved stability and yields of the BRs in solution. Increasing the width of the metallaligand or pyridyl ligand hinders the formation of BRs and leads to unoccupied monomeric rectangles, which were further used as catalysts for the acyl transfer reaction between
N ‐acetylimidazole and (4‐(pyridin‐4‐yl)phenyl) methanol. [ABSTRACT FROM AUTHOR] more...- Published
- 2018
- Full Text
- View/download PDF
23. Facile three-step synthesis and photophysical properties of [8]-, [9]-, and [12]cyclo-1,4-naphthalene nanorings via platinum-mediated reductive elimination.
- Author
-
Jia, Hongxing, Gao, Yuyue, Huang, Qiang, Cui, Shengsheng, and Du, Pingwu
- Subjects
- *
NAPHTHALENE synthesis , *PLATINUM , *CARBON nanotubes - Abstract
Herein we report a facile three-step synthesis of [8]-, [9]-, and [12]cyclo-1,4-naphthalene nanorings as the conjugated segments of carbon nanotubes. The nanorings were created via a platinum-mediated assembly of 1,4-naphthalene-based units and subsequent reductive elimination in the presence of triphenylphosphine. This present platinum-mediated approach is attractive because of its simple three-step process to produce the targeted nanorings in a high overall yield. In addition, their photophysical properties were studied using UV-vis spectroscopy and photoluminescence (PL) spectroscopy, which further revealed their unique size-dependent properties. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
- Full Text
- View/download PDF
24. Experiment and Theory of Bimetallic Pd-Catalyzed α-Arylation and Annulation for Naphthalene Synthesis
- Author
-
Mariur Rodriguez Moreno, Stacey J. Smith, Daniel H. Ess, David J. Michaelis, Kyle J. Gassaway, S. Hadi Nazari, Erin E. Martinez, Samuel R. Himes, Manase F. Matu, Gabriel A. Valdivia-Berroeta, Chloe C. Ence, and Samantha G. Larsen more...
- Subjects
Annulation ,Chemistry ,Naphthalene synthesis ,General Chemistry ,Bimetallic strip ,Medicinal chemistry ,Catalysis - Published
- 2021
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25. 3,4,5-Trimethylphenol and Lewis Acid Dual-Catalyzed Cascade Ring-Opening/Cyclization: Direct Synthesis of Naphthalenes.
- Author
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He Ma, Xiu-Qin Hu, Yong-Chun Luo, and Peng-Fei Xu
- Subjects
- *
PHENOL , *LEWIS acids , *RING-opening reactions , *NAPHTHALENE synthesis , *CYCLOPROPANE - Abstract
A 3,4,5-trimethylphenol and Lewis acid dual-catalyzed cascade reaction of donor-acceptor (D-A) cyclopropanes via ring-opening and cyclization is developed. In this reaction, a phenolic compound was used as a covalent catalyst for the first time. Additionally, control experiments proved that 3,4,5-trimethylphenol completed the catalytic cycle by accomplishing the C-C bond cleavage. Using this strategy, a wide variety of substituted naphthalenes has been synthesized from D-A cyclopropanes in moderate to high yields under mild conditions. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
26. Processing and degradation behavior of porous magnesium scaffold for biomedical applications.
- Author
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Dutta, Sourav, Bavya Devi, K., and Roy, Mangal
- Subjects
- *
POROUS materials , *DEGRADATION of steel , *NAPHTHALENE synthesis , *SCAFFOLD proteins , *COMPUTED tomography - Abstract
Porous magnesium has the potential to be used as degradable bone scaffolds. In this study, porous magnesium scaffolds were fabricated through powder metallurgy route utilizing spherical naphthalene particle as porogen. Porogen was removed at 120 °C for 24 h followed by sintering at 550 °C for 2 h in argon atmosphere. Micro-computed tomography (micro CT) results indicated that scaffolds have interconnected porous structure with an equivalent pore diameter of nearly 60 µm. Compressive strength of the scaffolds was found in the range of 24 ± 4.54 MPa to 184 ± 9.9 MPa and decreased with increasing porogen content. In vitro degradation study in phosphate buffered saline (PBS) showed that scaffold degradation behavior was governed by its porosity content. Our results indicate that modulating the porogen content we can tailor the mechanical and degradation behavior of the Mg scaffolds to the application need. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
27. Palladium-Catalyzed Double Suzuki Reactions: Synthesis of Dibenzo[4,5:6,7]cyclohepta[1,2,3- de]naphthalenes.
- Author
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Li, Xin, Han, Jian‐Wei, Zhang, Yan‐Xia, and Wong, Henry N. C.
- Subjects
PALLADIUM catalysts ,NAPHTHALENE synthesis ,SUZUKI reaction - Abstract
As an indispensable member in the family of polycyclic aromatic hydrocarbons (PAHs), the synthesis of dibenzo[4,5:6,7]cyclohepta-[1,2,3-de]naphthalene (DBnaphthalene) has not been recorded, despite the fact that similar structure of this moiety exists widely in many popular PAHs with unique optical and electronical properties. Herein we report the first synthesis of dibenzo[4,5:6,7]cyclohepta-[1,2,3-de]naphthalene and its derivatives using palladium-catalyzed double Suzuki coupling reactions. These DBnaphthalenes are expected to be useful for the 'bottom-up' synthesis of functional aromatic molecules. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
28. Synthesis of Octaaryl Naphthalenes and Anthracenes with Different Substituents.
- Author
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Suzuki, Shin, Itami, Kenichiro, and Yamaguchi, Junichiro
- Subjects
- *
NAPHTHALENE synthesis , *ANTHRACENE , *SUBSTITUENTS (Chemistry) , *THIOPHENES , *COUPLING reactions (Chemistry) - Abstract
A synthesis of multiply arylated naphthalenes and anthracenes with eight different substituents has been accomplished. The key intermediates are tetraarylthiophene S-oxides, which are synthesized through a method involving sequential C−H arylation and cross-coupling from 3-methoxythiophene, followed by oxidation of the sulfur atom. The resulting tetraarylthiophene S-oxides can be converted into a tetraaryl benzynes or naphthalynes and then merged through [4+2] cycloaddition reaction with another tetraarylthiophene S-oxide, thereby resulting in the programmed synthesis of octaarylnaphthalenes and octaarylanthracenes. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
29. A dual-function probe based on naphthalene diimide for fluorescent recognition of Hg2+ and colorimetric detection of Cu2+.
- Author
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Zong, Luyi, Wang, Can, Song, Yuchen, Xie, Yujun, Zhang, Pan, Peng, Qian, Li, Qianqian, and Li, Zhen
- Subjects
- *
NAPHTHALENE derivatives , *FLUORESCENT probes , *MERCURY , *COPPER ions , *NAPHTHALENE synthesis , *INTRAMOLECULAR charge transfer , *COLORIMETRIC analysis - Abstract
The core-substituted naphthalene diimide ( NDI-6 ) as a dual-function probe was synthesized conveniently, which can monitor Hg 2+ by fluorescent response and serve as a naked-eye detector towards Cu 2+ . The strong red emission induced by the addition of Hg 2+ can be ascribed to the inhibition of the twisted intramolecular charge transfer (TICT) in the excited state, based on the experimental data and theory calculation. Meanwhile, NDI-6 could be used as a reversible fluorescent probe towards Hg 2+ with the aid of I − as test strips, which can be applied into the detection of real samples. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
30. Droplet Coalescence Phenomena during Liquid-Liquid Heterogeneous Reactions in Microreactors.
- Author
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Xin Pu, Guangxiao Li, Yang Song, Minjing Shang, and Yuanhai Su
- Subjects
- *
COALESCENCE (Chemistry) , *NAPHTHALENE synthesis , *SULFONATION , *HETEROGENEOUS catalysis , *MICROREACTORS , *LIQUID-liquid interfaces - Abstract
The sulfonation of naphthalene with sulfuric acid to produce naphthalene sulfonic acid was carried out in capillary microreactors as a model liquid-liquid heterogeneous reaction to study droplet coalescence phenomena. The effects of various factors associated with droplet coalescence or the reaction kinetics, such as capillary length (residence time), reaction temperature, molar ratio of reactants, and capillary wall wetting properties, on the reaction performance were investigated. In particular, the influence of droplet coalescence on the specific interfacial area, the mass transfer rate, and the reaction performance was evaluated in detail. Surprisingly, the specific interfacial area could decrease up to 93% along the flow direction in the capillary microreactor with the droplet coalescence. Interestingly, the microreactor wall surface properties were found to affect the reaction performance significantly. Moreover, the Hatta number was evaluated, which reflected the competition between the mass transfer and the reaction during the sulfonation in the capillary microreactors with droplet coalescence. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
31. Synthetic bioactive novel ether based Schiff bases and their copper(II) complexes.
- Author
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Shabbir, Muhammad, Akhter, Zareen, Ismail, Hammad, and Mirza, Bushra
- Subjects
- *
SCHIFF bases , *COPPER compounds synthesis , *AMINE synthesis , *LIGANDS (Chemistry) , *ANTIOXIDANTS , *NAPHTHALENE synthesis - Abstract
Novel ether based Schiff bases (HL 1 - HL 4 ) were synthesized from 5-chloro-2-hydroxy benzaldehyde and primary amines (1-amino-4-phenoxybenzene, 4-(4-aminophenyloxy) biphenyl, 1-(4-aminophenoxy) naphthalene and 2-(4-aminophenoxy) naphthalene). From these Schiff bases copper(II) complexes (Cu(L 1 ) 2 -Cu(L 4 ) 2 )) were synthesized and characterized by elemental analysis and spectroscopic (FTIR, NMR) techniques. The synthesized Schiff bases and copper(II) complexes were further assessed for various biological studies. In brine shrimp assay the copper(II) complexes revealed 4-fold higher activity (LD 50 3.8 μg/ml) as compared with simple ligands (LD 50 12.4 μg/ml). Similar findings were observed in potato disc antitumor assay with higher activities for copper(II) complexes (IC 50 range 20.4–24.1 μg/ml) than ligands (IC 50 range 40.5–48.3 μg/ml). DPPH assay was performed to determine the antioxidant potential of the compounds. Significant antioxidant activity was shown by the copper(II) complexes whereas simple ligands have shown no activity. In DNA protection assay significant protection behavior was exhibited by simple ligand molecules while copper(II) complexes showed neutral behavior (neither protective nor damaging). [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
32. A naphthalene benzimidazole-based chemosensor for the colorimetric and on-off fluorescent detection of fluoride ion.
- Author
-
Li, Dongmei, Zhong, Zhimin, Zheng, Gengxiu, and Tian, Zhongzhen
- Subjects
- *
NAPHTHALENE synthesis , *BENZIMIDAZOLES , *CHEMICAL synthesis , *CHEMORECEPTORS , *COLORIMETRIC analysis , *METHODS in emission spectroscopy , *PHYSIOLOGY - Abstract
A novel naphthalene benzimidazole (NBI)-based chemosensor ( D2 ) was developed for fluoride ion (F − ) detection. The absorption spectrum of D2 changed dramatically from yellow to blue in the visible region accompanied with a 225 nm red shift of its absorption maximum upon the addition of F − in DMSO. D2 also exhibited a fluorescence turn-off response towards the fluoride ion. The emission intensity of D2 decreased drastically along the increasing F − concentration and the detection limit for F − was as low as 3.2 × 10 − 9 mol/L. 1 H NMR and HRMS-ESI results indicated that the formation of NBI-O − through the desilylation reaction of F − with NBI-OSi was responsible for the spectral changes. Overall, this kind of NBI-type molecules represent a new type chemosensor for the spectral detection of fluoride ion in solution. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
33. Synthesis and characterization of tetraoctyloxy substituted naphthalenophanedienes.
- Author
-
Yu, Chin-Yang, Yu, Sheng-Hao, Wen, Shih-Hao, and Wang, Chao-Chi
- Subjects
- *
NAPHTHALENE synthesis , *X-ray crystallography , *NUCLEAR magnetic resonance spectroscopy , *PYROLYSIS , *STEVENS rearrangement , *BENZYNES - Abstract
Tetraoctyloxy-substituted naphthalenophanedienes were synthesized from tetraoctyloxy-substituted dithia[3.3]naphthalenophanes via sequential benzyne Stevens rearrangement, oxidation, and pyrolysis reactions. Surprisingly, only the pseudo-geminal isomer of tetraoctyloxy-substituted dithia[3.3]naphthalenophane was obtained after cyclization of the corresponding starting materials. The structures of the pseudo-geminal isomers of tetraoctyloxy-substituted dithia[3.3]naphthalenophane and tetraoctyloxy-substituted naphthalenophanediene were fully determined by nuclear magnetic resonance spectroscopy, high resolution mass spectrometry, and X-ray crystallography. The pseudo-geminal and pseudo-meta diastereomers of tetraoctyloxy-substituted naphthalenophanedienes were isolated by multiple fractional recrystallization from hexane at 5 °C. The solid state structure of the pseudo-geminal isomer of tetraoctyloxy-substituted naphthalenophanediene revealed strongly distorted naphthyl rings with high levels of ring strain. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
34. Synthesis and characterization of binaphthalene-2,2′-diamine-functionalized gold nanoparticles.
- Author
-
Liu, Lijun, Yu, Long, Chen, Xinfeng, Yue, Ji, Asiri, Abdullah, Marwani, Hadi, Huang, Dejian, and Wang, Suhua
- Subjects
- *
NAPHTHALENE synthesis , *POLYMERIZATION , *GOLD nanoparticles , *DIAMINES , *LIGANDS (Biochemistry) - Abstract
Gold nanoparticles 1.7 and 54 nm in diameters have been synthesized and functionalized successfully with their surfaces engineered using two atropisomeric capping ligands, 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) and 1,1′-binaphthalene-2,2′-diamine (DABN), respectively. A systematic study to compare the two different gold nanoparticles is presented using multiple material characterization techniques. It was found that the two systems show different capping mechanism and hence differ in their intrinsic core and surface properties. The compound BINAP plays only surface capping agent and stabilizes the gold nanoparticles, resulting in small particle size and suppressed surface plasmon resonance absorption at 520 nm. The DABN capping ligand is different from BINAP and acts as both reducing and capping agent, causing the reduction of Au (III) to Au (0). The nucleation growth of the gold core occurs in accordance with the polymerization-passivation process by DABN, resulting in a big particle size of 20 nm. A strong surface plasmon resonance band shows a maximum peak at 564 nm, consistent with the Au core size. The simultaneous oxidative polymerization of DABN and the induced metal reduction process lead to the formation of gold nanoparticles encapsulated by a mixture of DABN oligomers or polymers. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
35. Concentration-induced discoloration properties of poly(alkoxynaphthalene)s synthesized by solid-state oxidative coupling polymerization.
- Author
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Bai, Weibin, Yao, Rijin, Guan, Meiqin, Shang, Xianhuo, Lai, Ningshan, Xu, Yanlian, and Lin, Jinhuo
- Subjects
- *
NAPHTHALENE synthesis , *DISCOLORATION , *OXIDATIVE coupling , *POLYMERIZATION , *IRON chlorides , *SOLID state chemistry , *THERMAL stability - Abstract
Poly(alkoxynaphthalene)s were synthesized by grinding 2-alkoxynaphthalenes with FeCl 3 as the oxidant at room temperature via solid-state oxidative coupling polymerization. Based on the structural characterization and analysis, the condensed structure of 1,4-linked polynaphthalenes is the dominant structure of the polymer, accompanied with the formation of intramolecular coupling. The polymers not only exhibit perfect heat-resistant property, but also show the concentration-induced discoloration property. With the continuously increasing polymer concentrations, the maximum fluorescence bands were observed from the ultraviolet region to 520 nm, eventually red shifting to 620 nm at the polymer concentration above 0.1 mg mL −1 . Moreover, the choice of solvent and the extended side-chains can affect the fluorescence spectral changes. In combination with the fluorescence spectral changes of poly(alkoxynaphthalene)s in PMMA films, the concentration-induced discoloration property is mainly dependent on a transition from twisted conformations to planar structures and the formation of polymer aggregates. Moreover, these polymers exhibit obvious enhanced emissions and on/off fluorescent switching which sense THF vapor. It is suggested that poly(alkoxynaphthalene)s are potential materials for fabrication of fluorescence sensors to detect THF efficiently. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
36. TBAI/K2S2O8 Initiated Radical Cyclization to Synthesize β- Arylsulfonyl Naphthalenes from Homopropargylic Alcohols and Sulfonyl Hydrazides.
- Author
-
Yang, Xiaodong, Zhao, Lianbiao, Yuan, Bingxiang, Qi, Zhenjie, and Yan, Rulong
- Subjects
- *
NAPHTHALENE synthesis , *HYDRAZIDES , *SULFONES , *SULFONYL azides , *ALKYNES , *PARKINSON'S disease treatment , *ARYLSULFONATES , *THERAPEUTICS - Abstract
A metal-free radical addition method for the synthesis of β-arylsulfonyl naphthalenes with homopropargylic alcohols and sulfonyl hydrazides has been developed. In this reaction, sulfonyl hydrazide is employed as the source of sulfonyl radical to produce the desired sulfone directly. There is the first example for homopropargylic alcohol through direct intramolecular addition of vinyl radical to arenes with sulfonyl radical, which is initiated by the TBAI/K2S2O8 reaction system and generates the desired products in moderate yields. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
37. Effect of carbon coating on nano-Si embedded SiOx-Al2O3 composites as lithium storage materials.
- Author
-
Kim, Kyungbae, Choi, Hyerang, and Kim, Jae-Hun
- Subjects
- *
PYROLYSIS , *SILICA analysis , *LITHIUM-ion batteries , *NAPHTHALENE synthesis , *COMPOSITE materials synthesis - Abstract
Carbon-coated Si–SiO x –Al 2 O 3 composite materials were prepared via a two-step process involving a high-energy mechanical milling and a pyrolysis reaction, and their electrochemical properties were subsequently examined for use as anode materials for Li-ion batteries. To synthesize the nanocrystalline Si embedded SiO x composite, amorphous SiO 2 and metallic Al were chosen as the best pair of starting materials. First, a simple high-energy mechanical milling process was performed to partially reduce amorphous SiO 2 using Al metal. Al was spontaneously oxidized to Al 2 O 3 ; this resulted in a nanocrystalline Si dispersed amorphous SiO x –Al 2 O 3 phase. Second, the composite was heat-treated in the presence of naphthalene as a carbon source. Through the pyrolysis reaction of naphthalene, an amorphous carbon coating layer was obtained; this layer stabilized the crystal structure of SiO x –Al 2 O 3 . The materials properties of the composites were investigated using various analytical tools. Electrochemical tests showed that the carbon-coated composite electrode exhibited good cycling stability up to 300 cycles. This performance can be attributed to the effect of the carbon coating, which both facilitated fast electronic and Li + ionic transport and played a buffering role in the large volume change of the Si-based anode materials. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
38. Optical, thermal and combustion properties of self-colored polyamide nanocomposites reinforced with azo dye surface modified ZnO nanoparticles.
- Author
-
Hajibeygi, Mohsen, Shabanian, Meisam, Omidi-Ghallemohamadi, Mehrdad, and Khonakdar, Hossein Ali
- Subjects
- *
ARAMID fibers , *MANUFACTURING of nanocomposite materials , *ZINC oxide , *NAPHTHALENE synthesis , *NANOPARTICLES - Abstract
New self-colored aromatic-polyamide (PA) nanocomposites containing azo and naphthalene chromophores were prepared with azo-dye surface-modified ZnO nanoparticles (SMZnO) using solution method in dimethylformamide. The X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) results showed the uniform distribution for ZnO nanoparticles in the PA matrix. The UV–vis spectra of PA/ZnO nanocomposites (PANC) showed a blue shift as well as reduction in absorbance intensities and the photoluminescence studies revealed that the increasing intensities of the violet emission in SMZnO loading. From thermo gravimetric analysis (TGA), the temperature at 10% mass loss (T 10 ) increased from 291.8 °C to 387.6 °C for PANC containing 8 mass% of SMZnO, as well as the char yield enhanced significantly, which was about 23.5% higher than the neat PA. The peak heat release rate resulted from microscale combustion calorimeter (MCC), by 8 mass% loading of SMZnO, decreased about 56.9% lower than the neat PA. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
39. Stereospecificity in Intramolecular Photoredox Reactions of Naphthoquinones: Enantioselective Total Synthesis of (−)-Spiroxin C.
- Author
-
Ando, Yoshio, Hanaki, Atsuko, Sasaki, Ryota, Ohmori, Ken, and Suzuki, Keisuke
- Subjects
- *
NAPHTHALENE synthesis , *QUINONE , *STEREOSPECIFICITY , *OXIDATION-reduction reaction , *INTERMOLECULAR interactions , *CHEMICAL reactions - Abstract
Intramolecular photoredox reactions of naphthoquinone derivatives were found to proceed in a stereospecific manner. This method was used as a basis for the enantioselective total synthesis of (−)-spiroxin C. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
40. Naphthalene formation pathways from phenyl radical via vinyl radical (C2H3) and vinylacetylene (C4H4): computational studies on reaction mechanisms and kinetics.
- Author
-
Wei, Mingrui, Zhang, Tingting, Li, Shunxi, Guo, Guanlun, and Zhang, Dongju
- Subjects
- *
NAPHTHALENE synthesis , *ACETYLENE , *PHENYL compounds , *VINYLATION , *COMBUSTION , *CHEMICAL kinetics - Abstract
The reaction mechanisms of PAH formation from phenyl radical (C6H5) to naphthalene via C2H3 ( C2H3-Path) and C4H4 ( C4H4-Path) were investigated by the G3(MP2, CC) method. The hydrogen abstraction, ring closure, cis- trans isomerization, and disproportionation reactions were considered, as well as their occurred sequence. The results showed that H-abstraction reactions occurred more easily than H-dissociation reactions. The cis- trans conversion reactions in sub-routes of C2H3-Path and C4H4-Path provided the largest barriers of 51, 53, and 36 kcal/mol along their routes, which illustrated that the cis- trans isomerization was energetically costly in the PAH formation process. The entrance barriers of C2H2-Path, C2H3-Path, and C4H4-Path are 6, 8, and 3 kcal/mol, respectively, which indicates that it is easier to add C4H4 to C6H5 compared with adding C2H2 to C2H3. C2H3 additions were highly exothermic with reaction energies greater than 110 kcal/mol, and compared with C2H2 additions, C2H3 additions were irreversible. However, C2H2-Path, C2H3-Path and C4H4-Path involved energy barriers of 20, 32, and 36 kcal/mol, respectively. Considering the high temperature in combustion and the approximate concentrations of C2H3 and C4H4, all three of these pathways could lead to naphthalene in some combustion flames. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
41. Dearomative Intramolecular (4+3) Cycloadditions of Arenes with Epoxy and Aziridinyl Enolsilanes.
- Author
-
Ling, Jesse, Lam, Sarah, Low, Kam-Hung, and Chiu, Pauline
- Subjects
- *
RING formation (Chemistry) , *EPOXIDATION , *BENZENE synthesis , *NAPHTHALENE synthesis , *INTRAMOLECULAR catalysis - Abstract
An intramolecular (4+3) cycloaddition of epoxy and aziridinyl enolsilanes with benzene, naphthalene, and anthracene derivatives is reported. Highly functionalized polycyclic alcohols and amines are generated under relatively mild reaction conditions with yields up to 89 %. Optically enriched cycloadducts are obtained from cycloadditions of enantiomerically pure epoxides and aziridines. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
42. Synthetically tunable iridium(III) bis-pyridine-2-sulfonamide complexes as efficient and durable water oxidation catalysts.
- Author
-
Li, Mo and Bernhard, Stefan
- Subjects
- *
IRIDIUM compound synthesis , *OXIDATION of water , *PHENYLENE compounds , *NAPHTHALENE synthesis , *CATALYST structure - Abstract
A series of phenylene-linked iridium bis-pyridine-2-sulfonamide (bpsa) complexes substituted with electron-donating and electron-withdrawing groups and a new bpsa complex containing naphthalene linkage were synthesized and investigated as efficient and robust water oxidation catalysts. It was found that the oxidation potentials of these substituted complexes are within a broad range, which reflects their effectively tuned electronic structures. Under various water oxidation conditions, diverse kinetics behaviors are observed. The reaction mechanism strongly depends on the structure of the catalyst, and the nature of the oxidant as well as their ratios and concentrations. As evidenced by cyclic voltammetry and DFT calculations, the addition of electron-donating substituents greatly destabilizes the HOMO of the catalyst and thus facilitates the initial oxidation process. On the other hand, the limited driving force provided by the oxidized state of an electron-rich catalyst also impedes efficient water oxidation reactions. The robustness of a water oxidation catalyst is critical, and long-term reactions have exhibited turnover numbers (TONs) of up to 16,200. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
43. A new polymer acceptor containing naphthalene diimide and 1,3,4-thiadiazole for all-polymer solar cells.
- Author
-
Weng, Chao, Gao, Liang, Zhang, Zhiguo, Liu, Zhaoxia, Tan, Songting, and Li, Yongfang
- Subjects
- *
NAPHTHALENE synthesis , *SOLAR cells , *THIADIAZOLES , *NANOSTRUCTURED materials , *POLYETHYLENE - Abstract
ABSTRACT A n-type conjugated polymer containing naphthalene diimide (NDI) and 1,3,4-thiadiazole (TZ) moieties, named PNTZ, has been synthesized and applied for all-polymer solar cells (all-PSCs). By the incorporation of TZ unit into the polymer main chains, the lowest unoccupied molecular orbital level of this polymer has been adjusted effectively. In addition, the electron-acceptor PNTZ shows a broad absorption spectrum in the range of 300-700 nm, and possesses complementary absorption spectrum with the electron-donor PTB7-Th. On the basis of PNTZ as the acceptor and PTB7-Th as the donor, the all-PSCs are fabricated. After optimization, the well blend morphologies with a continuous D/A interpenetrating network are observed and the best all-PSC device exhibits a power conversion efficiency of 4.35% with a high short-circuit current density of 13.26 mA cm−2. This research demonstrates that the TZ-containing polymer PNTZ is a promising non-fullerene acceptor for high efficiency all-PSCs. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 990-996 [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
44. Synthesis, Characterization and Solvatochromic Studies Using the Solvent Polarity Parameter, ENT on 2-Chloro-3-Ethylamino-1,4-Naphthoquinone.
- Author
-
Durairaj, Arulappan, Obadiah, Asir, Ramanathan, Subramanian, Johnson, Princy, Bella, Antony, and Vasanthkumar, Samuel
- Subjects
- *
NAPHTHOQUINONE , *SOLVATOCHROMISM , *NAPHTHALENE synthesis , *ELECTRONIC structure , *PERMITTIVITY , *REFRACTIVE index - Abstract
Quinones are molecules with varied biological activities and electronic properties which are used for important applications [1, 2]. Quinone with a heteroatom substituted, namely 2-chloro-3-ethylamino-1,4-naphthoquinone (N-CAN) was synthesized and characterized by various techniques such as H-NMR, C-NMR, Mass spectroscopy and FT-IR spectroscopy. In this study, the solvatochromic effects on the spectral properties of 2-chloro-3-ethylamino-1,4-naphthoquinone have been investigated in different solvents taking into consideration, the solvent parameters like dielectric constant (ε) and refractive index (η) of different solvent polarities. Using Lippert-Mataga, Bakshiev's, Kawski-Chamma-Viallet and Reichardt equations, the ground state (μ) and excited state (μ) dipole moments were calculated. The angle between the excited state and ground state dipole moments were also calculated. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
45. Novel chiral binaphthalene-linked pyrenes. Synthesis, structure, and spectroscopy.
- Author
-
Zheng, Yingting, Zhao, Luyang, Zhang, Yuehong, Wang, Chiming, Wang, Kang, Qi, Dongdong, and Jiang, Jianzhuang
- Subjects
- *
CHIRALITY , *PYRENE , *NAPHTHALENE synthesis , *MATRIX-assisted laser desorption-ionization , *NUCLEAR magnetic resonance - Abstract
Novel chiral pyrene-binaphthalene compounds, ( R )-/( S )-(13Z,21bZ)-dinaphtho[2,1-e:1′,2′-g]pyreno[4,5-b][1,4]diazocine ( 1 ) and ( R )-/( S )-(3bZ,5Z,7Z,9Z,12bZ,14Z,16Z,18Z)-bis(dinaphtho[2,1-e:1′,2′-g])pyreno[4,5-b:9,10-b′]bis([1,4]diazocine) ( 2 ), were synthesized and characterized by a series of spectroscopic methods including MALDI-TOF mass, NMR, and electronic absorption methods. Their binaphthalene-linked pyrene nature has been unambiguously revealed on the basis of single crystal X-ray diffraction analysis of both ( R )- and ( S )- 1 . In addition, their electronic structure was also investigated on the basis of DFT calculations. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
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46. Synthesis and characterization of a photochromic magnesium(II) coordination polymer based on a naphthalene diimide ligand.
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Liu, Jian-Jun, Liu, Teng, and Huang, Chang-Cang
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COORDINATION polymers , *MAGNESIUM compounds , *NAPHTHALENE synthesis - Abstract
Naphthalene diimides, which are planar, chemically robust and redox-active, are an attractive class of electron-deficient dyes, which can undergo a single reversible one-electron reduction to form stable radical anions in the presence of electron donors upon irradiation. This makes them excellent candidates for organic linkers in the construction of photochromic coordination polymers. Such a photochromic one-dimensional linear coordination polymer has been prepared using N, N′-bis(3-carboxyphenyl)naphthalene-1,8:4,5-tetracarboximide (H2BBNDI). Crystallization of H2BBNDI with magnesium nitrate in an N, N′-dimethylformamide (DMF)/ethanol/H2O mixed-solvent system under solvothermal conditions afforded the one-dimensional coordination polymer catena-poly[[bis(dimethylformamide-κ O)magnesium(II)]-bis[μ- N-(3-carboxylatophenyl)- N′-(3-carboxylphenyl)naphthalene-1,8:4,5-tetracarboximide-κ2 O: O′]], [Mg(C28H13N2O8)2(C3H7NO)2] n. The asymmetric unit contains half of a magnesium cation, one HBBNDI− ligand and one DMF molecule. Two partially deprotonated HBBNDI− ligands bridge two magnesium cations to form a one-dimensional chain. Strong inter-chain π-π interactions between the naphthalene rings of the HBBNDI− ligand and the imide rings of adjacent chains provide a two-dimensional structure. The supramolecular three-dimensional framework is stabilized by π-π interactions between naphthalene rings of neighbouring two-dimensional supramolecular networks. The complex exhibits a reversible photochromic behaviour, which may originate from the photoinduced electron-transfer generation of radicals in the HBBNDI− ligand. [ABSTRACT FROM AUTHOR] more...
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- 2017
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47. Synthesis and characterization of arylenevinylenearylene-naphthalene diimide copolymers as acceptor in all-polymer solar cells.
- Author
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Xue, Lingwei, Yang, Yankang, Bin, Haijun, Zhang, Zhi ‐ Guo, Zhang, Jing, Yang, YunXu, and Li, Yongfang
- Subjects
- *
COPOLYMERS , *NAPHTHALENE synthesis , *SOLAR cells , *CONJUGATED polymers , *IMIDES , *COUPLING agents (Chemistry) - Abstract
ABSTRACT Two n-type conjugated D-A copolymers, P(TVT-NDI) and P(FVF-NDI) with thienylene-vinylene-thienylene (TVT) or furanylene-vinylene-furanylene (FVF) as donor (D) units and naphthalene diimide (NDI) as the acceptor (A) units, were synthesized by the Stille coupling copolymerization. The two polymers possess good solubility, high thermal stability, and broad absorption bands with absorption edges at 866 nm for P(TVT-NDI) and 886 nm for P(FVF-NDI). The LUMO energy levels of P(TVT-NDI) and P(FVF-NDI) are −3.80 eV and −3.76 eV respectively, so the two polymers are suitable for the application as acceptor in blending with most polymer donor in PSCs based on the energy level matching point of view. All polymer solar cells (all-PSCs) were fabricated with P(TVT-NDI) or P(FVF-NDI) as acceptor and medium bandgap polymer J51 as donor for investigating the photovoltaic performance of the two n-type conjugated polymer acceptors. And higher power conversion efficiency of 6.43% for P(TVT-NDI) and 5.21% for P(FVF-NDI) was obtained. The results indicate that arylenevinylenearylene-naphthalene diimide copolymer are promising polymer acceptor for all-PSCs. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1757-1764 [ABSTRACT FROM AUTHOR] more...
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- 2017
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48. Nam7 Hydroxylase Is Responsible for the Formation of the Naphthalenic Ring in the Biosynthesis of Neoansamycins.
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Juanli Zhang, Shanren Li, Xingkang Wu, Zhixing Guo, Chunhua Lu, and Yuemao Shen
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- *
HYDROXYLASES , *NAPHTHALENE synthesis , *BENZENE synthesis , *ANSAMYCINS , *RING formation (Chemistry) - Abstract
Ten new benzenic ansamycins, 5,10-seco-neoansamycins A-J (1-10), were isolated from the nam7-disrupted mutant strain SR201nam1OEδnam7. These are the benzenic counterparts of the neoansamycins, which provide direct evidence that the putative hydroxylase Nam7 is involved in the formation of naphthalenic ring in neoansamycin biosynthesis and connect benzenic and naphthalenic ansamycins for the first time. [ABSTRACT FROM AUTHOR] more...
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- 2017
- Full Text
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49. A Very Simple Synthesis of Annelated λ³- and λ5-Phosphanaphthalenes.
- Author
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Zhang, Lujun, Yang, Feichao, Tao, Guanyu, Qiu, Liqi, Duan, Zheng, and Mathey, François
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- *
NAPHTHALENE synthesis , *ANNEALING of metals , *OPTICAL properties , *ALKYL compounds , *AROMATIC compounds , *THERMOLYSIS - Abstract
ortho-Phosphinobenzonitriles (or thieno, pyridino analogues) react with dimethyl acetylenedicarboxylate between -78 °C and room temperature to give annelated λ5-phosphanaphthalenes. Interesting variations of the fluorescence properties are observed when the R substituents at P are alkyl or aryl. When R = tBu, the thermolysis of the product affords the corresponding trivalent phosphanaphthalene. [ABSTRACT FROM AUTHOR] more...
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- 2017
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50. Establishing Consensus Stereostructures for the Naphthoquinonopyrano-γ-lactone Natural Products (-)-Arizonin B1 and (-)-Arizonin C1 by Total Syntheses. Diastereocontrol of Oxa-Pictet-Spengler Cyclizations by Protective-Group Optimization.
- Author
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Neumeyer, Markus and Brückner, Reinhard
- Subjects
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HYDROXYLATION , *PICTET-Spengler reaction , *NAPHTHALENE synthesis , *DIELS-Alder reaction , *ARYNE - Abstract
Previous total syntheses of arizonin C1 ( 4) led to opposite assignments of its absolute configuration. Here, we report the fourth total synthesis thereof. In addition, we disclose the first total synthesis of arizonin B1 ( 3) proceeding differently than via arizonin C1. The stereocenters of the two targets stemmed from an asymmetric dihydroxylation and an ensuing oxa-Pictet-Spengler cyclization. Their configurations were in line with Fernandes' assignments. Protective-group variation in the substrate modulated the diastereoselectivity of the Pictet-Spengler cyclization between 77:23 in favor of a trans disubstitution at C-3a vs. C-5 - used for preparing the natural (-)-arizonins C1 and B1 - and 100:0 in favor of a cis disubstitution - exploited for synthesizing the unnatural (+)-5- epi-arizonins C1 and B1. All naphthalenes of the present study were derived from the (benzyloxy)methoxynaphthalenediol 19. It resulted from a Diels-Alder reaction of the aryne 17a with the siloxyfuran 18a. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
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