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Metal–organic frameworks: The solvothermal reaction of Zn2+ ions and bis‐ (pyrazolyl)naphthalene diimide readily affords strongly adhering, electroactive metal–organic framework thin films on conductive glass substrates (see picture). Electrochemical cycling of these films followed by in situ UV/Vis spectroscopy reveals striking multicolored electrochromic responses. [ABSTRACT FROM AUTHOR]

Understanding the roles of various parameters in orchestrating the preferential chiral molecular organization in supramolecular self-assembly processes is of great significance in designing novel molecular functional systems. Cyclic dipeptide (CDP) chiral auxiliary-functionalized naphthalenediimides (NCDPs 1- 6) have been prepared and their chiral self-assembly properties have been investigated. Detailed photophysical and circular dichroism (CD) studies have unveiled the crucial role of the solvent in the chiral aggregation of these NCDPs. NCDPs 1- 3 form supramolecular helical assemblies and exhibit remarkable chiroptical switching behaviour ( M- to P-type) depending on the solvent composition of HFIP and DMSO. The strong influence of solvent composition on the supramolecular chirality of NCDPs has been further corroborated by concentration and solid-state thin-film CD studies. The chiroptical switching between supramolecular aggregates of opposite helicity ( M and P) has been found to be reversible, and can be achieved through cycles of solvent removal and redissolution in solvent mixtures of specific composition. The control molecular systems (NCDPs 4- 6), with an achiral or D-isomer second amino acid in the CDP auxiliary, did not show chiral aggregation properties. The substantial roles of hydrogen bonding and π-π interactions in the assembly of the NCDPs have been validated through nuclear magnetic resonance (NMR), photophysical, and computational studies. Quantum chemical calculations at the ab initio, semiempirical, and density functional theory levels have been performed on model systems to understand the stabilities of the right ( P-) and left ( M-) handed helical supramolecular assemblies and the nature of the intermolecular interactions. This study emphasizes the role of CDP chiral auxiliaries on the solvent-induced helical assembly and reversible chiroptical switching of naphthalenediimides. [ABSTRACT FROM AUTHOR]

Phosphonium salts are widely used in organic synthesis as the precursor of Wittig reagents but highly functionalized phosphonium salts are not readily available. We have developed a sequence of propargyl-allenyl isomerizations and electrocyclizations for the functionalization of phosphonium salts via simple starting materials, which may provide an efficient one-pot synthesis of polysubstituted vinylbenzenes and naphthalenes. [ABSTRACT FROM AUTHOR]

Three donor-acceptor (D-A) naphthalene diimide copolymers, poly{thieno[3,2-b]thiophene-diyl-alt-N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)}(P1), poly{4,8-dioctyloxybenzo[1,2-b;3,4-b!]dithiophene-diyl-alt-N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)}(P2), and poly{4,8-bis(2-ethylhexyloxy)benzo[1,2-b:4,5-b!]dithiophene-diyl-alt-N,N!-bis(2-octyldodecyl) -naphthalene-1,4,5,8-bis(dicarboximide)}(P3), were synthesized by Stille coupling reaction. All copolymers showed good solubility in common organic solvents with broad absorption region and narrow optical band gap. The electrochemical properties of the polymers can be adjusted by changing the donor segment. P1 showed n-type characteristic while P2 and P3 showed p-type characteristic. All-polymer solar cells using P3HT as the donor and P1 as the acceptor were fabricated and the highest power conversion efficiencies (PCEs) of 0.068% were obtained under the preliminary condition. Moreover, p-type naphthalene diimide copolymers (P2 and P3) based on D-A system were used as donors to fabricate bulk heterojunction polymer solar cells (BHJ, PSCs) for the first time, and the maximum power conversion efficiencies PCEs were about 0.021 and 0.017%, respectively. [ABSTRACT FROM AUTHOR]

In this article, we report the synthesis of the naphthalene and cholesterol derivative 2-(cholesterol-n-decanoate)-6-(heptyloxy benzoate) naphthalene (2CD6HBN) liquid crystal (LC) having chiral nematic (N*) mesophase. The synthesised mesophase has been characterised using polarising optical microscopy (POM) and differential scanning calorimetric (DSC) study. The presence of the rigid and less polarisable cores causes a higher N*-Iso transition temperature. The relaxation phenomenon of the present LC sample was analysed by the dielectric relaxation spectroscopic study. The dielectric properties, electrical conductivity and the relaxation time were observed as a function of the temperature. The relaxation time follows the first-order exponential decay–type equation. The properties of the LC sample have also been correlated with the structure of the compound. [ABSTRACT FROM AUTHOR]

Ein Ferrocenderivat mit direkt angeknüpften Naphthalindiimid ‐ Einheiten kann über Redoxprozesse zwischen Strukturen mit gestapelten und nichtgestapelten Naphthalindiimiden geschaltet werden. Konformation und elektronische Struktur der Naphthalindiimide wurden für jeden Elektronentransferzustand quantitativ erfasst. Der Komposit zeigt das Verhalten eines n ‐ Halbleiters. [ABSTRACT FROM AUTHOR]

The copper(I)-catalyzed domino reactions between the easily accessible 3-(2-halobenzyl)pentane-2,4-diones and β-keto esters, malonates and cyanoacetates afford trisubstituted naphthoates and naphthonitriles with yields up to 85%. [ABSTRACT FROM AUTHOR]

Photolysis reaction of dibenzo[ a, d]cycloheptene dimer 3 provides three dibenzo[ a, d]cycloheptyl dimers 4, 5 and 6 under different irradiation conditions via the intramolecular degradative cyclodimerization. A tetracyclic benzo[4,5]cyclohepta[1,2,3- de]naphthalene core is also synthesized. [ABSTRACT FROM AUTHOR]

The synthesis of new 3H-naphtho[2,1-b]pyran dyes substituted at position 8 of the naphthalene ring by either a stilbazolium or an 4-ethenyl-quinolinium group and their photochemical properties are described. In non-polar media the naphthopyran–stilbazolium conjugates do not show any photochromic response while the formation of the ring opened species is promoted in strong polar media. Additional investigations of the new dyes within the pores of mesoporous MCM 41 particles showed a significant enhancement of the photochromism compared with that in solution. The generation of the ring-opened species upon irradiation with UV-light is accompanied by a decrease of the fluorescence intensity, which could be recovered by illumination with visible light. [ABSTRACT FROM AUTHOR]

A chromophoric system (E)-2-(4-(naphthalen-1-yldiazenyl)phenyl)acetic acid incorporated onto a nature friendly biopolymeric core material, lignin (technical lignin, lignin sulphonic acid M.W. 52,400), and the photo responsive behavior of the product was investigated. The product was characterized by UV-visible, fluorescence, Fourier transform infrared, and nuclear magnetic resonance spectroscopic methods. The results of the studies show that the incorporation of the chromophoric system on to the lignin core enhanced the light absorption and light stabilization properties of the chromophoric system. The trans-cis photoisomerization and the reverse cis-trans thermal conversions were also assisted by the lignin core. The remarkable stability on irradiation shows that this is a novel photoresponsive system with excellent light fastening properties which would find application in coating materials, dyes, paints, inks, and many more. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Two acceptor-acceptor dyads have been synthesized featuring a flavin moiety and a naphthalenediimide (NDI) unit. The NDI unit is linked to the flavin through a short spacer group via either the N(3) or N(10) positions of the flavin. We have investigated the UV-Vis and redox properties of these multi-electron accepting systems which indicate that these materials display the collective properties of their component systems. Fluorescence spectroscopy measurements have revealed that their emission properties are dominated by the flavin unit. [ABSTRACT FROM AUTHOR]

New double (fluorescent and spin) sensor molecules containing 4-amino substituted 1,8-naphthalimide as a fluorophore and a sterically hindered amine (pre-nitroxide) or pyrroline nitroxide as a quencher and radical capturing moiety were synthesized. All sensors were substituted with a diethylaminoethyl side-chain to increase the water solubility. Steady state fluorescence properties of these compounds and their responses to ROS in vitro are reported with perspectives of plant physiology use in vivo. [ABSTRACT FROM AUTHOR]

Modification of sodium lignosulfonate (SLS) via combined oxidation- sulfomethylation was employed to prepare concrete superplasticizer. It was found that the oxidation of SLS by peroxyacetic acid facilitated the subsequent sulfomethylation. After modification, both the molecular weight and sulfo group content were significantly increased, and thus the performance of SLS as water reducer was improved. With the water to cement ratio at 0.4 and 0.3% (w/w) modified SLS, the fluidity of cement paste could reach 185 mm, which was 15% higher than that with unmodified SLS. It was also comparable to the performance of commercial naphthalene superplasticizer under the same conditions. [ABSTRACT FROM AUTHOR]

The chemical preparation and crystal structure of styphnic acid and naphthalene-1,4-diol (1:1) (I) have been reported. The compound crystallizes in the orthorhombic system in space group Pnma and cell parameters a = 6.6712(2), b = 16.8267(7), e = 13.6450(5) Å and V = 1531.71(10) ų, and Z = 4. Crystal structure has been determined and refined to R = 0.0576. The crystal structure of I, the asymmetric unit, contains C6H2N3O7, C10H7O, and it is a half portion of both styphnic acid and naphthalene-1,4-diol. The O1-H1⋯O2 intramolecular hydrogen bond was found between the O-H and a nitro group in the styphnic acid unit. [ABSTRACT FROM AUTHOR]

Iron catalyzes the oxidative [2+2+2] annulation of an ­arylmagnesium compound with two molecules of an internal alkyne via C–H bond activation at 0 °C to produce polysubstituted naphthalene. [ABSTRACT FROM AUTHOR]

A novel and efficient access to 2-(argio(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1 H-pyrazol-4-yl)methyl)-3-hydroxynaphthalene-1,4-dione derivatives from readily available substrates in neat water is described with aid of microwave irradiation. The results of our study provide a green, simple and practical one-pot approach to the synthesis of 3-hydroxynaphthalene-1,4-dione analogs in excellent yields without further purification. [ABSTRACT FROM AUTHOR]

Highly regioselective di-tert-amylation of naphthalene using different alcohols can be achieved over a H-mordenite (HM) zeolite. For example, the tert-amylation of naphthalene using tert-amyl alcohol in cyclohexane over HM (Si/Al = 10) zeolite has been optimised to give a 70% yield of 2,6-dialkylnaphthalenes, of which 2,6-di-tert-amylnaphthalene was produced in 46% yield along with 2-tert-amyl-6-tert-butylnaphthalene (23%) and 2,6-di-tert-butylnaphthalene (1%). This has been achieved by varying the reaction time, temperature, pressure and amounts of tert-amyl alcohol and zeolite. No 2,7-dialkylnaphthalenes were seen under the conditions tried. The zeolites can be easily regenerated by heating and then reused. [ABSTRACT FROM AUTHOR]

The first total synthesis of malvone A (1) is presented in seven steps along with a nine-step formal synthesis of boryquinone (2) and an eleven-step formal synthesis of hybocarpone (3). The overall strategy, which accesses compounds 7-12 for the first time, employs an easily constructed α-tetralone, and it has significant implications for synthesis of the naphthoquinone portion of β-rubromycin (4) as well as a host of other unsymmetrical and differentially protected naphthoquinones. [ABSTRACT FROM AUTHOR]

In the presence of PtCl2/CO catalyst, 2-alkenyl-(1′-hydroxyl-4-en-2-ynyl)benzenes undergo a tandem electrophilic 6-exo-dig cyclization-Nazarov cyclization sequence to give 1H-cyclopenta[a]naphthalenes efficiently and regioselectively. [ABSTRACT FROM AUTHOR]

Perylene diimides (PDIs) and naphthalene diimides (NDIs) can be efficiently aminated with primary or secondary amines under mild conditions using Cu(ii) salts as catalysts and air as an oxidant. Depending on the substrate and the amine, yields over 80% can be obtained by simply stirring the reaction mixture at room temperature for one hour. [ABSTRACT FROM AUTHOR]

Tandem reaction of 2-alkynylbenzonitriles with a Reformatsky reagent turned out to be a novel and efficient approach toward 1-aminonaphthalene-2-carboxylates. Interestingly, with 2-(3-hydroxyprop-1-ynyl)benzonitriles as the substrates, a more sophisticated cascade process occurred to give 9-aminonaphtho[2,3-c]furan-1(3H)-ones in good yields. By using this tandem reaction as a key step, a concise and versatile synthetic strategy for the total synthesis of arylnaphthalene lactone lignans has been developed. [ABSTRACT FROM AUTHOR]

A fluorescent probe for selective detection of mercury based on an azobenzene derivative bearing naphthalene units has been synthesised and its cation recognition abilities examined by UV-Vis and fluorescence spectroscopy. The fluorescent probe exhibits a highly selective response of fluorescence enhancement toward mercury in DMF aqueous media (DMF: H2O, v/v = 1:1). [ABSTRACT FROM AUTHOR]

A formal [2 + 2 + 2] cycloaddition of a 1,6-enyne with 2-bromophenylboronic acid has been realized to construct a multi-substituted dihydronaphthalene scaffold, in which the direct reductive elimination mechanism of aryl-Rh(III)-Csp³ species has been established to form an aryl-Csp³ bond. [ABSTRACT FROM AUTHOR]

Like beautiful magic, the novel synthetic method described in this paper was used to prepare osmanaphthalynes, osmaanthracyne, and osmaphenanthryne. Under this kind of "magic", the dragons (which represent the osmium compounds) transform into different shapes. The colors of the dragons correspond to the colors of the compounds reported. More information can be found in the Communication by J. Yin, S. H. Liu et al. on page 14891. [ABSTRACT FROM AUTHOR]

During this decade, the enantio- and stereoselective synthesis of natural products has been actively explored in the author's laboratory. In this account, the author outlines practical syntheses of the polycyclic substructures of two novel structurally formidable antibiotics, namely, the trans-fused octahydronaphthalene moiety of versipelostatins and the A/ B/ C-tricyclic decahydrofluorene moiety of GKK1032s. Both syntheses have been achieved with remarkable regio- and stereoselectivity via intramolecular Diels- Alder reactions using well-designed enantiomeric substrates. [ABSTRACT FROM AUTHOR]