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Charge transport and electronic transition properties of a series of newly designed anthracene-based non-doped blue emitters were investigated by density functional theory calculations. For a highly efficient non-doped device, Cz3PhAn-based emitters were designed to suppress the hole and electron reorganization energies required for structural relaxation with respect to the changes of charged states. As a result, the hole hopping rates of triphenylamine (TPA) and phenylbenzimidazole (PBI) substituted Cz3PhAn derivatives (1, 4, and 5–7) were tremendously enhanced as compared to that of Cz3PhAn due to the suppression of the reorganization energy of holes, λh. Moreover, 1 and 4 emitters showed almost identical hopping rates of holes and electrons, which can possibly lead to a perfect charge balance and high efficiency. The photo-physical properties showed that the emission energy of all 1–10 emitters is in 439–473 nm range. It is expected that our rational design strategy can help develop non-doped blue fluorescent emitters for high efficiency.

We report a new series of low band gap (LBG) polymers (P1-P4), in which para or meta- alkoxyphenylthiophene (APTh) substituted benzodithiophene and 2,5-ethylhexyl-3,6-bis(5-bromothiophen-2-yl)pyrrolo[3,4-c]-pyrrole-1,4-dione or 2-ethylhexyl-4,6-dibromo-3-fluorothieno[3,4-b]thiophene-2-carboxylate are key repeating units. All the polymers showed broad absorption profiles over 900 nm with reduced optical band gaps (E g opt ). Interestingly, the straightforward modification (exchanging the topology of alkoxy side chain on phenyl group of APTh in donor unit) brought considerable changes in photophysical and photovoltaic properties of new polymers. In particular, meta-substituted polymers (P2, P4) showed reduced E g opt (1.26, 1.41 eV), deep highest occupied molecular orbitals (HOMOs) (-5.23, -5.28 eV) than para-substituted polymers P1, P3 (E g opt =1.33, 1.44 eV; HOMOs=-5.19, -5.20 eV). Furthermore, the optimized P2 and P4 based devices delivered an enhanced power conversion efficiency (PCE) of 4.39 and 4.33%, with open-circuit voltage (V oc ) of 0.71 and 0.79 V, respectively, which are higher than P1 (PCE of 2.95 with V oc of 0.65) and P3 (PCE of 2.33% with V oc of 0.69 V) based devices.

We report an efficient and highly enantioselective hydroboration of aliphatic 1,1-disubstituted alkenes with pinacolborane using a phosphine-Cu catalyst. The method allows facile preparation of enantiomerically enriched β-chiral alkyl pinacolboronates from a range of 1,1-disubstituted alkenes with high enantioselectivity up to 99% ee. Unprecedented enantiodiscrimination between the geminal alkyl substituents was observed with functional group compatibility in the hydroboration. Furthermore, a catalyst loading as low as 1 mol % furnished the desired product without a decrease in yield or selectivity, demonstrating its efficiency in gram scale synthesis.

Highly ordered mesoporous CdxZn1–xS materials were obtained via a simple nanoreplication method using a mesoporous silica template with a 3-D bicontinuous cubic Ia3d mesostructure. Combined analyses using X-ray diffraction, N2 sorption, electron microscopy, and diffuse reflectance UV–visible spectroscopy revealed that the ordered mesoporous ternary compound semiconductor materials exhibited well-developed crystalline frameworks, high surface areas of 80–120 m2g–1, uniform mesopore sizes of about 20 nm, ordered arrangement of mesopores, and outstanding visible light absorption properties. Photocatalytic activities were investigated by degradation of methylene blue and rhodamine B under visible light over the mesoporous CdxZn1–xS materials. Due to the high surface area and outstanding light absorption properties, the ordered mesoporous CdxZn1–xS exhibited excellent photocatalytic performances for the degradation of methylene blue and rhodamine B. This study indicates a potential application of the mesoporou...

Through copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reactions, new pyrene-appended triazole- and triazolium-based fluorescent probes have been synthesized and their binding capabilities for anion recognition were investigated. The probes showed different fluorescence behavior in response to fluoride (F − ) ions. The probe bearing a triazolium moiety, displayed a high selectivity towards F − ions via C H⋯F − hydrogen bonding interaction and de-protonation that was accompanied by fluorescence “turn-on”. Further, the experimental observations were well supported by 1 H NMR spectroscopy and density functional theory (DFT) calculations.

A Cu-catalyzed highly Z-stereoselective hydroboration of alkynes with 1,8-naphthalenediaminatoborane (HB(dan)) is developed. DPEphos (bis[(2-diphenylphosphino)phenyl]ether)-ligated Cu catalysts produced alkenylboron compounds from terminal alkynes with excellent Z-stereoselectivity. In contrast, using a SIPr-CuCl complex as the precatalyst exclusively produced E-hydroboration products at mild conditions. Both catalytic procedures form alkenylboron products stereocomplementary to each other, constituting stereodivergent hydroboration of alkynes through Cu catalysis. Deuterium labeling and isomerization studies support the Z-selective hydroboration via trans-addition of the boron reagent to terminal alkynes as opposed to precedent noble-metal-catalyzed trans-hydroborations.

In order to establish the correlation between intramolecular non-covalent interactions in the polymer backbone and the position/nature of alkoxy side chains in electron rich unit, two new series of low band gap polymers ( P1 – P4 ; P5 – P8 ) were synthesized. We observed significant changes in photophysical properties upon changing the position and nature of the alkoxy side chain with respect to their intramolecular non-covalent interactions in the backbone, which are reflected in their field-effect transistors mobilities and photovoltaic properties. The Uv–Vis spectra of polymers containing a thieno[3,4- c ]pyrrole-4,6-dione unit shows a vibronic shoulder, and the intensity of vibronic shoulder varies upon changing the position and nature of alkoxy side chain, in contrast, this type of absorption shoulder was not observed in polymer series containing a benzo[ c ][1,2,5]-thiadiazole moiety. In the thieno[3,4 -c ]pyrrole-4,6-dione series, a maximum power conversion efficiency of 4.19% with an open-circuit voltage of 0.91 V was noted. The power conversion efficiency of a benzo[ c ][1,2,5]-thiadiazole containing polymers was improved upon addition of 1,8-diiodooctane with maximum of 5.26% being recorded for polymer solar cells.

Calix[n]triazoles are developed as new derivatives in the calixarene family. Calixtriazole compounds 2–4 are synthesized using an iterative convergent strategy including an inter-/intramolecular copper(I)-catalyzed azide–alkyne cycloaddition reaction. Solid-state structures are clearly refined to give 1,2-alternate and partial cone conformations for calix[4]triazole and calix[5]triazole, respectively. Theoretical studies based on density functional theory (DFT) calculations indicated that intermolecular interactions are crucial in determining the conformers of the crystals, and the most stable conformers of calix[4]triazole, calix[5]triazole, and calix[6]triazole in the monomeric forms are 1,3-alternate, 1,3-alternate, and 1,3,5-alternate, respectively.

The detailed reaction mechanism for the borylation of internal aryl alkynes catalyzed by copper(I) boryl complexes was studied by experiments and density functional theory (DFT) calculations. The calculated results indicate that the Cu(I)-catalyzed borylation occurs through Ph–C≡C–R insertion into the Cu–B bond to give the α- and β-borylalkyl intermediates. Among the various substituent groups (Me, Et, i-Pr, t-Bu, 1,1-Et2Pr, and Cum) at the R position, internal aryl alkynes having substituent groups less bulky than an aryl group converted to β-borylated products, whereas those having substituent groups bulkier than an aryl group converted to α-borylated products with high regio- and stereoselectivity.

A series of cationic N-heterocyclic carbene (NHC) precursors that can be utilized as fluorescent chemosensors for carbon dioxide capture were investigated by density functional theory (DFT) calculations. Activation energy barriers for the reactions of the cationic NHC precursors and hydrogen carbonate (HCO3(-)) based on intrinsic reaction coordinate (IRC) profiles as well as proton affinity of the precursors were compared. The calculated proton affinity of 1-ethyl-3-methylimidazol-2-yliene was in good agreement with experimental one within the margin of error. We clarified main factors to lower the activation energy barrier based on the correlation among the number of N-heterocyclic functional group, aromatic ring size, and structural characteristics for the candidate compounds. On the basis of the results, it was verified that some of our model systems spontaneously generate NHCs without any specific catalyst.

In the present paper, density functional theory calculations have been implemented by using Dmol3 to study the electronic band structures of β-graphyne nanotubes (βGyNTs) and γ-graphyne nanotubes (γGyNTs). Our results found different GyNTs show diverse electronic band structures. All βGyNTs have quite small band gaps without any correlation with tube size. Meanwhile, γGyNTs, no matter zigzag or armchair, exhibit semiconductor characteristics with oscillatory band gap ranging from 0.48 eV to 1.20 eV. Furthermore, based on the variation of band gap, both zigzag and armchair γGyNTs can be divided into two subgroups: 2m and 2m + 1 where n is a positive integer, following the order of 2m + 1 > 2m.

Sn-porphyrin networks were engineered on the surface of a thin layer chromatography (TLC) plate via Sonogashira coupling of the Sn-porphyrin building block and 1,4-diiodobenzene. The Sn-porphyrin film showed a strong Soret band absorption at 422 nm, emission at 600-630 nm, and excellent sensing performance toward nitrophenols in water.

In the present study, we report the solvent controlled selectivity of cyanide. A newly synthesized bis-pyrene derivative 1 exhibited large “off–on” fluorescence enhancement with fluoride and cyanide in CH3CN-DMSO (99:1, v/v), which was accompanied by unique colorimetric changes. Likewise, in CH3CN-DMSO-EtOH (98:1:1, v/v) or CH3CN-DMSO-H2O (94:1:5, v/v), selective fluorescence enhancement with cyanide was observed among the various anions, which was attributed to a favourable interaction between the fluoride ion with ethanol or water. The binding modes, UV absorption and fluorescence changes of 1 upon CN− binding are also explained by DFT calculations. Probe 1 was successfully applied for imaging cyanide in the HeLa cells. Finally, anion-activated CO2 sensing via colour and fluorescence changes is demonstrated using chemosensor 1.

We demonstrate that the imidazole-based ligand 1 efficiently produces a coordination polymer gel by simple mixing with Co2+ ion. When the molar ratio of CoCl2 to ligand 1 was less < 1, a red sol was obtained, indicating the formation of an octahedral (Oh) complex species as occurs with Co(NO3)2. In contrast to G1, when the amount of CoCl2 employed was more than 1 equiv., the color of the gel changed from red to blue (G2), indicating the formation of mainly a tetrahedral (Td) complex species. The ionochromic and the piezochromic effects of imidazole-based suprmolecular gel with Co2+ were investigated. These effects of supramolecular gel were controlled by various anions of cobalt, which are due to coordination geometric change of gels. Interestingly, the ionochromic and piezochromic effects of G1 act as AND and OR logic gates in the solid and the gel state.

Three Y-shape organic dyes, (Z)-3-(5-(3,5-bis(4-(9H-carbazol-9-yl)styryl)-4-methoxyphenyl)thiophen-2-yl)-2-cyanoacrylic acid (OD-1), (Z)-3-(5′-(3,5-bis(4-(9H-carbazol-9-yl)styryl)-4-methoxyphenyl)-2,2′-bithiophen-5-yl)-2-cyanoacrylic acid (OD-2) and (Z)-3-(5′-(3,5-bis(4-(9H-carbazol-9-yl)styryl)-4-methoxyphenyl)-3,4′-4″-trithiophenyl-5-yl)-2-cyanoacrylic acid (OD-3) were synthesized and used as sensitizers in nanocrystalline dye-sensitized solar cells (DSSCs). The introduction of the bis(carbazolylstyryl) units as an electron donor group and oligothiophene units as a both electron donors and π-spacers increased the conjugation length of the sensitizers and thus improved their molar absorption coefficient and light harvesting efficiency. DSSCs with the configuration of SnO2:F/TiO2/organic dye/liquid electrolyte/Pt devices were fabricated using these OD-1, OD-2 and OD-3 as a sensitizers. Among the devices, the DSSC composed of OD-3 exhibited highest power conversion efficiency of 3.03% under AM1.5G (100 mW cm−2).

A new sensor for the fluorescent and colorimetric detection of CO(2) is described. The system utilizes fluoride to activate a tetrapropyl benzobisimidazolium salt and operates in the absence of an exogenous base. On the basis of spectroscopic and theoretical analyses, the mode of action of the present system is ascribed to the fluoride-induced formation of an N-heterocyclic carbene intermediate that reacts with CO(2) to form an imidazolium carboxylate.

A Cu-catalyzed highly Z-stereoselective hydroboration of alkynes with 1,8-naphthalenediaminatoborane (HB(dan)) is developed. DPEphos (bis[(2-diphenylphosphino)phenyl]ether)-ligated Cu catalysts produced alkenylboron compounds from terminal alkynes with excellent Z-stereoselectivity. In contrast, using a SIPr–CuCl complex as the precatalyst exclusively produced E-hydroboration products at mild conditions. Both catalytic procedures form alkenylboron products stereocomplementary to each other, constituting stereodivergent hydroboration of alkynes through Cu catalysis. Deuterium labeling and isomerization studies support the Z-selective hydroboration via trans-addition of the boron reagent to terminal alkynes as opposed to precedent noble-metal-catalyzed trans-hydroborations.

Crystalline coordination polymers are a newer class of organic–inorganic hybrid nanomaterials created by infinitely extending metal–ligand coordination interactions. These polymers show promise in a broad range of applications, including gas storage, molecular sieves, ion exchange, sensing, magnetism, and catalysis. [1, 2] Recently, a rational-design strategy for supramolecular gels based on the concept of coordination polymers is attracting interest. [3–6] In particular, recent studies have demonstrated that simple bridging organic units can facilitate the formation of coordination polymer gels in the absence of auxiliary moieties (e.g., urea, sugar, cholesterol, long alkyl chains), offering new possibilities to produce functional soft materials from structurally

Bis-pyrene derivative 1, bearing two pyrene and pyridine groups, was synthesized as a ratiometric fluorescent chemosensor for Ag(+) in aqueous solution. Fluorescent chemosensor 1 displayed a selective ratiometric change with Ag(+), which was attributed to the excimer-monomer emissions of pyrenes. A mechanism for the binding mode was proposed based on fluorescence changes, NMR experiments, and theoretical calculations.

A new tetranaphthoimidazolium receptor was synthesized and reported to be a selective fluorescent chemosensor for phytate, myo-inositol hexakisphosphate (IP6). In a 100% aqueous solution at pH 7.4, chemosensor 1 showed a selective fluorescence enhancement for IP6 over IP3, phosphates, pyrophosphates, AMP, ADP and ATP. An excimer emission at 465 nm linearly increases in the range of 300 nM to 1 μM with a detection limit of 2.28 × 10(-7) M. In addition, first live cell imaging of IP6 has been demonstrated by using a synthetic receptor.

We have developed a unique binaphthyl-pyrene system 1, whose dihedral angle is reversibly modulated by the addition of Zn(2+). Dihedral angle changes in this system were monitored by using circular dichroism (CD) and by an observed "off-on" fluorescence enhancement in aqueous solution. Owing to these changes, the presence of biologically important Zn(2+) ions in samples can be readily monitored by employing CD and fluorescence spectroscopy. Finally, the experimental observations made in this effort are supported by the results of quantum mechanical calculations.

A nucleotide is composed of a nucleobase, a five-carbon sugar, and phosphate groups. Recognition of these three sites can provide useful information for the development of selective fluorescent receptors for a specific nucleotide. In this paper, anthracene derivatives with two imidazolium groups at the 1,8- and 9,10-positions, quaternary ammonium groups, or the boronic acid group were examined for the recognition of nucleotides, such as ATP, GTP, CTP, TTP, UTP, ADP, and AMP, via fluorescence changes. The anthracene group provides the interaction between the bases of the nucleotides. The imidazolium and quaternary ammonium groups induce hydrogen bonding interactions with the phosphate groups of the nucleotides. The boronic acid group can interact with the ribose of the nucleotides.

In this study, a novel fluorescent cyclic benzobisimidazolium derivative was designed and prepared for the selective recognition of HSO4−. Pre-organization, neutral C–H hydrogen bonds and charge interactions play key roles in recognizing HSO4− in aqueous solution. Spectroscopic studies, including UV-vis and fluorescence, showed that this cyclic receptor exhibited high selectivity in response to HSO4−. X-Ray crystal data, NMR data and theoretical calculations are presented to explain its unique binding mode.

Naphthoimidazolium groups can form unique ionic hydrogen bonds with anions as imidazolium moieties, and in addition, they are fluorescent, so no further elaborative synthesis is needed to introduce a fluorescent group. In this paper, three naphthoimidazolium derivatives were synthesized and studied for the recognition of nucleotides. Compound 1 composed of a single naphthoimidazolium group and quaternary ammonium group did not show any significant fluorescent changes with various anions and nucleotides, such as ATP, GTP, CTP, TTP, UTP, ADP and AMP. A tripodal compound 3 bearing three naphthoimidazolium groups and three quaternary ammonium groups, respectively, showed large fluorescence enhancements with UTP, CTP and TTP and moderate fluorescence enhancements with ATP and pyrophosphate and a fluorescence quenching effect with GTP. On the other hand, compound 2 bearing two naphthoimidazolium groups and two quaternary ammonium groups displayed a selective fluorescence enhancement with ATP and a selective fluorescence quenching effect with GTP in 100% aqueous solution.

Polydiacetylenes (PDAs), a family of conjugated polymers, are known to show stimulus-induced apparent blue-to-red transitions, which have led to the development of a variety of PDA-based chemosensors. However, in most cases, recognition sites were introduced at the terminal ends of PDAs, therefore, recognition processes on the surface of PDAs have been the primary stimulations to induce blue to red colorimetric changes. In this study, we reported that diverse colorimetric changes can be observed for PDA based sensors in which penetration of cationic surfactant into PDAs bearing benzoic acid groups can cause not only the typical blue to red change but also blue to violet, blue to yellow or blue to orange color change. We systematically demonstrated that these novel findings can be used effectively to discriminate different cationic surfactants by using three different PDAs. Furthermore, theoretical calculations and transmission electron microscope (TEM) images also confirm these unique colorimetric changes. These results suggest a new direction in which to design colorimetric sensors based on PDA polymers.