- Unfolding ESIPT in Bis-2,5-(2-benzoxazolyl) Hydroquinone and 2,5-Bis(benzo[d]oxazol-2-yl)-4-methoxyphenol: a Comprehensive Computational Approach
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The photo-physical behaviour of bis-2,5-(2-benzoxazolyl) hydroquinone and 2,5-bis (benzo[d]oxazol-2-yl)-4-methoxyphenol was studied using the Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT). All the possible rotamers were optimized to obtain global minimum optimized structure. The theoretical absorption and emission values of rotamers estimated by using TD-DFT [TD-B3LYP/6–31G(d)] are in good agreement with experimental absorption and emission wavelengths. Based on the absorption values, the contribution of respective rotamer is determined theoretically.
- Jadhav, Manoj M.,Rhyman, Lydia,Ramasami, Ponnadurai,Sekar, Nagaiyan
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- TD-DFT Investigation of 2,5-Bis(2-benzothiazolyl)hydroquinone and 2,5-Bis(benzo[d]thiazol-2-yl)-4-methoxyphenol
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Density functional theory (DFT) and time dependent density functional theory (TD-DFT) calculations of two excited state intramolecular proton transfer (ESIPT) molecules [2,5-bis(2-benzothiazolyl)hydroquinone and 2,5-bis(benzo[d]thiazol-2-yl)-4-methoxyphenol] were performed to study their structural and photo-physical behavior upon excitation. The most stable structure was established by optimizing all possible rotamers. The vertical excitation and emission wavelengths obtained by using TD-DFT show very good correlation with the experimental values. A correlation has been established based on the absorption values to determine the contribution of stable rotamers.
- Jadhav, Manoj M.,Alswaidan, Ibrahim A.,Rhyman, Lydia,Ramasami, Ponnadurai,Sekar, Nagaiyan
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- A heterofunctional ligand approach for the preparation of high connectivity coordination polymers: Combining a "bridge" and "pillar" in one ligand
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Two of the most successful strategies for the preparation of three-dimensional coordination polymers and MOFs are reticular synthesis and pillaring. Here we present a new approach which combines aspects of both of these by employing a heterofunctional dicarboxylic and dipyridyl ligand, 2,5-di(pyridin-4-yl)terephthalic acid (H2L). The reaction of H2L with zinc(ii) produces a non-interpenetrated 3D coordination polymer [ZnL(H2O)]n. This journal is
- Al-Fayaad, Hydar A.,Athukorala Arachchige, Kasun S.,Clegg, Jack K.
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- Tuning J-aggregate Formation and Emission Efficiency in Cationic Diazapentacenium Dyes
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Enhancement of the luminescence efficiency of two new diazapentacenium salts (D1 and D2) of more than 55 for D1 and 22 times for D2) in poor solvents, acetonitrile and/or dichloromethane, was observed and rationalized as formation of emissive J-aggregates. Both compounds displaying 4-n-decylphenyl substituents at the 7,14-carbons and phenyl (D1) or 2,6-difluorophenyl (D2) substituents at the quaternary nitrogen atoms in 5,12-positions have been synthetized in a two-step procedure involving a two-fold Buchwald-Hartwig-type CN cross-coupling and an electrophilic Friedel-Crafts-type cyclization. The optical properties of the dicationic diazapentacenium salts in various solvents and in thin films have been investigated by steady-state and time-resolved absorption and photoluminescence spectroscopies. In thin films and in good solvents, isolated molecules coexist with aggregates. Nonetheless, D1 is seven times more emissive than D2, reflecting a higher J-aggregate contribution in the former.
- Rodrigues, Ana Clara B.,Wetterling, Dario,Scherf, Ullrich,Seixas de Melo, J. Sérgio
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p. 7826 - 7830
(2021/05/07)
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- PREPARING METHOD OF SYNTHESIZING INDACENO DITHIENOTHIOPHENE COMPOUND
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Provided is a manufacturing method of synthesizing an indaseno-dithienothiophene compound using, as a novel starting material, a bis(thieno[3,2-b] thiophen-2-yl)-bismethanone derivative. The manufacturing method of synthesizing the indaseno-dithienothiophene compound has an excellent synthetic yield and improves production efficiency.COPYRIGHT KIPO 2020
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Paragraph 0097; 0101-0102
(2019/12/25)
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- Pd-tBuONO Cocatalyzed Aerobic Indole Synthesis
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A Pd-tBuONO co-catalyzed scalable and practical synthesis of indoles with molecular oxygen as terminal oxidant is developed. Either terminal or internal 2-vinylanilines could be smoothly converted to desired indoles under one general condition. This method has been evaluated in the large scale synthesis of indomethacin and a potential anti-breast cancer drug candidate 1. (Figure presented.).
- Ning, Xiao-Shan,Liang, Xin,Hu, Kang-Fei,Yao, Chuan-Zhi,Qu, Jian-Ping,Kang, Yan-Biao
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supporting information
p. 1590 - 1594
(2018/04/30)
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- Substituent effect on redox potential of terephthalate-based electrode materials for lithium batteries
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The substituent effect on the redox potential of lithium terephthalate was studied using symmetrical dilithium disubstituted-terephthalates incorporating bromo, methoxy and amino groups. All the terephthalate derivatives have been synthesized and evaluated as anode material for lithium-ion batteries. The electrochemical results revealed an increase in the reduction potential in the case of bromo and methoxy groups and almost the same in the case of amino group compared to unmodified dilithium terephthalate. In addition, a very first tendency between the 13C chemical shifts and FTIR signal of the carbonyl and the reduction potential of the studied disubstituted-terephthalates was formulated.
- Lakraychi,Dolhem,Djeda?ni-Pilard,Becuwe
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- A Series of Lanthanide Coordination Polymers Based on Designed Bifunctional 1,4-Bis(imidazol-1-yl)terephthalic Acid Ligand: Structural Diversities, Luminescence, and Magnetic Properties
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On the basis of the designed bifunctional 1,4-bis(imidazol-1-yl)terephthalic acid (H2BTA) ligand, a series of three-dimensional lanthanide coordination polymers, namely, [La2(BTA)1.5(ox)1.5(H2O)3]n (1), [Nd(BTA)(ox)0.5(H2O)]n (2), {[Ln(HBTA)(ox)(H2O)]·xH2O}n (Ln = Pr for 3 (x = 0), Sm for 4 (x = 0), Dy for 5 (x = 1.5), and Eu for 6 (x = 1)), and [Ln(BTA)(SO4)0.5(H2O)]n (Ln = Eu for 7, and Tb for 8) were obtained with the help of oxalate or sulfate ions. On the basis of the binuclear La2 secondary building unit (SBUs), the framework of 1 displays an unprecedented (3,3,4,9)-connected net with the point symbol of (411.55.614.75.8)2(42.5)2(43)2(44.62). While in complex 2, the binuclear Nd2 SBUs are connected by the BTA2- ligands to generate an interestingly (4,10)-connected (412.516.612.75)(46)2 net. Complexes 3-6 are isomorphism and show a 2-fold interpenetrated 4-connected (66)-dia net. Complexes 7 and 8 are isomorphism and show a novel (4,5)-connected (44.62)(44.66) net. Photoluminescence investigations show that 2 is a good near-infrared luminescent material, and 4 is a rarely reported single component white light emitting material. Complexes 6 and 7 show typically red emission, while complex 8 shows typically green emission, which can be used as a red or green emitting phosphor. Moreover, the luminescent lifetimes and quantum yields of the titled complexes were investigated. The magnetic susceptibility data of 2 indicated there are antiferromagnetic interactions between the NdIII ions.
- Zhang, Xiu-Tang,Fan, Li-Ming,Fan, Wei-Liu,Li, Bin,Liu, Guang-Zeng,Liu, Xin-Zheng,Zhao, Xian
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p. 3993 - 4004
(2016/07/16)
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- Synthesis of dilactone bridged terphenyls with crankshaft architectures
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Three highly fluorescent dilactone bridged terphenyls with crankshaft architectures have been synthesized. This general class of compounds is relatively unexplored. These compounds have been characterized by fluorescence and UV-vis spectroscopy. For all three compounds, a direct correlation between the rigidity of the terphenyl system and the strength of absorption and emission of light has been observed. Preliminary studies have indicated that compounds with this architecture have the potential to be useful as pH-driven molecular switches and/or sensors with instant fluorescence attenuation at high pH values.
- Dressler, Justin J.,Miller, Sarah A.,Meeuwsen, Brian T.,Riel, Asia Marie S.,Dahl, Bart J.
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p. 283 - 292
(2015/02/02)
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- Strong solid emission and mechanofluorochromism of carbazole-based terephthalate derivatives adjusted by alkyl chains
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Three 2,5-dialkylcarbazole-substituted terephthalate derivatives, in which carbazole and ethoxylcarbonyl groups are used as electron-donating and -accepting moieties, respectively, were synthesized. Owing to the presence of steric hindrance between ethoxylcarbonyl and carbazole groups, three compounds show intense blue fluorescence in both solution and the solid state. The fluorescence quantum yields of compounds with octyl and hexadecyl groups in the solid state exceed 95%. Single-crystal structures of three compounds were obtained and used to interpret the strong emission in the solid state. More interestingly, three compounds exhibited alkyl length-dependent mechanofluorochromism. The compound with ethyl groups exhibited the largest spectral shift under force stimuli, but that with a hexadecyl moiety did not change its emission color after grinding. Because of strong fluorescence in solution and the solid state, we believe that they can be used as luminescent materials and sensors. This journal is
- Xue, Pengchong,Sun, Jiabao,Chen, Peng,Gong, Peng,Yao, Boqi,Zhang, Zhenqi,Qian, Chong,Lu, Ran
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p. 4086 - 4092
(2015/04/27)
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- Two BN isosteres of anthracene: Synthesis and characterization
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The synthesis of two parental BN anthracenes, 1 and 2, was developed, and their electronic structure and reactivity behavior were characterized in direct comparison with all-carbon anthracene. Gas-phase UV-photoelecton spectroscopy studies revealed the following HOMO energy trend: anthracene, -7.4 eV; BN anthracene 1, -7.7 eV; bis-BN anthracene 2, -8.0 eV. The λmax of the lower energy band in the UV-vis absorption spectrum is as follows: anthracene, 356 nm; BN anthracene 1, 359 nm; bis-BN anthracene 2, 357 nm. Thus, although the HOMO is stabilized with increasing BN incorporation, the HOMO-LUMO band gap remains unchanged across the anthracene series. The emission λmax values for the three investigated anthracene compounds are at 403 nm. The pKa values of the N-H proton for BN anthracene 1 and bis-BN anthracene 2 were determined to be approximately 26. BN anthracenes 1 and 2 do not undergo heat- or light-induced cycloaddition reactions or Friedel-Crafts acylations. Electrophilic bromination of BN anthracene 1 with Br2, however, occurs regioselectively at the 9-position. The reactivity behavior and regioselectivity of bromination of BN anthracenes are consistent with the electronic structure of these compounds; i.e., (1) the lower HOMO energy levels for BN anthracenes stabilize the molecules against cycloaddition and Friedel-Crafts reactions, and (2) the HOMO orbital coefficients are consistent with the observed bromination regioselectivity. Overall, this work demonstrates that BN/CC isosterism can be used as a molecular design strategy to stabilize the HOMO of acene-type structures while the optical band gap is maintained.
- Ishibashi, Jacob S.A.,Marshall, Jonathan L.,Mazire, Audrey,Lovinger, Gabriel J.,Li, Bo,Zakharov, Lev N.,Dargelos, Alain,Graciaa, Alain,Chrostowska, Anna,Liu, Shih-Yuan
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supporting information
p. 15414 - 15421
(2015/01/08)
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- 4,9-dihydro-4,4,9,9-tetrahexyl- s -indaceno[1,2- b:5,6- b ′]dithiophene as a π-spacer of donor-π-acceptor dye and its photovoltaic performance with liquid and solid-state dye-sensitized solar cells
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A new D-π-A organic dye, LC-5, containing 4,9-dihydro-4,4,9,9- tetrahexyl-s-indaceno[1,2-b:5,6-b′]-dithiophene as a novel π-conjugated spacer has been synthesized and tested as a sensitizer in dye-sensitized solar cells (DSC). Volatile and ionic liquid electrolytes have been used in conjunction with the synthesized dye, and the electrolyte influence on the photovoltaic performance of DSCs was investigated. A detailed investigation, including transient photocurrent/photovoltage decay measurements and electrochemical impedance spectroscopy data, provide important conclusions about the influence of electrolytes on the photovoltaic parameters.
- Cai, Liping,Moehl, Thomas,Moon, Soo-Jin,Decoppet, Jean-David,Humphry-Baker, Robin,Xue, Zhaosheng,Bin, Liu,Zakeeruddin, Shaik M,Graetzel, Michael
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supporting information
p. 106 - 109
(2014/01/23)
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- New photosensitizer with phenylenebisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units for dye-sensitized solar cells
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A new low band gap photosensitizer, D, which contains 2,2′-(1,4- phenylene) bisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units at both sides was synthesized. The two carboxyls attached to the 2,5-positions of the phenylene ring act as anchoring groups. Dye D was soluble in common organic solvents, showed long-wavelength absorption maximum at 620-636 nm and optical band gap of 1.72 eV. The electrochemical parameters, i.e. the highest occupied molecular orbital (HOMO) (-5.1 eV) and the lowest unoccupied molecular orbital (LUMO) (-3.3 eV) energy levels of D show that this dye is suitable as molecular sensitizer. The quasi solid state dye-sensitized solar cell (DSSC) based on D shows a short circuit current (Jsc) of 9.95 mA/cm2, an open circuit voltage (Voc) of 0.70 V, and a fill factor (FF) of 0.64 corresponding to an overall power conversion efficiency (PCE) of 4.40% under 100 mW/cm2 irradiation. The overall PCE has been further improved to 5.52% when diphenylphosphinic acid (DPPA) coadsorbent is incorporated into the D solution. This increased PCE has been attributed to the enhancement in the electron lifetime and reduced recombination of injected electrons with the iodide ions present in the electrolyte with the use of DPPA as coadsorbant. The electrochemical impedance spectroscopy (EIS) results indicated that the augment ascribes to inhibited interfacial charge recombination between the conduction band electrons and the tri-iodide ions in the electrolyte.
- Mikroyannidis,Suresh,Roy,Sharma
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p. 5616 - 5623
(2011/06/26)
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- DIINDENOTHIOPHENE DERIVATIVES AND USE THEREOF
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A diindenothiophene derivative of the following formula (1) is disclosed: wherein each of G1, G2, G3 and G4 is independently an unsubstituted or substituted C6-C40-aromatic group or a C1-C40-aliphatic group; A is an electron-withdrawing group; and D is an electron-donating group. The inventive diindenothiophene derivatives can be used in a dye-sensitized solar cell.
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Page/Page column 4-8
(2010/07/08)
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- Low-bandgap conjugated polymer for high efficient photovoltaic applications
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We investigate the morphological and performance of organic photovoltaics based on blended films of alternating poly(thiophene-phenylene-thiophene) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). The resulting fine-scale phase separation leads to enhanced performance and the highest power efficiency (6.4% under AM 1.5G (100 mW cm-2)) when we use solvent annealing process.
- Chen, Yi-Chun,Yu, Chao-Ying,Fan, Yu-Ling,Hung, Ling-I.,Chen, Chih-Ping,Ting, Ching
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supporting information; scheme or table
p. 6503 - 6505
(2010/10/19)
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- New 3π-2spiro ladder-type phenylene materials: Synthesis, physicochemical properties and applications in OLEDs
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New routes to ladder-type phenylene materials 1 and 2 are described. The oligomers 1 and 2, which possess a "3π-2spiro" architecture, have been synthesized by using extended diketone derivatives 3 and 10 as key intermediates. The physicochemical properties of the new blue-light emitter 2 were studied in detail and compared with those of the less-extended 1. Owing to the recent development of fluorenone derivatives and their corresponding more conjugated analogues as potential electron-transport materials in organic light-emitting diodes (OLEDs) and as n-type materials for photovoltaic applications, we also report herein the thermal, optical and electrochemical behavior of the key intermediates, diketones 3 and 10. Finally, the application of dispiro 2 as a new light-emitting material in OLEDs is reported.
- Cocherel, Nicolas,Poriel, Cyril,Rault-Berthelot, Joelle,Barriere, Frederic,Audebrand, Nathalie,Slawin, Alexandra M. Z.,Vignau, Laurence
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supporting information; experimental part
p. 11328 - 11342
(2009/10/17)
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- PROCESS FOR THE SYNTHESIS OF HALOGENATED AROMATIC DIACIDS
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The production of high-purity halogenated aromatic diacids from halogenated dimethylbenzene by oxidation with an oxygen-containing gas is conducted using a four-component catalyst system and a two-stage temperature process.
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Page/Page column 15-16
(2008/12/07)
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- Cruciform p-n diblock conjugated oligomers for electroluminescent applications
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The optoelectronic properties of the cruciform p-n diblock oligomers 1-3 can be independently tuned by the oligofluorene and oxadiazole branches to increase the charge mobility. the Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2006.
- Wang, Hong-Yu,Feng, Jia-Chun,Wen, Gui-An,Jiang, Hong-Ji,Wan, Jun-Hua,Zhu, Rui,Wang, Chuan-Ming,Wei, Wei,Huang, Wei
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p. 667 - 670
(2007/10/03)
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- Novel alternating fluorene-based conjugated polymers containing oxadiazole pendants with various terminal groups
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A series of soluble alternating fluorene-based copolymers containing symmetrical and asymmetrical 1,3,4-oxadiazole (OXD) pendants with various terminal groups are synthesized by the palladium-catalyzed Suzuki coupling reaction. These polymers possess higher glass transition temperatures than that of the analogous dialkoxy-substituted polymer (PFPOC6) consisting of the same backbone without OXD pendants. The photophysical and electrochemical properties of these polymers are affected by the polar effect (electron-withdrawing group, -CN, and electron-donating group, -R or -OR) and the size effect (the size of the grafted side chain) of the OXD pendants. Owing to the large steric hindrance of OXD pendants, the aggregation of these polymers in solids is reduced, which results in almost identical PL emissions in both solution and solid states. The bulky OXD pendants on the polymer side chains can provide the polymer films with lower HOMO and LUMO energy levels and better electron injection property. Since only one emission peak is observed in both PL and EL spectra of these polymers, it is evidenced that effective energy transfer from the OXD pendants to the conjugated polymer backbones has occurred, thus eliminating the light emission from the OXD pendants. These asymmetrical OXD-substituted polymers have higher quantum yields and less aggregation in the solid state than the symmetrical OXD-substituted polymers. The symmetrical OXD-substituted polymer (P1) has a longer PL emission wavelength than the asymmetrical OXD-substituted polymers (P2-P8), which may be due to the improvement of the coplanarity between the polymer backbone and the symmetrical OXD pendants and/or the introduction of two electron-withdrawing OXD pendants.
- Sung, Hsiao-Hsien,Lin, Hong-Cheu
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p. 7945 - 7954
(2007/10/03)
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- Synthesis and preliminary testing of molecular wires and devices
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Presented here are several convergent synthetic routes to conjugated oligo(phenylene ethynylene)s. Some of these oligomers are free of functional groups, while others possess donor groups, acceptor groups, porphyrin interiors, and other heterocyclic interiors for various potential transmission and digital device applications. The syntheses of oligo(phenylene ethynylene)s with a variety of end groups for attachment to numerous metal probes and surfaces are presented. Some of the functionalized molecular systems showed linear, wire-like, current versus voltage (I(V)) responses, while others exhibited nonlinear I(V) curves for negative differential resistance (NDR) and molecular random access memory effects. Finally, the syntheses of functionalized oligomers are described that can form self-assembled monolayers on metallic electrodes that reduce the Schottky barriers. Information from the Schottky barrier studies can provide useful insight into molecular alligator clip optimizations for molecuar electronics.
- Tour, James M.,Rawlett, Adam M.,Kozaki, Masatoshi,Yao, Yuxing,Jagessar, Raymond C.,Dirk, Shawn M.,Price, David W.,Reed, Mark A.,Zhou, Chong-Wu,Chen, Jia,Wang, Wenyong,Campbell, Ian
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p. 5118 - 5134
(2007/10/03)
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- Imine-bridged planar poly(p-phenylene) derivatives for maximization of extended π-conjugation. The common intermediate approach
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Described are two approaches to planar conjugated poly(p-phenylene) (PPP) derivatives. The first approach, involving lactam bridges, was unsuccessful due to the insolubility of the 6(5H)-phenanthridinonyl moieties. The second approach, which utilized imine bridges, worked excellently since the compounds were generally soluble and the bridge formations were highly efficient. The main PPP backbone was synthesized via Pd(0)-catalyzed coupling of an arylbis(boronic ester) with an aryl dibromide. Imine bridges, which are formed by exposure of the polymer to trifluoroacetic acid or HCl, force the consecutive units into planarity. The bridging units are sp2 hybridized, thus allowing for greater π-electron flow between the consecutive phenyl units. The polymers, upon planarization, exhibit enormous bathochromic shifts of 210-240 nm. The optical spectra of the planar systems are compared to that of the parent nonplanarized polymers, oligo(p-phenylenes), and PPP. When the bridges were n-dodecyl- or n-octylphenyl-substituted, the fully planar structures could be made into flexible free-standing films. Additionally, an improved method is described in which a common intermediate, an aryl dibromo diacyl halide, could be used to prepare both the A and B units for the AB-type step growth polymerization. In one case, a selective alkylation or arylation of the acyl portions was accomplished using lower order cyanocuprates or Pd(0)-catalyzed ketone formation. For the second monomer, a bis-Curtius rearrangement, in the presence of tert-butyl alcohol, converted both carbonyl moieties to BOC protected amines.
- Lamba, Jaydeep J. S.,Tour, James M.
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p. 11723 - 11736
(2007/10/02)
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