Synthesis and electrochromic properties of triphenylamine containing copolymers: Effect of π‐bridge on electrochemical properties

In this study, a series of benzotriazole (BTz) and triphenylamine (TPA)‐based random copolymers; poly4‐(5‐(2‐dodecyl‐7‐methyl‐2H‐benzo[d][1,2,3]triazol‐4‐yl)thiophen‐2‐yl)‐N‐(4‐(5‐methylthiophen‐2‐yl)phenyl)‐N‐phenylaniline ( P1 ), poly4′‐(2‐dodecyl‐7‐methyl‐2H‐benzo[d][1,2,3]triazol‐4‐yl)‐N‐(4′‐methyl‐[1,1′‐biphenyl]‐4‐yl)‐N‐phenyl‐[1,1′‐biphenyl]‐4‐amine ( P2 ), and poly4‐(5′‐(2‐dodecyl‐7‐(5‐methylthiophen‐2‐yl)?2H‐benzo[d][1,2,3]triazol‐4‐yl)‐[2,2′‐bithiophen]‐5‐yl)‐N‐(4‐(5‐methylthiophen‐2‐yl)phenyl)‐N‐phenylaniline ( P3 ) were synthesized to investigate the effect of TPA unit and π‐bridges on electrochemical and spectroelectrochemical properties of corresponding polymers. The synthesis was carried out via Stille coupling for P1 , P3 , and Suzuki coupling for P2 . Electrochemical and spectral results showed that P1 has an ambipolar character, in other words it is both p‐type and n‐type dopable, whereas P2 and P3 have only p‐doping property. Effect of different π‐bridges and TPA unit on the HOMO and LUMO energy levels, switching time, and optical contrast were discussed. All polymers are promising materials for electrochromic devices. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 537–544     

Incorporation of different conjugated linkers into low band gap polymers based on 5,6‐Bis(octyloxy)‐2,1,3 benzooxadiazole for tuning optoelectronic properties

Four new 2,1,3‐benzooxadiazole‐based donor–acceptor conjugated polymers, namely poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSC), poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFC), poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSFL), and poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFFL), were synthesized via Stille polycondensation reaction. All polymers were found to be soluble in common organic solvents such as chloroform, tetrahydrofuran, and chlorobenzene. Their structures were verified by ¹H‐NMR and the molecular weights were determined by gel permeation chromatography (GPC). The polymer films exhibited broad absorption bands. Among all polymers, photovoltaic cells based on the device structure of ITO/PEDOT:PSS/PSBSC:PC₇₁BM(1:3, w/w)/LiF/Al revealed an open‐circuit voltage of 0.62 V, a short circuit current of 7.63 mA cm^?2 and a power conversion efficiency of 1.89%. This work demonstrates a good example for tuning absorption range, energy level, and photovoltaic properties of the polymers with different spacers and donor units can offer a simple and effective method to improve the efficiency of PSCs. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2459–2467     

Fused structures in the polymer backbone to investigate the photovoltaic and electrochromic properties of donor–acceptor‐type conjugated polymers

In this study, two new benzotriazole (BTz) and dithienothiophene (DTT) containing conjugated polymers were synthesized. After successful characterizations of the monomers by proton‐nuclear magnetic resonance (¹H NMR) and carbon‐NMR (¹³C NMR) techniques, poly(4‐(dithieno[3, 2‐b:2′,3′‐d]thiophen‐2‐yl)‐2‐(2‐octyldodecyl)‐2H‐benzo[d][1,2,3] triazole) P1 and poly(4‐(5‐(dithieno[3,2‐b:2′,3′‐d]thiophen‐2‐yl)thiophen‐2‐yl)‐2‐(2‐octyldodecyl)‐7‐(thiophen‐2‐yl)‐2H‐benzo[d][1,2,3]triazole) P2 were synthesized via a typical Stille coupling. Electrochemical and spectroelectrochemical studies showed that both polymers can be multipurpose materials and used in electrochromic and photovoltaic applications. Reported study indicated that incorporation of DTT into the structure leads to fast switching times compared with BTz‐based polymers and competent percentage transmittance in the near‐infrared region. Multichromism is important in the context of low‐cost flexible display device technology and both polymers are ambipolar and processable as well as multichromic. Throughout the preliminary photovoltaic studies, the best performances of photovoltaic devices were found as V_oc = 0.49 V, J_sc = 0.83 mA/cm², fill factor (FF) = 34.4%, and power conversion efficiency (PCE) = 0.14% for P1 , and as V_oc = 0.35 V, J_sc = 1.57 mA/cm², FF = 38.2%, and PCE = 0.21% for P2 . © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Multichromic benzimidazole‐containing polymers: Comparison of donor and acceptor unit effects

This study reports a comparative study on electrochromic properties of two donor–acceptor–donor (DAD)‐type polymers namely poly(2‐heptyl‐4,7‐di(thiophen‐2‐yl)‐1H‐benzo [d]imidazole) (BImTh) and poly(4,7‐bis(2,3‐dihydrothieno[3,4‐b] [1,4]dioxin‐5‐yl)‐2‐heptyl‐1H‐benzo[d]imidazole) (BImEd). DAD‐type monomers were polymerized electrochemically on indium tin oxide‐coated glass slides to determine the optical properties of the polymers. Electrochemical p‐doping experiments were performed to determine the band gap and absorption band values of the polymer films at different redox states. Polymerization of BImTh and BImEd yields multichromic polymers. Donor and acceptor effects are studied by comparing the PBImEd and PBImTh with corresponding benzotriazole derivatives. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis of novel isoindolone‐based medium‐sized macromolecules and triazole containing heterocyclic compounds

A series of novel isoindolone‐based macromolecules of medium‐sized heterocyclic rings, such as 7,8‐dihydro‐6H‐benzo[4,5][1,6,3]dioxazonino[2,3‐a]isoindol‐14(9aH)‐one derivatives ( 5a‐l ), were synthesized and its frame work incorporating with a triazole moiety on phenol, ie, 2‐(4‐((1‐(2‐methoxyphenyl)‐1H‐1,2,3‐triazol‐4‐yl)methoxy)phenyl)isoindoline‐1,3‐dione ( 9a‐f ) and also a triazole moiety on carboxylic acid, ie, (1‐(2‐methoxyphenyl)‐1H‐1,2,3‐triazol‐4‐yl)methyl 4‐(1,3‐dioxoisoindolin‐2‐yl)benzoate derivatives ( 13a‐e ) with various substitutions on aryl ring system have synthesized. All the synthesized compounds were characterized and confirmed with IR, ¹H NMR_, ¹³C NMR, and ESI mass spectral analysis.     

Heteroarene‐fused π‐conjugated main‐chain polymers containing 4,7‐bis(4‐octylthiophen‐2‐yl)benzo[c][1,2,5]thiadiazole or 2,5‐bis(4‐octylthiophen‐2‐yl)thiazolo[5,4‐d]thiazole and their application to photovoltaic devices

Two conjugated main‐chain polymers consisting of heteroarene‐fused π‐conjuagted donor moiety alternating with 4,7‐bis(5‐bromo‐4‐octylthiophen‐2‐yl)benzo[c][1,2,5]thiadiazole (P1) or 2,5‐bis(5‐bromo‐4‐octylthiophen‐2‐yl) thiazolo[5,4‐d]thiazole (P2) units have been synthesized. They are intrinsically amorphous in nature and do not exhibit crystalline melting temperatures during thermal analysis. The effect of the fused rings on the thermal, optical, electrochemical, charge transport, and photovoltaic properties of these polymers has been investigated. The polymer (P1) containing 4,7‐bis(5‐bromo‐4‐octylthiophen‐2‐yl)benzo[c][1,2,5] thiadiazole has a broad absorption extending from 300 to 600 nm with optical bandgaps as low as 2.02 eV. The HOMO levels (5.42 to 5.29 eV) are more sensitive to the choice of acceptor. The polymers were employed to fabricate organic photovoltaic cells with methanofullerene [6,6]‐phenyl C71‐butyric acid methyl ester (PC₇₁BM). As a result, the polymer solar cell device containing P1 had the best preliminary results with an open‐circuit voltage of 0.61 V, a short‐circuit current density of 6.19 mA/cm², and a fill factor of 0.32, offering an overall power conversion efficiency of 1.21%. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Triarylamine N‐functionalized 3,6‐linked carbazole main chain polymers and copolymers: Preparation and physical properties

The preparation of triarylamine N‐functionalized 3,6‐linked carbazole homopolymers as well as alternating copolymers with 2,5‐diphenyl‐[1,3,4]oxadiazole and benzo[1,2,5]thiadiazole was undertaken using Suzuki cross‐coupling polymerization procedures associating 3,6‐bis(4,4,5,5‐tetramethyl‐[1,3,2]dioxaborolan‐2‐yl)‐9‐(bis[4‐(2‐butyl‐octyloxy)‐phenyl]‐amino‐phen‐4‐yl)‐carbazole and, respectively, 3,6‐dibromo‐9‐(bis[4‐(2‐butyl‐octyloxy)‐phenyl]‐amino‐phen‐4‐yl)‐carbazole, 2,5‐bis(4‐bromo‐phenyl)‐[1, 3,4]oxadiazole, and 4,7‐dibromo‐benzo[1,2,5]thiadiazole. Both the carbazole homopolymer and alternating copolymer with 2,5‐diphenyl‐[1,3,4]oxadiazole were found as wideband gap materials emitting in the blue part of the electromagnetic spectrum while the carbazole alternating copolymer with 4,7‐benzo[1,2,5]thiadiazole had a narrower band gap and emitted in the orange part of the electromagnetic spectrum. The new polymers are thermally stable up to 300 °C. A discussion of the electrochemical and optical properties of the new polymers is presented. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5957–5967, 2007.     

Effective and Functional Surface Design for Biosensing Applications Based on a Novel Conducting Polymer and PMMA/Clay Nanocomposite

Surface functionalization plays a crucial role in the design of biosensors. For this purpose, a novel functional monomer, 6‐(4,7‐bis(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)‐2H‐benzo[d][1,2,3]triazol‐2‐yl)hexan‐1‐amine (BEDOA‐6), was designed and synthesized. Poly(BEDOA‐6) was utilized as an immobilization matrix for glucose oxidase biosensor construction. Moreover, polymethylmethacrylate (PMMA) layered silicate nanocomposites were prepared by in situ suspension polymerization. Conducting polymer surface was modified with PMMA/clay nanocomposite material and a glucose biosensor was developed. In addition, XPS and SEM were utilized to characterize the surface properties. The biosensor shows a wide linear range between 2.8 µM and 1.2 mM to glucose with a low detection limit of 1.99 µM. Finally, the biosensor was tested on serum samples containing actual human blood. The results were in well‐agreement with a reference method.     

Green One‐Pot Solvent‐Free Synthesis of Pyrazolo[1,5‐a]pyrimidines,Azolo[3,4‐d]pyridiazines,and Thieno[2,3‐b]pyridines Containing Triazole Moiety

Synthesis of pyrazolo[1,5‐a]pyrimidines, [1,2,4]triazolo[1,5‐a]pyrimidine, 8,10‐dimethyl‐2‐(5‐methyl‐1‐phenyl‐4,5‐dihydro‐1H‐1,2,3‐triazol‐4‐yl)pyrido[2′,3′:3,4]‐pyrazolo[1,5‐a]pyrimidine, benzo[4,5]imidazo[1,2‐a]pyrimidine via heterocyclic amines, and sodium 3‐hydroxy‐1‐(5‐methyl‐1‐phenyl‐1H‐1,2,3‐triazole‐4‐yl)prop‐2‐en‐1‐one were carried out. Also, synthesis of isoxazoles, and pyrazoles from sodium 3‐hydroxy‐1‐(5‐methyl‐1‐phenyl‐1H‐1,2,3‐triazole‐4‐yl)prop‐2‐en‐1‐one and hydroxymoyl chlorides and hydrazonoyl halides, respectively, were made. Analogously, (1,2,3‐triazol‐4‐yl)thieno[2,3‐b]pyridine derivatives were obtained from sodium 3‐hydroxy‐1‐(5‐methyl‐1‐phenyl‐1H‐1,2,3‐ triazole‐4‐yl)prop‐2‐en‐1‐one and cyanothioacetamide followed by its reacting with active methylene compounds. In addition to full characterization of all synthesized compounds, they were tested to evaluate their antimicrobial activities, and some compounds showed competitive activities to those of tetracycline, the typical antibacterial drug, and clotrimazole, the typical antifungal drug.     

Spray‐processable thiazolothiazole‐based copolymers with altered donor groups and their electrochromic properties

Two novel thiazolo[5,4‐d]thiazole containing donor–acceptor type alternating copolymers, poly[2‐(5‐(2‐decyl‐2H‐benzo[d][1,2,3]triazol‐4‐yl)thiophen‐2‐yl)‐5‐(thiophen‐2‐yl)thiazolo[5,4‐d]thiazole] (BTzTh) and poly[2‐(5‐(2‐decyl‐2H‐benzo[d][1,2,3]triazol‐4‐yl)furan‐2‐yl)‐5‐(furan‐2‐yl)thiazolo[5,4‐d]thiazole] (BTzFr) were synthesized by Stille coupling polymerization and their electrochemical and electrochromic properties were explored. Electrochemical activities of the spray‐casted polymer films were determined by cyclic voltammetry. To evaluate the effect of thiophene and furan moieties on the optical properties of the copolymers, spectroelectrochemistry studies were performed. To examine the switching abilities, copolymer films were subjected to a double potential step chronoamperometry in their local maximum absorptions. Both thiazolothiazole‐containing copolymers showed multichromic properties with low band‐gap values 1.7 and 1.9 eV for BTzTh and BTzFr, respectively. The decent electrochromical properties together with solution processability make them important candidates for electrochromic applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3901–3906     

Effects of substituted side‐chain position on donor–acceptor conjugated copolymers

The optical properties and electrical properties of a series of low‐band‐gap conjugated copolymers, in which alkyl side chains were substituted at various positions, were investigated using donor–acceptor conjugated copolymers consisting of a cyclopentadithiophene derivative and dithienyl‐benzothiadiazole. With substituted side chains, the intrinsic properties of the copolymers were significantly altered by perturbations of the intramolecular charge transfer. The absorption of poly[2, 6‐(4,4‐bis(2‐octyl)‐4H‐cyclopenta‐[2,1‐b:3,4‐b′]dithiophene)‐alt‐4, 7‐bis(4‐octyl‐thiophene‐2‐yl)benzo‐2,1,3‐thiadiazole] [ PCPDT‐ttOTBTOT ( P2 )], which assumed a tail–tail configuration, tended to blue shift relative to the absorption of poly[2,6‐(4,4‐bis(2‐octyl)‐4H‐cyclopenta‐[2,1‐b:3,4‐b′]dithiophene)‐alt‐4,7‐bis (thiophene‐2‐yl)benzo‐2,1,3‐thiadiazole] [ PCPDT‐TBTT ( P1 )]. The absorption of poly[2,6‐(4,4‐bis(2‐octyl)‐4H‐cyclopenta‐[2,1‐b:3, 4‐b′]dithiophene)‐alt‐4,7‐bis(3‐octyl‐thiophene‐2‐yl)benzo‐2,1,3‐thiadiazole] [ PCPDT‐hhOTBTOT ( P3 )], which assumed a head–head configuration, was blue shifted relative to that of P2 . The electrical transport properties of field‐effect transistors were sensitive to the side chain position. The field‐effect mobility in P2 (μ₂ = 1.8 × 10^?3 cm²/V s) was slightly lower than that in P1 (μ₁ = 4.9 × 10^?3 cm²/V s). However, the mobility of P3 was very low (μ₃ = 3.8 × 10^?6 cm²/V s). Photoexcitation spectroscopy showed that the charge generation efficiency (shown in transient absorption spectra) and polaron pair mobility in P1 and P2 were higher than in P3 , yielding P1 and P2 device performances that were better than the performance of devices based on P3 . © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis and characterization of isoindigo‐based polymers using CH‐arylation polycondensation reactions for organic photovoltaics

A series of three new low bandgap donor–acceptor–donor–acceptor^/ (D–A–D–A^/) polymers have been successfully synthesized based on the combination of isoindigo as the electron‐deficient acceptor and 3,4‐ethylenedioxythiophene as the electron‐rich donor, followed by CH‐arylation with different acceptors (4,7‐dibromo[c][1,2,5]‐(oxa, thia, and/or selena)diazole ( 4a‐c )). These polymers were used as donor materials for photovoltaic applications. All of the polymers are highly stable and show good solubility in chlorinated solvents. The highest power conversion efficiency of 1.6% was achieved in the bulk heterojunction photovoltaic device that consisted of poly ((E)?6‐(7‐(benzo‐[c][1,2,5]‐thiadiazol‐4‐yl)?2,3‐dihydrothieno‐[3,4‐b][1,4]dioxin‐5‐yl)?6′‐(2,3‐dihydrothieno‐[3,4‐b][1,4]‐dioxin‐5‐yl)?1,1′‐bis‐(2‐octyldodecyl)‐[3,3′‐biindolinylidene]‐2,2′‐dione) as the donor and PC₆₁BM as the acceptor, with a short‐circuit current density (J_sc) of 8.10 mA/cm², an open circuit voltage (V_oc) of 0.56 V and a fill factor of 35%, which indicates that these polymers are promising donors for polymer solar cell applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2926–2933     

Dibenzophenazine derivatives as visible photosensitizers for diaryliodonium salts

The use of two dibenzo[a,c]phenazine derivatives, 10,13‐bis(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)dibenzo[a,c]phenazine and 10,13‐bis(4‐hexylthiophen‐2‐yl)dibenzo[a,c]phenazine are reported as photosensitizers for diaryliodonium salt photoinitiators. Novel dyes based on the dibenzo[a,c]phenazine skeleton are shown to be efficient in carrying out the cationic photopolymerizations. Representative examples of different types of monomers including epoxide, and vinyl monomers are polymerized in the presence of the photosensitizers and diphenyliodonium hexafluorophosphate (Ph₂I⁺PF). Polymerizations are initiated at room temperature using long wavelength UV and visible light, and monitored by optical pyrometry. The photopolymerization of an epoxide monomer via solar irradiation is also demonstrated. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Naphthodioxinone‐1,3‐benzodioxole as photochemically masked one‐component type II photoinitiator for free radical polymerization

A 1,3‐benzodioxole derivative of naphthodioxinone, namely 2‐(benzo[d][1,3]dioxol‐5‐yl)‐9‐hydroxy‐2‐phenyl‐4H‐naphtho[2,3‐d][1,3]dioxin‐4‐one was synthesized and characterized. Its capability to act as caged one‐component Type II photoinitiator for free radical polymerization was examined. Upon irradiation, this photoinitiator releases 5‐benzoyl‐1,3‐benzodioxole possessing both benzophenone and 1,3‐dioxole groups in the structure as light absorbing and hydrogen donating sites, respectively. Subsequent photoexcitation of the benzophenone chromophore followed by hydrogen abstraction generates radicals capable of initiating free radical polymerization of appropriate monomers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Dithienobenzimidazole‐containing conjugated donor–acceptor polymers: Synthesis and characterization

The synthesis of two new conjugated polymers based on the relatively under‐exploited monomer, 5,8‐dibromo‐2‐[5‐(2‐hexyldecyl)‐2‐thienyl]‐1H‐dithieno[3,2‐e:2′,3′‐g]benzimidazole (dithienobenzimidazole, DTBI ), and either 4,7‐bis[4‐hexyl‐5‐(trimethylstannyl)‐2‐thienyl]‐2,1,3‐benzothiadiazole ( BTD ) or 2,6‐bis(trimethylstannyl)‐4,8‐bis(5‐(2‐ethylhexyl) thiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithiophene ( BDT ) is described. The polymers were synthesized via Stille polycondensation and characterized by traditional methods (¹H NMR, gel‐permeation chromatography, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, thermal gravimetric analysis, differential scanning calorimetry, ultraviolet–visible spectroscopy, photoluminescence, and cyclic voltammetry). Prior to their synthesis, trimer structures were modeled by DFT calculations facilitating a further understanding of the systems' electronic and geometric structure. Polymers were titrated with acid and base to take advantage of their amphiprotic imidazole moiety and their optical response monitored with ultraviolet–visible spectroscopy. Finally, pristine polymer thin‐films were treated with acid and base to evaluate (de)protonation's effect on system electronics, but thin‐film degradation was encountered. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 60–69     

Synthesis and characterization of cyclopentadithiophene‐based low bandgap copolymers containing electron‐deficient benzoselenadiazole derivatives for photovoltaic devices

We have synthesized two cyclopentadithiophene (CDT)‐based low bandgap copolymers, poly[(4,4‐bis(2‐ethyl‐hexyl)‐4H‐cyclopenta[2,1‐b:3,4‐b′]dithiophene‐2,6‐diyl)‐alt‐(benzo[c][1,2,5]selenadiazole‐4,7‐diyl)] (PCBSe) and poly[(4,4‐bis(2‐ethyl‐hexyl)‐4H‐cyclopenta[2,1‐b:3,4‐b′]dithiophene‐2,6‐diyl)‐alt‐(4,7‐dithiophen‐2‐yl‐benzo[c][1,2,5]selenadiazole‐5,5′‐diyl)] (PCT2BSe), for use in photovoltaic applications. Through the internal charge transfer interaction between the electron‐donating CDT unit and the electron‐accepting benzoselenadiazole, we realized exceedingly low bandgap polymers with bandgaps of 1.37–1.46 eV. The UV–vis absorption maxima of PCT2BSe were subjected to larger hypsochromic shifts than those of PCBSe, because of the distorted electron donor–acceptor (D–A) structures of the PCT2BSe backbone. These results were supported by the calculations of the D–A complex using the ab initio Hartree‐Fock method with a split‐valence 6‐31G* basis set. However, PCT2BSe exhibited a better molar absorption coefficient in the visible region, which can lead to more efficient absorption of sunlight. As a result, PCT2BSe blended with [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PC₆₁BM) exhibited a better photovoltaic performance than PCBSe because of the larger spectral overlap integral with respect to the solar spectrum. Furthermore, when the polymers were blended with PC₇₁BM, PCT2BSe showed the best performance, with an open circuit voltage of 0.55 V, a short‐circuit current of 6.63 mA/cm², and a power conversion efficiency of 1.34% under air mass 1.5 global illumination conditions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1423–1432, 2010     

Donor–acceptor‐structured naphtodithiophene‐based copolymers for organic thin‐film transistors

New donor–acceptor (D‐A) polymers, poly(4,5‐bis(2‐octyldodecyloxy)naphto[2,1‐b:3,4‐b']dithiophenebenzo[c][1,2,5]thiadiazole) (PNDT‐B) and poly(4,5‐bis(2‐octyldodecyloxy)naphto [2,1‐b:3,4‐b′]dithiophene‐4,7‐di(thiophen‐2‐yl)benzo[c][1,2,5]thiadiazole) (PNDT‐TBT), with the extended π‐electron delocalization of naphtho[2,1‐b:3,4‐b']dithiophene, were successfully synthesized by Suzuki and Stille coupling reactions. The structure and physical properties of polymers were characterized by DFT calculation, UV–vis absorption, cyclovoltammetry, TGA and DSC analyses. X‐ray diffraction studies indicated a relatively highly ordered intermolecular structure in PNDT‐TBT after annealing. This high degree of molecular order resulted from the crystallinity and increasing planarity, provided by the thiophene linker groups and the interdigitation of the long alkoxy side chains. The new D‐A polymer, PNDT‐TBT, exhibited a p‐type carrier mobility of 0.028 cm²/Vs and an on/off ratio of 5.9 × 10³. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 525–531     

Theoretical Investigation on the Electron and Energy Transfer between Peripheral Carrier Transport Groups and Central Chromophores in Electroluminescent Materials

The molecular materials with structures of luminescent core and peripheral carrier groups (e.g. carbazoles), have exhibited high‐performance in organic light‐emitting diodes (OLEDs). Present work is to understand the basic process of electronic and energy exchange between the peripheral functional groups and the central core through quantum chemical analysis. As an example, 4,7‐bis(9,9‐bis(6‐(9H‐carbazol‐9‐yl)hexyl)‐9H‐fluoren‐2‐yl)benzo[c]‐[1,2,5]thiadiazole (TCBzC) is investigated in regards to optoelectronic properties using density functional theory (DFT). The results suggest that the forbidden transition from peripheral carbazole to the central chromophore core makes for separated electrical and optical properties, and high performance electroluminescence (EL) is mainly attributed to the energy‐transfer from carbazoles to the fluorene derivative core     

Diketopyrrolopyrrole‐based liquid crystalline conjugated donor–acceptor copolymers with reduced band gap for polymer solar cells

A new liquid crystalline (LC) acceptor monomer 2,5‐bis[4‐(4′‐cyanobiphenyloxy)dodecyl]‐3,6‐dithiophen‐2‐yl‐pyrrolo[3,4‐c]pyrrole‐1,4‐dione (TDPPcbp) was synthesized by incorporating cyanobiphenyl mesogens into diketopyrrolopyrrole (DPP). The monomer was copolymerized with bis(2‐ethylhexyloxy)benzo[1,2‐b:4,5‐b′] dithiophene (BDT) and N‐9′‐heptadecanylcarbazole (CB) donors to obtain donor–acceptor alternating copolymers poly[4,8‐bis(2‐ethylhexyloxy)benzo[1,2‐b:4,5‐b′]dithiophene‐alt‐3,6‐bis(thiophen‐5‐yl)‐2,5‐bis[4‐(4′‐cyanobiphenyloxy)dodecyl]‐2,5‐dihydropyrrolo[3,4‐c]pyrrole‐1,4‐dione] (PBDTDPPcbp) and poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐3,6‐bis(thiophen‐5‐yl)‐2,5‐bis[4‐(4′‐cyano‐biphenyloxy)dodecyl]‐2,5‐dihydropyrrolo[3, 4‐c]pyrrole‐1,4‐dione] (PCBTDPPcpb) with reduced band gap, respectively. The LC properties of the copolymers, the effects of main chain variation on molecular packing, optical properties, and energy levels were analyzed. Incorporating the mesogen cyanobiphenyl units not only help polymer donors to pack well through mesogen self‐organization but also push the fullerene acceptor to form optimized phase separation. The bulk heterojunction photovoltaicdevicesshow enhanced performance of 1.3% for PBDTDPPcbp and 1.2% for PCBTDPPcbp after thermal annealing. The results indicate that mesogen‐controlled self‐organization is an efficient approach to develop well‐defined morphology and to improve the device performance. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Synthesis of Amino,Azido, Nitro,and Nitrogen‐Rich Azole‐Substituted Derivatives of 1H‐Benzotriazole for High‐Energy Materials Applications

The amino, azido, nitro, and nitrogen‐rich azole substituted derivatives of 1H‐benzotriazole have been synthesized for energetic material applications. The synthesized compounds were fully characterized by ¹H and ¹³C NMR spectroscopy, IR, MS, and elemental analysis. 5‐Chloro‐4‐nitro‐1H‐benzo[1,2,3]triazole ( 2 ) and 5‐azido‐4,6‐dinitro‐1H‐benzo[1,2,3]triazole ( 7 ) crystallize in the Pca2₁ (orthorhombic) and P2₁/c (monoclinic) space group, respectively, as determined by single‐crystal X‐ray diffraction. Their densities are 1.71 and 1.77 g cm^?3, respectively. The calculated densities of the other compounds range between 1.61 and 1.98 g cm^?3. The detonation velocity (D) values calculated for these synthesized compounds range from 5.45 to 8.06 km s^?1, and the detonation pressure (P) ranges from 12.35 to 28 GPa.