Electronic Properties and Photovoltaic Performances of a Series of Oligothiophene Copolymers Incorporating Both Thieno[3,2‐b]thiophene and 2,1,3‐Benzothiadiazole Moieties

A series of donor‐acceptor alternated conjugated copolymers, composed of thiophene, bithiophene, thieno[3,2‐b]thiophene, and 2,1,3‐benzothiadiazole units and differing from each other by the nature and the number of 3‐alkylthiophene in the backbone, have been synthesized by Stille cross‐coupling polymerization. The material's optical and electrochemical properties, in solution and in thin films, have been investigated using UV‐Visible absorption and cyclic voltammetry. Bulk heterojunction solar cells using blends of the newly synthesized copolymers, as electron donor, and C60‐PCBM or C70‐PCBM, as electron transporting material, have been elaborated. A maximum power conversion efficiency of 1.8% is achieved with a 1:4 PPBzT²‐C12:C70‐PCBM weight ratio.

     

以噻吩[3,4-b]并噻吩为核的近红外电子受体及其高性能光探测器

为了实现在近红外区的良好光电响应,设计合成了一种A-D-A型有机电子受体TCIC.由于采用具有强醌式效应的噻吩[3,4-b]并噻吩单元为核,TCIC在780～1000 nm的近红外区具有强吸收以及合适的能级结构,可与常用的聚合物给体PCE10的吸收和能级相匹配.于是,采用2种器件结构,制备了基于PCE10×TCIC共混...     

受体强度及D/A比对D-A型共轭聚合物几何结构和电子性质的影响研究

以Thieno[3,2-b]thiophene(TT)为电子供体(D),Benzo[c][1,2,5]thiadiazole(BT)、[1,2,5]thiadiazolo[3,4-g]quinoxaline(Td Q)、和Benzobis[1,2,5]thiadiazole(BBT)为电子受体(A),设计了供体-受体摩尔比(D/A比)分别为1∶1和2∶1的6种供体-受体交替排列的D-A型共轭聚合物.采用杂化的密度泛函方法(B3LYP),在6-31G(d)理论水平下研究了其几何结构和电子性质.研究发现,电子受体接受电子的能力和D/A比对基于TT的D-A型共轭聚合物的几何结构和电子性质有重要影响.对于D/A比相同的聚合物,电子受体接受电子的能力增强,聚合链上桥键的键长缩短,供体环上的碳碳双键的平均键长(L_(AD))增大而碳碳单键平均键长(L_(AS))减小.对由相同电子供体和受体构成的聚合物,D/A比增加,桥键变长.电子受体对D/A比为2∶1的聚合物的性质影响有显明的规律.当电子受体接受电子的能力增强,聚合物的能隙(Eg)变窄、价带(W_(VB))和导带(W_(CB))变宽、载流子有效质量(m_H和m_L)减小.研究发现,p-TdQ-TT和p-BBT-DTT能隙窄,能带相对较宽、载流子有效质量小,可能是的潜在的本征导电聚合物材料.     

Novel ferroelectric liquid crystals based on fused thieno[3,2-b]furan and thieno[3,2-b]thiophene cores

Several series of new benzofused thieno[3,2-b]furan- and thieno[3,2-b]thiophene-based derivatives have been synthesized and their mesomorphic properties investigated. All the studied compounds exhibit a SmC* phase with very wide temperature interval. Additionally, some types of the compounds show the cholesteric, SmA or blue phase. In the ferroelectric SmC* phase we evaluated physical properties of relevance for possible applications.     

新型含供体-受体单元的聚对苯撑乙炔光伏材料的合成及性能研究

摘要：通过钯催化的Heck偶联缩聚反应,合成出了两种新的主链含对苯二乙炔,2-吡喃-4-烯-丙二腈衍生物的共轭聚合物。目标聚合物在一般有机溶剂中具有很好的溶解性;聚合物和TiO2组成的体相异质结薄膜表现出强的光诱导效应;电化学和光化学研究表明聚合物的能隙在1.7-1.85ev。这些表明它们是一类很有潜力的光伏材料。     

Aromatic Heterocycle 1,3,4‐Oxadiazole‐Substituted Thieno[3,4‐b]thiophene to Build Low‐Bandgap Polymer for Photovoltaic Application

Electron‐deficient heterocycle 1,3,4‐oxadiazole is first introduced to the 2‐position of thieno[3,4‐b]thiophene (TT) to construct a new building block 2‐(thieno[3,4‐b]thiophen‐2‐yl)‐5‐(alkylthio)‐1,3,4‐oxadiazole (TTSO) with alkylthio chain. The polymer PBDT–TTSO based on TTSO and benzodithiophene (BDT) exhibits a deep lying highest occupied molecular orbital (HOMO) energy level of −5.32 eV and low‐bandgap of 1.62 eV. The power conversion efficiency (PCE) of 5.86% is obtained with a relatively high V _OC of 0.74 V, a J _SC of 13.1 mA cm⁻², and FF of 60.5%. Furthermore, as S atom in thioether can be oxidized easily, the optoelectronic properties of PBDT–TTSO treated with different oxidants are preliminary investigated. Interestingly, the oxidation products still maintain high PCE with reduction less than 30%. This work demonstrates a new method to regulate HOMO energy levels by introducing electron‐deficient aromatic heterocyclic moiety.

     

Synthesis and Characterization of a Thiophene Copolymer for Photovoltaic Application

A soluble thiophene copolymer having polar and non polar side groups was synthesized and its photovoltaics performance was investigated. The synthesized copolymer was characterized using Nuclear Magnetic Resonance (NMR) and optical spectroscopy. Dye sensitized solar cells were fabricated using this copolymer as sensitizer. An open-circuit voltage of 0.50V, a short-circuit current density of 1.195 mA/cm² and an overall power conversion efficiency of 0.3% were measured.     

Synthesis of Thieno[3,4-b]pyrazine-based Alternating Conjugated Polymers via Direct Arylation for Near-infrared OLED Applications

Three alternating conjugated polymers,namely PFTP,PCz TP,and PSi TP,which combine a thieno[3,4-b]pyrazine(TP)unit with different benzene-based donor units such as 9,9-dioctylfluorene,9-heptadecyl-9H-carbazole and 5,5-dioctyl-5H-dibenzo[b,d]silole,were synthesized in good yield(>85%)and high molecular weight up to Mn=5.82×10⁴ via direct arylation polymerization(DAr P).All the resultant polymers exhibit moderate bandgap of about 1.80 e V and strong deep red/near-infrared emitting in the solid state.Among them,the PSi TP-based electroluminescence(EL)devices with an architecture of ITO/PEDOT:PSS/PTAA/emitting layer/TPBi/Li F/Al give the best performance with a maximum luminance of 2543 cd/m² at 478 m A/cm².This work expands the application scope of high-performance conjugated polymers which can be synthesized by DAr P.     

Adsorption and thermal decomposition of 2-octylthieno[3,4-b]thiophene on Au(111)

The adsorption and thermal stability of 2-octylthieno[3,4-b]thiophene (OTTP) on the Au(111) surfaces have been studied using scanning tunneling microscopy (STM), temperature programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). UHV-STM studies revealed that the vapor-deposited OTTP on Au(111) generated disordered adlayers with monolayer thickness even at saturation coverage. XPS and TPD studies indicated that OTTP molecules on Au(111) are stable up to 450K and further heating of the sample resulted in thermal decomposition to produce H(2) and H(2)S via C-S bond scission in the thieno-thiophene rings. Dehydrogenation continues to occur above 600K and the molecules were ultimately transformed to carbon clusters at 900K. Highly resolved air-STM images showed that OTTP adlayers on Au(111) prepared from solution are composed of a well-ordered and low-coverage phase where the molecules lie flat on the surface, which can be assigned as a (9×2√33)R5° structure. Finally, based on analysis of STM, TPD, and XPS results, we propose a thermal decomposition mechanism of OTTP on Au(111) as a function of annealing temperature.     

Mono- and Di-Pyrene [60]Fullerene and [70]Fullerene Derivatives as Potential Components for Photovoltaic Devices

In the present work, we report the successful synthesis and characterization of six (two new) fullerene mono- and di-pyrene derivatives based on C₆₀ and C₇₀ fullerenes. The synthesized compounds were characterized by spectral methods (ESI-MS, ¹H-NMR, ¹³C-NMR, UV-Vis, FT-IR, photoluminescence and photocurrent spectroscopy). The energy of HOMO and LUMO levels and the band gaps were determined from cyclic voltammetry and compared with the theoretical values calculated according to the DFT/B3LYP/6-31G(d) and DFT/PBE/6-311G(d,p) approach for fully optimized molecular structures at the DFT/B3LYP/6-31G(d) level. Efficiency of solar cells made of PTB7: C₆₀ and C₇₀ fullerene pyrene derivatives were analyzed based on the determined energy levels of the HOMO and LUMO orbitals of the derivatives as well as the extensive spectral results of fullerene derivatives and their mixtures with PTB7. As a result, we found that the electronic and spectral properties, on which the efficiency of a photovoltaic cell is believed to depend, slightly changes with the number and type of pyrene substituents on the fullerene core. The efficiency of constructed solar cells largely depends on the homogeneity of the photovoltaic layer, which, in turn, is a derivative of the solubility of fullerene derivatives in the solvent used to apply these layers by spincoating.     

Synthesis and Application of 2-Arylazo-3-Cyano Thieno [2,3-b]Naphthoquinones

The paper describes the synthesis of 2-amino-3-cyanothieno[2,3-b]naphthoquinone and its utilisation to prepare range of azo disperse dyes. These novel arylazo dyes were studied with respect to their color and constitution relationship. Application of these dyes on polyester fibres and their fastness properties were stated. These dyes were characterised by PMR, IR and visible absorption spectra.     

New Polymer Syntheses Part 60: A Facile Synthetic Route to Polyamides Based on Thieno[2,3-b]thiophene and Their Corrosion Inhibition Behavior

Polyamides containing thieno[2,3-b]thiophene moiety were prepared via a simple polycondensation reaction of the diaminothieno[2,3-b]thiophene monomer 1 a with different kinds of diacid chlorides(including oxalyl, adipoyl, sebacoyl, isophthaloyl,terephthaloyl, 4,4′-azodibenzoyl, 3,3′-azodibenzoyl, p-phenylene diacryloyl) in the presence of Li Cl and NMP as a solvent through lowtemperature solution polycondensation. The chemical structures of model compound and synthesized polyamides were confirmed by FTIR, nuclear magnetic resonance spectroscopy(including ~1H-NMR and ~(13)C-NMR) and elemental analysis. In addition, the thermal stability, crystallinity structure and surface morphology of synthesized polyamides were characterized via thermogravametric analysis(TGA), wide-angle X-ray diffraction analysis(WAXD) and scanning electron microscopy(SEM). Also, the corrosion inhibition behavior of selected examples of polyamides was investigated; the inhibitive effect of the investigated polymers for carbon steel in 1.0 mol·L~(-1) HCl was studied using potentiodynamic polarization(PDP) and electrochemical impedance spectroscopy(EIS) methods. PDP results displayed that the polyamides containing thieno[2,3-b]thiophene moiety can be as mixed-type inhibitors. The inhibition efficiency(P, %) was found to be in the range from 67.13% to 96.01%. There is an increase in P by the synthesized polymers in comparison to the starting monomer.The adsorption of these polymers was found to obey Langmuir adsorption isotherm.     

Synthesis of a Novel Low‐Bandgap Polymer Based on a Ladder‐Type Heptacyclic Arene Consisting of Outer Thieno[3,2‐b]thiophene Units for Efficient Photovoltaic Application

A novel conjugated polymer PIDTT‐quinoxaline (Qx) based on the coplanar thieno[3,2‐b]thiophene‐phenylene‐thieno[3,2‐b]thiophene structure is synthesized and evaluated as an electron‐donor material for bulk‐heterojunction polymer solar cells (BHJ PSCs). The absorption spectra, electrochemical, charge transport, and film morphology properties as well as theoretical modeling of PIDTT‐Qx are investigated to understand its intrinsic structure–property relationship. As expected, this polymer with an extended π‐conjugated backbone exhibits a narrow‐bandgap and board absorption spectrum for enhanced light harvesting. BHJ PSCs (ITO/PEDOT:PSS/polymer:PC₇₁BM/interlayer/Al) afford a maximum power conversion efficiency of 5.05% with an open‐circuit voltage of 0.84 V, a short‐circuit current density of 11.26 mA cm⁻², and a fill factor of 53.4%. These results demonstrate the potential of PIDTT‐Qx as an efficient electron‐donor material for BHJ PSCs.

     

Novel [1,2,4]triazolo[3,4-b][1,3,4]thiadiazine and [1,2,4]triazolo[3,4-b][1,3,4]thiadiazepine Derivatives: Synthesis,Anti-Viral In Vitro Study and Target Validation Activity

This study of the interaction system of binucleophilic 3-substituted 4-amino-4H-1,2,4-triazole-5-thiols and 3-phenyl-2-propynal made it possible to develop a new approach to synthesis of such isomeric classes as 7-benzylidene-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine and 8-phenyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazepine. Among the 20 compounds studied in vitro against influenza A/Puerto Rico/8/34 (H1N1) virus, half of them demonstrated selectivity index (SI) of 10 or higher and one of them (4-((3-phenylprop-2-yn-1-yl)amino)-4H-1,2,4-triazole-3-thiol) possessed the highest (SI > 300). Docking results and values showed that the preferred interactant for our ligands was M2 proton channel of the influenza A virus. Protein-ligand interactions modeling showed that the aliphatic moiety of ligands could negatively regulate target activity level.     

Dithienocyclopentathieno[3,2‐b]thiophene Hexacyclic Arene for Solution‐Processed Organic Field‐Effect Transistors and Photovoltaic Applications

We have developed a ladder‐type dithienocyclopentathieno[3,2‐b]thiophene ( DTCTT ) hexacyclic unit in which the central thieno[3,2‐b]thiophene ring was covalently fastened to two adjacent thiophene rings through carbon bridges, thereby forming two connected cyclopentadithiophene ( CPDT ) units in a hexacyclic coplanar structure. This stannylated Sn‐DTCTT building block was copolymerized with three electron‐deficient acceptors, dibromo‐thieno[3,4‐c]pyrrole‐4,6‐dione ( TPD ), dibromo‐benzothiadiazole ( BT ), and dibromo‐phenanthrenequinoxaline ( PQX ), by Stille polymerization, thereby furnishing a new class of alternating donor–acceptor copolymers: PDTCTTTPD , PDTCTTBT , and PDTCTTPQX , respectively. Field‐effect transistors based on PDTCTTPQX and PDTCTTBT yielded high hole mobilities of 0.017 and 0.053 cm² V^?1 s^?1, respectively, which are among the highest performances among amorphous donor–acceptor copolymers. A bulk heterojunction solar cell that incorporated PDTCTTTPD with the lower‐lying HOMO energy level delivered a higher V_oc value of 0.72 V and a power conversion efficiency (PCE) value of 2.59 %.     

辛氧基苯基取代的吡啶并[3,4-b]吡嗪染料的合成与光伏性能研究

为了进一步提高电池的开路电压, 把吡啶并吡嗪核上的甲氧基苯换成辛氧基苯, 设计合成了一系列以三苯胺为给体、辛氧基苯取代的吡啶并[3,4-b]吡嗪为辅助受体、噻吩(呋喃、苯)为π-链、氰基乙酸为受体的新型染料敏化剂(OPP-I～Ⅲ). 对OPP-I～Ⅲ的光电化学性质、器件性能以及电荷转移动力学等进行了系统的测试及研究. 实验结果表明, 用辛氧基取代甲氧基, 能有效减少染料在TiO₂表面的聚集, 同时能阻止电解质和TiO₂导带的接触, 抑制电荷复合, 提高了开路电压. 最后, 在AM 1.5(100 mW·cm^-2)光强条件下, OPP-I敏化的电池最大光电转换效率为 6.57%(短路电流为 11.7 mA·cm^-2, 开路电压为 717 mV, 填充因子为 0.78).     

Synthesis of Pyrazolo[3,4-b]- and Pyrido[2,3-b]-1,5-benzodiazepines

Abstract

3-Dimethylaminomethyleno-4-phenyl-1H-1,5-benzodiazepin-2-one (1) was synthesized and reacted with hydrazines, active nitriles, and amino-heterocyclic compounds to give fused heterocyclic compounds 2–14.     

Synthesis and Photovoltaic Properties of Thieno[3,4‐c]pyrrole‐4,6‐dione‐based donor–acceptor Copolymers

Three donor–acceptor (D–A) 1,3‐di(thien‐2‐yl)thieno [3,4‐c]pyrrole‐4,6‐dione‐based copolymers, poly{9,9‐dioctylfluorene‐2,7‐diyl‐alt‐1,3‐bis(4‐hexylthien‐2‐yl)‐5‐octylthieno[3,4‐c]pyrrole‐4,6‐dione}, poly{N‐(1‐octylnonyl)carbazole‐2,7‐diyl‐alt‐1,3‐bis(4‐hexylthien‐2‐yl)‐5‐octylthieno[3,4‐c]pyrrole‐4,6‐dione}, and poly {4,8‐bis(2‐ethylhexyloxyl) benzo[1,2‐b:3,4‐b′]dithiophene‐alt‐1,3‐bis(4‐hexylthien‐2‐yl)‐5‐octylthieno[3,4‐c] pyrrole‐4,6‐dione} were synthesized by Suzuki or Stille coupling reaction. By changing the donor segment, the bandgaps and energy levels of these copolymers could be finely tuned. Cyclic voltammetric study shows that the highest occupied molecular orbital (HOMO) energy levels of the three copolymers are deep‐lying, which implies that these copolymers have good stability in the air and the relatively low HOMO energy level assures a higher open‐circuit potential when they are used in photovoltaic cells. Bulk‐heterojunction photovoltaic cells were fabricated with these polymers as the donors and PC₇₁BM as the acceptor. The cells based on the three copolymers exhibited power conversion efficiencies of 0.22, 0.74, and 3.11% with large open‐circuit potential of 1.01, 0.99, and 0.90 V under one sun of AM 1.5 solar simulator illumination (100 mW/cm²). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Novel phenanthrocarbazole based donor–acceptor random and alternating copolymers for photovoltaics

A series of 6H‐phenanthro[1,10,9,8‐cdefg]carbazole (PC) and benzothiadiazole (BT) based donor–acceptor (D‐A) random copolymers PPC‐T‐BT_3/1, PPC‐T‐BT_2/1, PPC‐T‐BT_1/1, PPC‐T‐BT_1/2, and PPC‐T‐BT_1/3 were easily prepared by varying the molar ratio of PC to BT from 3:1, 2:1, 1:1, 1:2, to 1:3, respectively. The corresponding alternating D‐A copolymer poly{6H‐phenanthro[1,10,9,8‐cdefg]carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole} (PPCDTBT) was also synthesized for comparison. Compared with PPCDTBT, PPC‐T‐BT_1/1, PPC‐T‐BT_1/2, and PPC‐T‐BT_1/3 obtained more pronounced intramolecular charge transfer band and extended absorption. Power conversion efficiency of these copolymer‐based devices strongly depends on the D/A molar ratio, related to the spectrum absorption and active layer morphology. Among the polymer solar cells based on random copolymers, PPC‐T‐BT_2/1:PC₆₁BM based device achieved the best efficiency of 1.9%, which is close to the efficiency of PPCDTBT:PC₆₁BM based device (2.3%). Therefore, it is concluded that the random copolymer can achieve the comparable performance to alternating copolymer by precisely adjusting the D/A molar ratio on small scales. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4885–4893