新型低聚噻吩衍生物的设计、合成及其液晶性能的研究

设计、合成了一系列新型低聚噻吩衍生物N,N’-双烷烃基-5,5’-二溴基-2 ,2’：5’,2’-三噻吩-4,4’-二酰胺[N,N’-dialkyl-5,5’-dibromo-2,2’:5 ’,2’-terthiophene-4,4’-dicarboxamide](DNCnDBr3T,n=5,8,6,18)。示差扫描 量热法（DSC）测定的结果及偏光光学显微镜观察的结果显示,DNC18DBr3T, DNC16DBr3T,DNC8DBr3T具有近晶A形液晶性质,DNC5DBr3T不具有液晶性质。为了探 讨分子间氢链对液晶形成的影响,设计、合成了新型低聚噻衍生物4,4“-双烷烃 酯-5,5“-二溴基-2,2’:5’,2’-三噻吩[4,4’-bis(alkyloxycarbonyl)-5,5’ -dibromo-2,2’:5’,2’-terthiophene](DOCnDBr3T,n=5,8,16,18).测定和观察的 结果发现,DOCnDBr3T(n=5,8,16,18）不具有液晶的结果。这个结果表明,酰胺基 的存在于液晶的形成起着重要的作用。测定DNC18DBr3T在结晶状态和液晶状态下的 红外光谱,进一步证实了部分分子间氢键对于液晶的形成起着重要的作用。     

齐聚噻吩衍生物电致变色性质

合成了四种齐聚噻吩衍生物：5,5"-二氰基-2,2’:5’,2"-三噻吩 (DCN3T), 5,5"’-二氰基-2,2’:5’,2":5",2"’-四噻吩 (DCN4T), 5,5"’-甲氧基-2,2’:5’,2":5",2"’-四噻吩(DMO4T) 和 4,4"-二羧基-5,5"-二丙基-2,2’:5’,2"-三噻吩 (BP3T-DCOOH),研究了它们的电致变色性质,研究结果发现,这四种齐聚噻吩衍生物膜在电场作用下,可以发生可逆的颜色变化。     

水溶性共轭聚电解质的制备及在有机电致变色器件中的应用

制备了聚噻吩电解质聚[3-(1'-丙氧基-3'-磺酸)噻吩](PTH-n₃-SO₃H). 以铂线和ITO玻璃作为电极, PTH-n₃-SO₃H的水溶液作为支持电解质, 分别以齐聚噻吩衍生物5,5"'-双醛基-2,2': 5',2": 5",2"'-四噻吩(4T-2CHO)和5,5"'-双氰基-2,2': 5',2": 5",2"'-四噻吩(4T-2CN)薄膜作为电致变色活性层, 组装了有机电致变色器件. 研究了4T-2CHO和4T-2CN的电致变色性能, 同时考察了PTH-n₃-SO₃H水溶液作为支持电解质在有机电致变色器件中的应用. 研究发现, 当进行电化学掺杂和去掺杂时, 4T-2CHO膜发生从黄色到蓝绿色的可逆变化, 4T-2CN膜发生从淡黄色到蓝色的可逆变化. 结果表明, PTH-n₃-SO₃H水溶液可以作为支持电解质用于有机电致变色器件.     

新型寡聚噻吩的设计、合成及其光物理和电化学性质

以3,4-二溴噻吩为底物,经6步反应设计并合成了以烷基噻吩为共轭骨架,二氰基罗丹明为封端基团的两种新型寡聚噻吩(DC5T和DC7T),其结构和性能经¹H NMR, ¹³C NMR, UV-Vis, MS和CV表征。结果表明：DC5T和DC7T均在400~750nm有较强吸收,吸收边界分别位于732nm和740nm。此外,两种新型寡聚噻吩均具有较深的最高占据分子轨道（HOMO）能级。      

不同取代位置的萘衍生两亲分子在气/液界面组装膜中的螺旋结构与圆偏振发光

Langmuir-Blodgett(LB)技术可在二维气/液界面上精确地控制分子之间的排列及堆积方式, 构建有序超薄膜及纳米组装体. 同时, 界面这一不对称环境也可有效放大组装体的手性信息, 实现超分子体系中的手性传递和手性放大. 本文研究了萘环取代位置不同的两种手性两亲分子——N,N′-双十八烷基-α-萘-L-氨基-谷氨酸二酰胺(1NLG)和N,N′-双十八烷基-β-萘-L-氨基-谷氨酸二酰胺(2NLG)在气/液界面的铺展及组装行为, 发现同分异构效应影响了两亲分子在界面的排列, 1NLG组装形成了均一的纳米带状结构, 而2NLG则形成了左手螺旋结构, 并且2NLG薄膜表现出圆偏振发光(CPL)性质, 其不对称因子(g_lum)比三维体相组装体(超分子凝胶)大23倍, 表明界面促进了超分子手性的放大.     

不良溶剂诱导全聚合物太阳能电池活性层的表面功函变化

使用甲醇溶剂熏蒸聚(4,8-双[5-(2-乙基己基)噻吩-2-基]苯并[1,2-b;4,5-b']双噻吩-2,6-双基-{4-(2-乙基己基)-3-氟代噻吩[3,4-b]噻吩-}-2-羧基-2,6-双基)(PTB7-Th)和聚[N,N'-双(2-辛基十二烷基)-1,4,5,8-萘二酰亚胺-2,6-双基-并-5,5'-(2,2'-双噻吩)](N2200)二元混合的活性层薄膜,发现其活性层和镀金探针间的接触电势差从37 m V升高到160 m V,表明活性层表面功函由4.71 e V降低到4.59 e V.XPS结果表明,由于甲醇和N2200之间更强的相互作用,在溶剂熏蒸过程中有更多的N2200分子扩散到薄膜表面.扩散引起了活性层表面功函的减小,使活性层和电极之间能级更加匹配,形成了更好的欧姆接触,使器件的功率转化效率提高了10%以上.     

基于二噻吩并吡咯π桥的窄带隙非富勒烯受体材料在有机太阳能电池中的应用

以不同烷基取代的二噻吩并吡咯(DTP)为π桥,连接吲哒省并二噻吩(IDT)中间单元和氰基茚酮(IC)或二氟代氰基茚酮(2F-IC)末端基团,设计并合成了6个窄带隙的非富勒烯受体材料。 其中,IDTDTP-C₂C₂-H和IDTDTP-C₂C₂-F中的DTP单元以1-乙基丙基为侧链,IDTDTP-C₆C₆-H和IDTDTP-C₆C₆-F中的DTP单元以1-己基庚基为侧链,IDTDTP-C₁₂-H和IDTDTP-C₁₂-F中的DTP单元以十二烷基为侧链。 6个分子均具有较窄的光学带隙(1.37~1.44 eV)。 相比于以IC为末端基团的分子(IDTDTP-C₂C₂-H、IDTDTP-C₆C₆-H和IDTDTP-C₁₂-H),由于氟原子的拉电子效应,以2F-IC为末端基团的分子(IDTDTP-C₂C₂-F、IDTDTP-C₆C₆-F和IDTDTP-C₁₂-F)具有红移的吸收光谱,以及更低的最高分子占有轨道能级(HOMO)和最低分子空轨道(LUMO)能级。 以宽带隙聚合物聚[2,6-(4,8-双(5-(2-乙基己基))噻吩-2-基)-苯并[1,2-b:4,5-b']二噻吩-alt-5,5-(1',3'-二-2-噻吩)-5',7'-双(2-乙基己基)-苯并[1',2'-c:4',5'-c']二噻吩-4,8-二酮](PBDB-T)为给体材料,制备了有机太阳能电池器件。 PBDB-T:IDTDTP-C₆C₆-F共混薄膜具有较高且更平衡的空穴/电子迁移率,以及良好的形貌,基于PBDB-T:IDTDTP-C₆C₆-F的有机太阳能电池获得了6.94%的能量转换效率,开路电压为0.86 V,短路电流密度为13.56 mA/cm²,填充因子为59.5%。     

新型基于二氟苯并噻二唑和双噻吩丙烯腈共轭聚合物的设计、合成及光伏性能

设计并合成了两种基于5,6-二氟苯并噻二唑和双噻吩丙烯腈单元的D-A型共轭聚合物,聚[(5,6-二氟-苯[c][1,2,5]噻二唑-4,7-基)-交替-((E)-2,3-双(3'-(2-辛基十二烷基)-(2,2'-双噻吩)-5,5'-基)丙烯腈)](DFBT812)和聚[(5,6-二氟-苯[c][1,2,5]噻二唑-4,7-基)-交替-((E)-2,3-双(3'-(2-癸基十四烷基)-(2,2'-双噻吩)-5,5'-基)丙烯腈)](DFBT1014)作为聚合物太阳电池的给体材料。通过侧链工程,引入了2-辛基十二烷基和2-癸基十四烷基侧链实现对聚合物的溶解性,结晶性以及共混膜形貌的调节。研究结果表明,共轭聚合物DFBT812与PC_(61)BM的共混膜表现出更好的相分离尺度,能够促进载流子的传输和抽取。基于共轭聚合物DFBT812的太阳电池器件取得了0.87 V的开路电压和6.25%的能量转换效率。除此之外,基于DFBT812的聚合物太阳电池器件在活性层厚度为220 nm时仍然表现出6%的能量转换效率。     

新型六[间-(β-噻吩基)苯基]苯衍生物的合成

3,3’-二溴二苯乙炔与β-噻吩频哪醇硼酸酯发生Suzuki偶联反应制得3,3’-二(2,5-二十二烷基-3-噻吩)二苯乙炔(7);Co2(CO)8催化7自身环三聚合成了新型六[间-(β-噻吩基)苯基]苯衍生物——六{3-[2’,5’-二(十二烷基)-3-噻吩]苯基}苯,产率86%,其结构经1H NMR和MS表征。     

二噻吩衍生物的合成及其线性、非线性光谱性质

合成了一系列二噻吩衍生物类有机合物：5，5'-二（对－N，N－二甲胺基苯乙 烯基）－2，2'－二噻吩（BMSBT）与5，5'－二（对－N，N－二乙胺基苯乙烯基）- 2,2'-二噻吩（BESBT），5,5'-二（对N－环丁胺基苯乙烯基）－2,2'－二噻吩（ BBSBT），5,5－二（对－N－咔唑基苯乙烯基）2-2'－二噻吩（BCSBT），并测定了 其吸收光谱、单光子荧光光谱和双光子荧光光谱。BMSBT，BESBT和BBSBT的单光子 荧光参数存在的很强的、规则的溶剂效应，表明其激发态的分子可能有较大的极性 。在800nm fs激光下测得BMSBT与BESBT在560nm附近（与单光子荧光发射峰波长接 近的位置）有较强的上转换荧光发射，上转换荧光强度与激发能量之间较好的平方 关系表明了双光子激发的机理，这种上转换荧光被称为双光子荧光。用以光子荧光 法测得BMSBT和BESBT的双光子吸收截面分别为54*10~(-50)(cm~4·s)/photon和 102*10~(-50)(cm~4·s)/photon。     

Creation of Functional Organic Gels Based on Oligothiophenes

Polymer gels have received a great deal of attention not only from scientific interest but also for their practical applications. Recently, low molecular-weight organic gels have also been receiving growing attention. However, their have been few studies of low molecular-weight organic gels in contrast to extensive studies of polymer gels. In order to develop a novel class of low-molecular-weight organic gels and to gain an insight into the relationship between molecular structures of gel-form…     

Synthesis and mesogenic properties of a novel family of oligothiophene derivatives

With the aim of developing new oligothiophene-based liquid crystals involving hydrogen bonding, new terthiophene derivatives containing an alkylamide group, N,N'-distearyl-2,2' : 5',2"-terthiophene-5,5"-dicarboxamide (DNC₁₈3T) and N,N'-dialkyl-5,5"-dibromo-2,2' : 5',2"-terthiophene-4,4"-dicarboxamides (DNC_nDBr3T, n = 5, 8, 16, 18), were designed and synthesized, and their thermal behaviour examined. While DNC₁₈3T did not exhibit liquid crystallinity, DNC_nDBr3T compounds with n = 8, 16, 18 were found to form smectic A phases. In addition to liquid crystal behaviour, crystal polymorphism was also observed for DNC₁₆DBr3T. It is shown that both the position of the amido group and the alkyl chain length greatly affect liquid crystal phase formation. The absence of liquid crystallinity in the corresponding ester derivatives suggests that intermolecular hydrogen bonding also plays a role in the formation of liquid crystal phases in the DNC_nDBr3T system.     

Crystal structure of the 1/ 1 molecular complex of 5,5′,12,12′-bis(triseleno)bis(naphthacene-6,11-quinone) with benzonitrile, (C18H8Se3O2)2(C6H5CN)

The structure of the (C₁₈H₈Se₃O₂)₂(C₆H₅CN) molecular complex isolated from the TSeT + HgI₂ reaction in benzonitrile has been determined. The -Se-Se-Se- fragment has been found to have Se---Se bond lengths equal to 2.348(3) and 2.350(4) Å.     

Esterification of phthalic anhydride with 1-butanol and 2-ethylhexanol catalyzed by heteropolyacids

Esterification of phthalic anhydride with 2-ethylhexanol and 1-butanol and ester decomposition of dioctyl phthalate (DOP) in presence of Keggin; H₃PW₁₂O₄₀, H₄SiW₁₂O₄₀, H₄SiMo₁₂O₄₀, Wells–Dawson; H₆P₂W₁₈O₆₂, H₆P₂W₁₇MoO₆₂ and Preyssler; H₁₄[NaP₅W₂₉MoO₁₁₀], H₁₄[NaP₅W₃₀O₁₁₀], type heteropolyacids have been investigated. The heteropolyacids with Preyssler and Wells–Dawson structures and their molybdenum substituted derivatives show higher activity in esterification and ester decomposition reactions than Keggin type heteropolyacids. A complete conversion of phthalic anhydride to dioctyl phthalate and dibutyl phthalate are achieved in 2 h in presence of molybdenum substituted Preyssler heteropolyacid. In the decomposition of dioctyl phthalate in the presence of Preyssler heteropolyacid, 2-ethylhexene is formed in quantitative yield.     

Amino acid derivatives of cholesterol as "latent" organogelators with hydrogen chloride as a protonation reagent

A series of low molecular weight organic gelator (LMOG) gel systems sensitive to alkaline/acidic stimuli was established by employing amino acid derivatives of cholesterol as "latent" gelators, which are cholesteryl glycinate (1), cholesteryl L-alaninate, cholesteryl D-alaninate, cholesteryl L-phenyl alaninate, and cholesteryl D-phenyl alaninate. The hydrochloric salts are denoted as 2, 3, 4, 5, and 6, respectively. For the 18 solvents tested, one proved to be a weak gelator and gels only two of the solvents. Its gelation ability, however, was greatly improved by bubbling HCl gas, which was produced by reaction of concentrated sulfuric acid with NaCl, through its solution owing to protonation of its amino group. It was demonstrated that the protonated form of it gelled 14 of the solvents tested. Further investigation revealed that the gels changed into solution with addition of any of the amines, including triethylamine (TEA), diethylamine, ethylenediamine, and NH3. The phase transition could be reversed by further introduction of the acidic gas. SEM measurements showed that 1 self-assembled into different supramolecular structures in different gels. Salt effect studies proved that electrostatic interaction is one of the driving forces for formation of the gels.     

Bis(amino acid) oxalyl amides as ambidextrous gelators of water and organic solvents: supramolecular gels with temperature dependent assembly/dissolution equilibrium

Bis(LeuOH) (1a), bis-(ValOH) (2a) and bis(PhgOH) (5a) (Phg denotes (R)-phenylglycine) oxalyl amides are efficient low molecular weight organic gelators of various organic solvents and their mixtures as well as water, water/DMSO, and water/DMF mixtures. The organisational motifs in aqueous gels are dominated primarily by lipophilic interactions while those in organic solvents are formed by intermolecular hydrogen bonding. Most of the gels are thermoreversible and stable for many months. However, 2a forms unstable gels with organic solvents which upon ageing transform into variety of crystalline shapes. For some 1a/alcohol gels, a linear correlation between alcohol dielectric constants (epsilon) and gel melting temperatures (Tg) was found. The 1H NMR and FTIR spectroscopic investigations of selected gels reveal the existence of temperature dependent network assembly/dissolution equilibrium. In the 1H NMR spectra of gels only the molecules dissolved in entrapped solvent could be observed. By using an internal standard, the concentration of dissolved gelator molecules could be determined. In FTIR spectra, the bands corresponding to network assembled and dissolved gelator molecules are simultaneously present. This enabled determination of the Kgel values by using both methods. From the plots of InKgel versus 1/T, the deltaHgel values of selected gels have been determined (-deltaHgel in 10-36 kJ mol(-1) range) and found to be strongly solvent dependent. The deltaHgel values determined by 1H NMR and FTIR spectroscopy are in excellent agreement. Crystal structures of 2a and rac-5a show the presence of organisational motifs and intermolecular interactions in agreement with those in gel fibres elucidated by spectroscopic methods.     

Salt/current-triggered stabilization of β-cyclodextrins encapsulated host-guest low-molecular-weight gels

Host-guest supramolecular gels were developed via the self-assembly of inclusion complexes(ICs) ofβ-cyclodextrins/phenylboronic acid gelator(PBA).Salts and current were involved in the self-assembly to stabilize the host-guest gels.The stability of the gels was greatly improved after salts were added.The stable time of gels was extended from 2.5 h to 120 h with the addition of NH_4 NO_3 at the concentration of 2.5×10^-2 g/mL.The morphology of the gel was affected by the concentrations of NH_4NO_3.SEM images revealed that the gels were three-dimensional nanofibrous networks,the sizes of fibers decreased with decreasing NH_4NO_3 concentrations,which affected the stability of gels,further proved by the rheological properties of gels.More stable gels were obtained with current stimulation,the stable time of the gel was increased from 2.5 h to 55 h with current by adding NaBF_4.The current also exhibited significant influence on the aggregation as the voltage varied(0-500 mV) with a constant concentration of salts.The result showed the self-assembly process of host-guest gel could be well controlled via the addition of salts and current to desired morphology and stability.     

The interstellar gas-phase formation of CO2 – Assisted or not by water molecules?

Using state of the art methods of quantum chemistry, potential energy surfaces for the formation of and CO₂ (³B₂) from CO + O (¹D) and CO + O (³P), respectively, have been studied. At the MRSDCI level, we show that the formation of from O (³P) is strongly connected with the height of the barrier localized on the CO + O (³P) entrance channel. At the CCSD(T) level with a large basis set we calculate this barrier to be 5.9 kcal/mol. Consequently, we confirm that the gas-phase formation of CO₂ in interstellar molecular clouds is inefficient. To mimic the formation of CO₂, through the Eley–Rideal mechanism, on the water ice surfaces of interstellar grains, we have extended our study to consider the formation of CO₂ in the presence of water molecules. We show, using density functional and CCSD(T) methods, that the barrier located on the CO + O (³P) reaction entrance channel is hardly affected by the presence of water molecules. We therefore suggest that CO₂ formation, through the Eley–Rideal mechanism, on the water ice surfaces of interstellar grains, should be inefficient too.     

Analysis by DSC of the drying and sintering processes of alkoxide-derived SiO2–ZrO2 gels

The drying and sintering processes of SiO₂–ZrO₂ alkoxide-derived gels have been studied by means of DSC technique. In the drying process, most part of water and alcohols are removed from the gels. For the SiO₂ gel such elimination occurs at the end of the drying process, however for the ZrO₂ gel this elimination occurs during the whole drying time. An intermediate behavior is observed for the binary system SiO₂–ZrO₂ gels. In the sintering process, the DSC technique allows to determine the elimination of water and alcohols retained within the structure (open or close pores) and the well-known hydroxyl condensation of silica gel between 700° and 800°C is also observed. The ZrO₂ gel shows the final hydroxyl condensation at the heating temperature of 600°C. For the binary SiO₂–ZrO₂ gels, the hydroxyl condensation has been associated to the activation energy needed for the dissociation of silica hydroxyls. This energy decreases with the ZrO₂ concentration in the gel resulting in a sintering treatment of 500°C leading to the entire hydroxyl condensation for the gel with 75% ZrO₂–25% SiO₂.

By studying the temperature of the DSC peaks, it is possible to know the temperature at which most part of water and alcohols are leaving the gel, and these results can be used in order to select the corresponding drying or sintering schedules for obtaining a well-fabricated material.     

NEAR-INFRARED DETECTION OF SINGLET MOLECULAR OXYGEN PRODUCED BY PHOTOSENSITIZATION WITH PROMAZINE and CHLORPROMAZINE

A sensitive near-infrared detection system has been used to study the steady-state emission of ¹O₂ at 1268 nra produced by promazine (PZ) and chlorpromazine (CPZ) during photo-illumination. Singlet molecular oxygen could be detected in a variety of ordinary and perdeuterated organic solvents, but was not detectable in water or deuterium oxide. The emission was enhanced in the perdeuterated organic solvents and could be eliminated by rigorous degassing or by addition of the singlet oxygen scavenger 2,3-dimethylfuran. Singlet oxygen could not be detected in any of the solvents during irradiation of the sulfoxides of PZ and CPZ. We conclude that in biological systems ¹O₂ production is not a major pathway to phototoxicity for the sulfoxides, while for the parent phenothiazines the formation of ¹O₂ is much more likely to be important in nonpolar environments such as cell membranes than in the aqueous parts of the cell.