苯并䓛盘状液晶:合成、柱状相和光物理性质

盘状液晶分子由稠环芳核和围绕的多条柔性链构成, 具有独特的自组装有序超分子结构、半导体性质和光学性质. 其可通过溶液或喷墨打印技术加工成为光电子薄膜器件, 具有低成本优势. 通过Suzuki-Miyaura交叉偶联和Scholl氧化环化策略, 合成了一系列新的具有苯并䓛结构的非对称酸酐、羧酸酯、酰亚胺和苯并咪唑稠环衍生物, 并对其液晶性和光物理性质进行了详细研究. 通过偏振光学显微镜(POM), 差示扫描量热法(DSC)和小角度X射线散射(SAXS)测试表明, 这些极性盘状化合物自组装堆积呈六方柱状(Col_hex)液晶相, 其中, 最宽的液晶温度范围达206 ℃. 官能团和共轭体系大小决定了相变温度和液晶范围. 荧光测试结果表明, 化合物溶液中绝对量子产率高达34%, 根据官能团不同, 这些化合物发蓝、绿和红光. 借助密度泛函理论(DFT)计算, 解释了该系列极性盘状液晶分子发光性质的差异. 基于本工作的合成方法, 从萘酸酐原料出发为构建结构多变、性质丰富的π-共轭(杂环)芳烃盘状液晶化合物提供了新途径.     

Cations and Anions of Dibenzo[a,e]pentalene and Reduction of a Dibenzo[a,e]pentalenophane

Dibenzo[a,e]pentalene (DBP) is a non-alternant conjugated hydrocarbon with antiaromatic character and ambipolar electrochemical behavior. Upon both reduction and oxidation, it becomes aromatic. We herein study the chemical oxidation and reduction of a planar DBP derivative and a bent DBP-phane. The molecular structures of its planar dication, cation radical and anion radical in the solid state demonstrate the gained aromaticity through bond length equalization, which is supported by nucleus independent chemical shift-calculations. EPR spectra on the cation radical confirm the spin delocalization over the DBP framework. A similar delocalization was not possible in the reduced bent DBP-phane, which stabilized itself by proton abstraction from a solvent molecule upon reduction. This is the first report on structures of a DBP cation radical and dication in the solid state and of a reduced bent DBP derivative. Our study provides valuable insight into the charged species of DBP for its application as semiconductor.     

Preparation and Properties of Cyclopalladated Complexes of Dibenzo[a,c]phenazine and Dibenzo[f,h]quinoxaline with Ethylenediamine

Russian Journal of General Chemistry -     

新型苯并香豆素醛的设计合成及光物理性质研究

设计合成了具有较长发射波长的苯并香豆素醛--8-二乙氨基-2-氧-2H-苯并香豆素醛(BCA),通过吸收和荧光光谱研究其在不同溶剂中的光物理性质.结果表明,BCA具有明显的溶致变色效应和宽的颜色变化范围.随着溶剂极性的增加,其荧光发射可从蓝绿光变到红光,而荧光量子效率则从0.98减小到0.26.     

Benzo[f]-3-aza- and -10-azafluoroanthenes

Reduction of 3-methyl-9-(o-tolyl)-2-azafluoren-9-ol (I) with tin in hydrochloric acid gave 3-methyl-9-(o-tolyl)-2-azafluorene, dehydrocyclization of which on a K-16 catalyst at 520–500°C gave a complex mixture, from which four substances — 2-methylbenzo[f]-3-azafluoranthene, 11-methylbenzo[f]-10-azafluoranthene, benzo[f]-3-azafluoroanthene (II), and I-were isolated and identified by means of the IR, UV, and PMR, and mass spectra. It is shown that the dehydrocyclization proceeds through the hydrogen atoms of the methyl group of the tolyl substituent and takes place at the 8-C or 1-C atom of the azafluorene system. The formation of products II and I constitutes evidence that the reaction is accompanied by partial demethylation or oxidation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1245–1247, September, 1977.     

Electronic absorption spectra of pseudoazulenes — Benzo[b]cyclopenta[e]pyran derivatives

Benzo[b]cyclopenta[e]pyran derivatives were synthesized, and their electronic absorption spectra were recorded. The absorption spectra were calculated by the Pariser-Parr-Pople method. The absorption bands in the spectra of the synthesized compounds were assinged on the basis of an anlysis of the experimental and calculated values obtained in the study. It is shown that the long-wave transition in the spectra of benzo[b]cyclopenta[e]pyrans is realized through charge transfer from the five-membered ring to the six-membered heteroring and is determined to a great degree by the pronounced delocalization of the C-C bonds in the fulvene fragment on passing to the first excited state. The bathochromic shift of the long-wave band when phenyl and styryl substituents are introduced is due to the increase in the energy of the upper occupied molecular orbital as compared with the virtual invariability of the level of the lower vacant molecular orbital.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1329–1334, October, 1978.     

新型非对称二苯并[b,f][1,5]二氮杂环辛四烯的合成

以两种不同取代的2-氨基二苯甲酮为原料,氯苯为溶剂,BF3-Et2O为脱水剂,通过分子间脱水一步环化缩合制备非对称二苯并[b,f][1,5]二氮杂环辛四烯衍生物。运用HPLC监控反应过程,优化合成工艺,得到最佳反应条件为:等物质的量的两种不同取代2-氨基二苯甲酮和BF3-Et2O,在氯苯中回流反应12 h。化合物4a^4c为新化合物,其结构经1H NMR,13C NMR和MS(ESI)表征。     

二苯并[b,f][1,5]二氮杂芳辛四烯衍生物的合成及拆分

以邻氨基二苯甲酮为原料,经自身缩合环化合成了3种二苯并[1,5]二氮杂芳辛四烯衍生物(1a~1c);以邻苯二甲酸酐和溴苯为原料经傅-克反应制得中间体2-(4-溴苯甲酰溴)苯甲酸(M1);M1经叠氮化后自缩合制得6,12-二(4-溴苯基)二苯并[b,f][1,5]二氮杂环辛四烯(1d);以邻氨基苯甲酸甲酯为原料,经自身缩合环化制得中间体二苯并[b,f][1,5]二氮杂环辛四烯-6,12(5H,11H)-二酮(M2);M2经氯化合成6,12-二氯二苯并[b,f][1,5]二氮杂环辛四烯(1e),化合物1a~1e的结构经~1H NMR,~(13)C NMR和ESI-MS表征,其中化合物1c为新化合物。利用超临界色谱(SFC)技术对化合物1a~1e实现了手性拆分,获得5对具有高旋光度的光学活性异构体(ee99%)。     

Optical Resolution of Dibenzo[a,g]fluorenol via Glycosylation

A simple optical resolution of dibenzo[a,g]fluorenol has been accomplished via borontrifluoride‐mediated Ferrier rearrangement reaction.     

Phenanthrene-fused azo-ene-ynes: synthesis of dibenzo[f,h]cinnoline and dibenzo[e,g]isoindazole derivatives

The cyclization reactions of a phenanthreno-fused azo-ene-yne compound have been studied both experimentally and computationally. Experimental results show that this system is prone to dimerization, more so than previously studied naphthalene- and benzene-based analogues. Calculations reveal that pyrazoles and arene-fused pyrazoles strongly stabilize carbenes in the 5-position through "coarctate conjugation", suggesting a stationary concentration of the carbenes/carbenoids during cyclization that is high enough for dimerization.     

Syntheses and Crystal Structures of Pyridyl Substituted Dibenzo[b,e]-[1,4]diazepin-1-one Derivatives

A new series °f 11-pyridyl substituted dibenz°-diazepin-1-°ne derivatives 1 was synthesized by a tw° step cycl°c°ndensati°n reacti°n. All the c°mp°unds were characterized by IR,MS, and 1H NMR. And crystals °f 1a and 1b were °btained and determined by X-ray single-crystal diffracti°n. Crystal data °f 1a: C48H52N6O7, m°n°clinic system, space gr°up C2/c, a = 28.39(4), b =9.275(12), c = 16.84(2) A, β = 104.98(3)°, V = 4284(10) A3, Z = 4, F(000) = 1752, Dc = 1.279 g/cm3,R = 0.0603, and wR = 0.1314. Crystal data °f 1b: C24H21N3 O, m°n°clinic system, space gr°up P21/c,a = 11.625(5), b = 19.055(9), c = 8.741(4) A, β = 95.547(6)°, V = 1927.2(15) A3, Z = 4, F(000) =776, Dc = 1.266 g/cm3, R = 0.0494, and wR = 0.1287.     

Benzo[b]tellurophene, Dibenzo[b,d]tellurophene, and Their Derivatives. (Review)

Data on the synthesis, reactions, crystal structure, and spectral characteristics of benzo[b]tellurophene, dibenzo[b,d]tellurophene, and their derivatives are reviewed and analyzed.