X—ray Study on the Ring—substituted Phthalocyanines：Crystal Structure of Metal Free,1,4,8,11,15,18,22,25—Octa—butyloxyphthalocyanine

<正>The crystal structure of 1,4,8,11,15,18,22,25-octa-butyloxyphthalocyanine was determined by X-ray diffraction methods. The crystal is of triclinic, space group P 1 with a = 14.0780(3), b = 14.3480(4), c = 17.0090(2) A, α = 72.156(2), β = 86.193(2), r= 73.655(2)°, C64H82N8O8, Mr = 1091.38, Z = 2, V = 3137.5(1) A3, Dc= 1.155 g/cm3, F(000) = 1172, μ(MoKα) = 0.077 mm-1, the final R = 0.0787 and wR = 0.2240 for 5795 observed reflections with I ≥ 2σ(I). The steric congestion between the neighboring butyloxy groups distorts the core of phthalocyanine into a saddle shape conformation. In the crystal lattice, molecules overlap to each other with π-π interaction but the extent of overlap is different along the three axial directions.     

取代酞菁金属配合物的结构研究进展

结合本研究组的工作, 简要总结了迄今文献上所发表的取代酞菁金属配合物的结构研究结果, 包括四取代、八取代、十六取代、内环取代以及不等同取代等。     

苯并菲盘状液晶的合成、亲氟效应及分子对称性对介晶性的影响

New symmetrical and asymmetrical triphenylene-containing discotic liquid crystals with two different peripheral alkyl chains, known as sym-TP(OC6H13)3(OR)3 and asym-TP(OC6H13)3(OR)3, were synthesized. Their thermotropic liquid crystal properties were investigated through polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses. The asyrranetdcal discogens are 2,6,11-rialkoxy-3,7,10-trihexyloxytriphenylenes, with the alkyl chain carbon numbers varying from 3-10, 12, and 14, while the symmetrical compounds are 2,6,10-trialkyloxy-3,7,11-trihexyloxytriphenylene. Two fluoroalkoxy substituted triphenylene discogens, 2,6,10-td(4,4,4-trifluorobutoxy)-3,7,11-trihexyloxytriphenylene and its asymmetrical isomer 2,6,11-tri(4,4,4-trifluorobutoxy)-3,7,10-trihexyloxytdphenylene were prepared. These two compounds show higher melting and clearing points than their alkoxy analogs, which implies that fluorophilic effect exists in the formation and stabilization of discotic columnar mesophase. The triphenylene derivatives TP(OC6H13)3(OR)3 with two different peripheral chains, symmetrically or asymmetrically attached on triphenylene cores, have lower melting points and clearing points than those of the higher symmetrical compounds TP(OR)6 with the same total chain carbon numbers. The mixed-chain-triphenylenes with longer alkoxy chains (n=9,10,12,14) show columnarmesophase at room temperature.     

Synthesis of Mixed Tail Triphenylene Discotic Liquid Crystals： Molecular Symmetry and Oxygen-Atom Effect on the Stabilization of Columnar Mesophases

Small change in chemical structure of discotic liquid crystals can cause big difference in their mesomorphism. Replacing of the alkoxy peripheral chains of triphenylene by oxygen-atom containing ester chains would result in novel mesomorphism. A series of mixed tail triphenylenes containing propoxyacetyloxy and alkoxy, abbreviated as C18H6（OCnH2n＋1）3（OCOCH2OC3H7）3, n=4-8, and hexa（propyloxyacetyloxy）triphenylene, C18H6（OCOCH2OC3H7）6 were synthesized. Thermal gravimetry analysis （TGA） of three discogens showed that they had good thermal stability till 350 ℃. The mesomorphism was investigated through differential scanning calorimetry （DSC） and polarized optical microscopy （POM）. The preliminary X-ray diffraction （XRD） results of one compound showed that it exhibited ordered hexagonal columnar （Colho） mesophase. These mixed tail triphenylene derivatives possessed much stable Colho mesophase and wider mesophase ranges than their hexaalkoxytriphenylene C18H6（OR）6 and hexaalkanoyloxytriphenylene C18H6（OCOR＇）6 analogues. The asymmetrical compounds 2,6,11-trialkoxy-3,7,10-tri（2-propyloxyacetyloxy）triphenylenes with n=5-8 displayed higher clearing points and wider temperature ranges than their symmetrical isomers 2,6,10-trialkoxy-3,7,11-tri（2-propyloxyacetyloxy）- triphenylenes, while C18H6（OCOCH2OC3H7）6 had the highest clearing point due to the β-oxygen-atom effect.     

新的混合柔链苯并菲盘状液晶：分子对称性与宽温柱状介晶相

A series of new trialkoxytrialkanoyloxytriphenylene TP（OCnH2n＋1）3（OCOCmH2m＋1）3 （5a-5e） （n =m＋1 =4- 8） discotic liquid crystals were prepared and their mesomorphic properties were investigated using differential scanning calorimetry （DSC） and polarizing optical microscopy （POM）. The symmetrical and shorter chain triphenylenes display higher melting points and clearing points, more highly ordered and stable columnar mesophase than the asymmetrical and longer chain triphenylenes respectively.     

Maximum Overlap Symmetry Molecular Orbital Calculation under CNDO／2 Approximation

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用SymApps与Weblab-ViewerPro研究分子的对称性

介绍了使用化学软件SymApps与Weblab-ViewerPro研究分子对称性的方法。给出了研究分子点群和分子手性，并快速制作对称操作三维动画的实例。     

VRML在分子对称性教学中的应用

以椅式环己烷为例,介绍了如何应用分子模拟软件制作含有分子对称元素的VRML模型的过程。利用VRML的交互性可以帮助学生直观地掌握分子的三维结构以及对称元素的分布,切实提高了分子对称性的教学效果。     

End-capped Thiophene Modulated Molecular Packing in 2,8-Dibenzothiophene-based Materials：from Face-to-face to Edge-to-face Stacking

Two new organic crystals of 2,8-bisthienyldibenzothiophene(BTDT) and 2,8-bis-dithienyldibenzothiophene(BDTDT) compounds were successfully obtained.The change of end-capped group from thiophene to dithiophene causes big differences in molecular packing and carrier-transport property.The adjacent molecules of compound BTDT adopt face-to-face π stacking and exhibit two-dimensional interchain interactions.On the contrary,BDTDT molecules are arranged in an edge-to-face motif and show mainly one-dimensional interacting character.The packing mode exerts dramatic effect on the carrier-transport property.The crystal of BTDT belongs to the orthorhombic system,space group P21212 with a = 20.1427(11),b = 4.6016(3),c = 8.6340(5) ,V = 800.27(8) 3,Z = 2,Dc = 1.446 g/cm3,F(000) = 360,S = 1.019,the final R = 0.0491 and wR = 0.0960 for 1605 reflections with I > 2σ(I).The crystal of BDTDT belongs to the orthorhombic system,space group P212121 with a = 7.2636(15),b = 25.359(5),c = 25.359 ?,V = 4670.9(14) ?3,Z = 8,Dc = 1.458 g/cm3,F(000) = 2112,S = 0.880,the final R = 0.0597 and wR = 0.1318 for 8047 reflections with I > 2σ(I).     

POV-Ray软件在分子对称性中的应用

以交错式乙烷为例,详细地介绍了如何使用POV-Ray软件制作展示分子对称元素的精美视频动画,可以帮助学生直观形象地分析分子结构,很好地掌握分子对称性的相关教学内容,切实提高课程的教学效果。     

General Formulations of Finite-field Method Classified by Symmetry for Molecular Linear and Nonlinear Polarizabilities

1 INTRODUCTIONWith the invention of lasers[1] and the observation of second-harmonic generation in quartz[2], nonlinear optics(NLO), as a cornerstone of photonics, has been booming since 1960's. And intense interest has been aroused to search materials exhibiting appropriate nonlinear optical properties suitable for the construction of practical optical devices for the important techniques such as frequency converting, signal processing and optical computing[3～6]. In order to determine …     

金属酞菁催化脱羧合成3,4-二烷氧基噻吩的简便方法

以金属酞菁为催化剂,2,5-二羧酸-3,4-二烷氧基噻吩在水相中脱羧,以较高的产率和纯度制得3,4-二烷氧基噻吩,避免了有机极性溶剂的使用,催化剂重复使用8次仍表现出优异的催化性能.另外,通过简易的水蒸气蒸馏法即可分离出产物.该法具有环境友好、操作简易和反应时间短等优点,是一种制备3,4-二烷氧基噻吩的绿色方法.     

Prevalence and Significance of Approximate Symmetry in Organic Pc Structures

A survey has been made of the well determined (R≤0.050) organic crystal structures that have only a single glide plane (e. g., are in space group Pc) and that have more than one crystallographically independent formula unit (Z′>1); the goal was to discover what fraction have additional approximate symmetry. Of the 377 unique structures examined 8 % should almost certainly been refined in a higher-symmetry unit cell; 86 % of the remaining 347 have approximate symmetry that is periodic in at least one dimension. While these percentages are similar to those found for P1 structures (C. P. Brock, Acta Crystallogr., Sect. B 2022 , 78, 576–588), the types of approximate symmetry differ because 89 % of the P1, Z′>1 structures were composed of enantiopure material. The 347 reliable Pc structures include 118 that are slightly distorted or mimicked Cc and P2₁/c structures, 15 of which were reported as having been determined at room temperature. The distortions in another 72 are so large that the approximate symmetry must be seen as periodic in two dimensions only. These results suggest that symmetry lowering may accompany transformation of a crystal nucleus to a macroscopic crystal.     

定域分子轨道对称性

提出了利用定域分子轨道重心确定分子轨道的对称性。确定了线型的、非线型的、环状的分子定域分子轨道对称性。结果表明非线型分子和其中双中心键具有相同对称性,但含孤对或三中心键的分子则存在一些差别。还讨论了定域分子轨道的特征。     

手性酞菁的合成及其绝对构型

在锂存在的条件下在正戊醇中回流环化四聚相应的光学活性的前驱体联二萘[2,1-e:1',2'-g][1,4]二羟基-5,6-邻苯二氰, 然后用醋酸酸化处理, 合成了一对对映的四个联二萘酚基团取代的手性自由酞菁四(联二萘[1,2-e:1',2'-g]-1,4-二羟基)[2,3-b;2',3'-k;2',3'-t;2'',3''-c']酞菁(1), 并利用一系列的光谱学方法以及元素分析表征了这种新型的手性酞菁化合物. 单晶X衍射分析确定了两种对映体的绝对构型, 从而阐明了自由酞菁(1)的手性分配.     

Molecular images of [M(phthalocyaninato)O]n,where M = Si and Ge: Microphases and structures of crystal domains

This contribution is a study of the crystal structures and crystal domains in the thin epitaxially growing films of [M(Pc)O]n (M = Si and Ge, Pc = phthalocyaninato) revealed by high-resolution electron microscopy. Microphases detectable only on the microscopic level were observed: (a) γ-phase for [Si(Pc)O]n, orthorhombic system, a = 1.38 nm, b = 5.52 nm, c = 0.66 nm; and (b) α-phase for [Ge(Pc)O]n, base-centered orthorhombic, a = 1.33 nm, b = 2.66 nm, c = 0.35 nm. Translation and rotation crystal domains were visualized on the nanometeric scale. The high-resolution images are rich in irregularity and provide direct information on the defects and imperfections in the polymer films. © 1995 John Wiley & Sons, Inc.     

A Symmetry adapted tessellation of the GEPOL surface: applications to molecular properties in solution

A procedure to partition the GEPOL molecular surface into tesserae that respects the molecular symmetry constraints is presented. Using this method it is possible to build a solvent reaction field for the Polarizable Continuum Model with the same symmetry of the nuclear potential. Several applications are reported and discussed to evaluate the performance of this new procedure. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1262–1272, 2001