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1.
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.  相似文献   

2.
The fluorophobic effect of the semi-fluorinated chain of discotic molecules efficiently improves the stability of columnar mesophase.Low symmetric discogens exhibit decreased melting points and wide mesophase ranges.A series of triphenylene derivatives 1,C18H6(OCnH2n+1)4(OMe)(O2CC2H4C6F13),and their hydrocarbon analogues 2,C18H6(OCnH2n+1)4(OMe)(O2CC8H17),n = 4―8,were synthesized for the investigation of the influence of semi-fluorinated peripheral chain and molecular symmetry on mesomorphism.The structures ...  相似文献   

3.
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.  相似文献   

4.
In this work, the mesophase properties were tuned via mixing two discotic molecules with structural complementarity. Compared with the liquid crystalline hexakis(n-hexyloxy)triphenylene(H6TP)materials(columnar hexagonal phase from 53 8C to 91 8C), mesophase types as well as phase transition temperatures varied with the introduction of crystalline hexaazatriphenylene derivative(PBH)molecules. The introduction of less than 33% amount of PBH disrupted the columnar hexagonal phase formed by H6 TP remarkably, followed by the decreased clearing temperatures of liquid crystals. As the PBH amount was further increased, the destroyed columnar hexagonal phase was turned into the columnar rectangular phase, in which H6 TP and PBH molecules together formed the columnar mesophase. The formation of new mesophase contributed to the enlarged mesophase temperature(from44 8C to 144 8C). We speculated that the alkyl chains interaction induced by the PBH component competed with the strong p–p stacking between H6 TP molecules, thus altering the liquid crystalline properties including mesophase types and phase transition temperatures.  相似文献   

5.
Connecting two discotic mesogens via a spacer not only stabilizes the columnar mesophase but also leads to the formation of glass columnar phase, and therefore improves the physical properties of discotic liquid crystals as organic semiconductor. Here, we report the synthesis of eight diacetylene-bridged triphenylene discotic liquid crystal dimers, [C18H6(OCnH2n+1)4(OMe)O2C-C8H16-C≡≡ C-]2, 3(n), (n = 4-8), [C18H6(OC6H13)5O2C-C8H16-C≡≡ C-]2, 6 and [C18H6(OC6H13)5O-(CH2)m-C≡≡ C-]2, 8(m), (m = 1, 3) by Eglinto...  相似文献   

6.
郑世军  Kazuo  Akagi  Qun  Xua  Zi-fa  Li  Shao-kui  Cao  Qi-feng  Zhou 《高分子科学》2006,(3):265-271
Abstract The novel shish-kebab-type liquid crystalline poly(p-phenylene)s were synthesized through Suzuki coupling reaction from 2,5-bis[(4-n-alkoxyl)benzoyloxy]1,4-dibromobenzene (monomer 1) and 1,4-benzenediboronic acid bistrimethylene cyclic ester (monomer 2). Their structure and properties were characterized by GPC, DSC, X-ray diffraction and polarizing optical microscope (POM). It was found that the polymers turned to liquid crystalline phase above their melting point. The melting point (Tm) of the polymers decreases when the length of the alkoxy tails of the mesogenic units increases. The mesophase was identified by X-ray diffraction method. The polymers could dissolve in common organic solvents and show strong blue fluorescence. The maximum absorption bands of polymers prepared from annealed films have large red-shift due to the spontaneous orientation of the liquid crystalline side chains. The same phenomena were also observed in the fluorescence spectra.  相似文献   

7.
To search for more wider absorption and higher charge carriers mobilities materials of polymer solar cell, a series of soluble alternating polyfluorene copolymers were synthesized by palladium-catalyzed Suzuki coupling reaction. Their structures were determined by 1H NMR, IR and UV-vis. And their UV-vis absorption spectra indicated that they had strong absorption over 600 nm spectral range and nearly cover 400-700 nm visible region. The band gaps of copolymers calculated according to cyclic voltammetry (CV) were between 1.96 and 2.03 eV. Polymer:TiO2 bulk-heterojunction films were made from mixtures of polymer and titanium isopropoxide, a precursor for TiO2, via hydrolysis in air overnight. The photoluminescence at 380-800 nm of the blend film of PT-TPP20 (5 mg/mL):Ti(OC3H7)4 (80 μL/mL) (20% volume fraction) was significantly quenched in the 50% Ti(OC3H7)4 blend film, indicating that rapid and efficient separation of photoinduced electron-hole pairs.  相似文献   

8.
The Reaction of Molybdenum with 2,3-Dihydroxynaphthalene   总被引:1,自引:0,他引:1  
[H2N(CH2)3NH312[MoO2(C10H6O2)2] (1) was synthesized by the 2,3-dihydroxynaphthalene in the mixed solvent of CH3OH, CH3CN reaction of (n-Bu4N)4[Mo8O26] with and 1,3-propanediarnine. (C5HllN2)2- [HeN(CH2)3NH2][MoO2(CloH6O2)2] (2) was obtained by the reaction of Na2MoO4.2H20 with 2,3-dihydroxynaphthalene in the same solvent above. Both of the complexes possess complex anion [Mo(VI)O2(OC10H6O)2]^2- which shows pseudo-octahedrally coordinated fashion, while the counterions are two protonated 1,3-propanediamine in complex 1 and (CsH11N2)^+ in complex 2. (C5H11N2)+ is the byproduct of reaction 2, which results from combination of acetonitrile with 1,3-propanediamine. Packing diagrams of the two complexes are also different. There is anti-parallel-aligned-double-meso-bilayer unit in complex 1. However there are four chiral anions arranged in anticlockwise orientation in complex 2.  相似文献   

9.
There are abundant supplies of mixture gases containing CH4, C2H6, C3H8 and C4H10, etc. from FCC (Fluidized Catalytic Cracking) tail gas, refinery gas, etc. Commonly, the mixture gases are primarily combusted to carbon dioxide because the complete separation of CH4, C2H6, C3H8 and C4H10, respectively, from the mixture gases may not be economical. Provided that syngas (CO+H2) could be produced from the mixture gases over nickel supported catalysts with high selectivity and conversion,…  相似文献   

10.
Two vic-dioxime ligands (LxH2) containing morpholine group have been synthesized from 4-[2-(dimethylaminoethyl)] morpholine with anti-phenylchloroglyoxime or anti-monochloroglyoxime in absolute THF at -15 ℃. Reaction of two vic-dioxime ligands with MCl2·nH2O (M: Ni, Cu or Co and n=2 or 6) salts in 1 : 2 molar ratio afforded metal complexes of type [M(LxH)2] or [M(LxH)2·2H2O]. All of metal complexes are non-electrolytes as shown by their molar conductivities (Am) in DMF (dimethyl formamide) at 10^-3 mol·L^-1. Structures of the ligands and metal complexes have been solved by elemental analyses, FT-IR, UV-Vis, ^1H NMR and ^13C NMR, magnetic susceptibility measurements, molar conductivity measurements. Furthermore, redox properties of the metal complexes were investigated by cyclic voltammetry.  相似文献   

11.
陈红梅  赵可清  胡平  汪必琴 《化学学报》2007,65(14):1368-1376
全氟烃链的憎氟效应(fluorophobic effect)可有效地促使棒状分子形成近晶相, 并稳定液晶相. 为进一步探讨氟效应对盘状分子介晶性的影响, 合成了一系列全氟酯链的苯并菲化合物C18H6(OCnH2n+1)5(OCOC2H4C6F13) (a), 以及另一系列相对应的不含氟化合物C18H6(OCnH2n+1)5(OCOC8H17) (b), n=4~9. DSC检测和偏光显微镜观察显示两类化合物都为柱状相热致型液晶. 化合物a与相对应的化合物b比较, 其熔点和清亮点上升, 柱状相的热稳定性增强.  相似文献   

12.
余文浩  赵可清  汪必琴  胡平 《化学学报》2007,65(12):1140-1148
盘状液晶分子能自组装成高度有序的六方柱状介晶相. 其各向异性的载流子高速迁移率使其成为较理想的有机光电子材料. 采用分子间氢键锚定柱状相, 获得介晶相温度范围宽、有序度高的苯并菲盘状液晶是本研究的目的. 本文通过分子设计, 合成了3个系列, 共18个有两种不同软链的苯并菲盘状液晶化合物C18H6(OR)5(OCH2COOEt), C18H6(OR)5(OCH2COOBu)和C18H6(OR)5(OCH2CONHBu), 其中R=CnH2n+1, n=4~9. 化合物的纯度和结构通过1H NMR和元素分析确证. 化合物热稳定性通过热重分析(TGA)测定, 并显示出较高的热稳定性. 通过偏光显微镜(POM)和差示扫描量热法(DSC)对这些化合物的热致液晶性进行了研究. 结果显示对于分子中含有酰胺基的苯并菲液晶化合物C18H6(OR)5(OCH2CONHBu), 与具有同样软链长度的分子中不含酰胺键的化合物系列C18H6(OR)5(OCH2COOBu)相比较, 前者由于柱内分子间氢键的形成, 具有更高的熔点和清亮点.  相似文献   

13.
苯丙炔酸和苯丙烯酸酯苯并菲盘状液晶的合成及介晶性   总被引:2,自引:0,他引:2  
合成了7个含苯丙炔酸和苯丙烯酸酯链的苯并菲盘状液晶化合物C18H6(OCnH2n+1)5O2CR' [R'=C≡CC6H5, n=4~9 (1a1f); R'=CH=CHC6H5, n=6 (1g)]. 该系列化合物结构通过1H NMR, IR和元素分析表征. 液晶性通过差示扫描量热法和偏光显微镜进行了研究, 结果显示: 化合物均为六方柱状相热致型液晶; 含苯丙炔酸酯链苯并菲盘状液晶化合物1a1f, 随着烷氧链的增长, 清亮点呈现逐渐下降的趋势; 对于含苯丙烯酸酯链苯并菲化合物1g与具有同样软链长度的炔基酯链苯并菲化合物1c比较, 具有更低的熔点和结晶点, 而它们的清亮点几乎一致, 因而化合物1g有更宽的介晶性温度范围.  相似文献   

14.
有玻璃态和液晶态的胆甾烯基苯并菲的合成及介晶性   总被引:1,自引:0,他引:1  
宋质琼  赵可清  胡平  汪必琴 《化学学报》2008,66(11):1344-1352
将盘状液晶基元苯并菲与手性向列型液晶基元胆甾烯基结合的化合物, 可望出现全新的性质. 合成了含有胆甾烯基的苯并菲化合物C18H6(OC5H11)5(OC5H10COOCh) (2), 2,7-C18H6(OC5H11)4(OC5H10COOCh)2 (4), C18H6(OR)3(OCnH2nCOO- Ch)3 (R=C5H11, C7H15, C9H19, C11H23, n=1, 5, 10) (6a6f), C18H6(OC5H10COOCh)6 (Ch: cholesteryl) (8). 偏光显微镜和差示扫描量热法对这些化合物的热致介晶性研究结果显示, 化合物 4, 6a6e具有手性盘状向列相和玻璃态, 8呈现近晶B相(SB)和玻璃态. 随间隔基长度n和烷基链R碳原子数的增加, 化合物玻璃化温度和清亮点呈下降趋势. 随着胆甾烯基数目减少, 化合物的玻璃化温度和清亮点降低.  相似文献   

15.
丁涪江  赵可清 《化学学报》2007,65(15):1454-1458
我们最近的实验显示: 对于分子中含有酰胺基的苯并菲液晶化合物C18H6(OC5H11)3(OCH2CONHC4H9)3, 对称化合物有比反对称异构体更高的清亮点和更有序的六方柱状介晶相, 且与具有同样软链长度的分子中不含酰胺基的化合物C18H6(OC5H11)3(OCH2COOC4H9)3相比较, 有更高的清亮点和更丰富的柱状介晶相. 本文通过量子化学ONIOM (B3LYP/6-31G(d,p):UFF)计算, 说明对于带酰胺基的分子, 对称分子比反对称分子有较大的稳定化能和较高的转动势垒. 对于对称性分子, 带酰胺基的分子比带酯基的分子有较大的稳定化能和较高的转动势垒. 这说明由酰胺基形成的分子间氢键起了稳定液晶相和锚定六方柱状相的作用, 可以解释带酰胺基的分子和对称性分子有较高的清亮点和更有序的六方柱状介晶相. 如果加长酰胺基的软链, 则可使氢键锚定的扭转角减少, 这样有利于提高电荷传输速率.  相似文献   

16.
Symmetrical and asymmetrical triphenylene discotic liquid crystals with two kinds of different peripheral chains, sym-TP(OC11H23)3(O2CR)3 and asym-TP(OC11H23)3(O2CR)3, (R=CH2OC2H5, CH2OC3H7, CH2OC4H9, CH2OC5H11, C3H7, C4H9, C5H11, C6H13, C7H15) were synthesized. Their thermotropic liquid crystalline properties were studied by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The results showed that the asymmetrical compounds had higher melting and clearing points than that of their corresponding symmetrical compounds. For the same series of compounds, TP(OC11H23)3(O2CR)3, their melting points decrease and clearing points increase gradually with the lengthening of ester chains. Most of the β-oxygen containing esters of triphenylene derivatives, TP (OC11H23)3(O2CR)3, (R=CH2OC2H5, CH2OC3H7, CH2OC4H9, CH2OC5H11), symmetrically or asymmetrically attached on triphenylene cores, have higher melting and clearing points than those of triphenylene derivatives, TP(OC11H23)3(O2CR)3, (R=C4H9, C5H11, C6H13, C7H15), with the same length of peripheral chains. The triphenylene derivatives with longer peripheral chains have shown mesophase at room temperature. __________ Translated from Chemical Research and Application, 2007, 19(10) (in Chinese)  相似文献   

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