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1.
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   

2.
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   

3.
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   

4.
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.  相似文献   

5.
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   

6.
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   

7.
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) (6a~6f), 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, 6a~6e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   

8.
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   

9.
Truxene discotic liquid crystals are interesting for their polymesomorphism and as organic semiconductor candidates. We developed an efficient synthetic method for C3-symmetrical truxene derivative 2,7,12-trihydroxy-3,8,13-trimethoxytruxene 5, and further a series of ether–ester mixed tail truxene discogens HTn, TR(OMe)3[OOCC6H2(OCnH2n+1)3]3 were prepared. The truxene discogens HTn (n?=?4–8, 10, 12) were characterised by using 1H and 13C nuclear magnetic resonance, and high-resolution mass spectrometry. Their thermal stability was studied with thermal gravimetric analysis and their liquid crystal properties were investigated by using polarising optical microscopy, differential scanning calorimetry and X-ray diffraction. They exhibit a hexagonal columnar (Colh) mesophase in fairly wide temperature ranges.  相似文献   

10.
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   

11.
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   

12.
赵可清  高彩艳  胡平  汪必琴  李权 《化学学报》2006,64(10):1051-1062
合成了三个系列, 共二十四个有两种不同软链的对称和非对称苯并菲盘状液晶化合物, C18H6(OR)3- (OCH2COOEt)3, C18H6(OR)3(OCH2COOBu)3, C18H6(OR)3(OCH2CONHBu)3, 其中R=C5H11, C6H13, C7H15, C8H17. 化合物通过柱层析纯化, 结构通过1H NMR, IR, 元素分析等确证. 化合物热稳定性通过TGA测定, 并显示出较高的热稳定性. 通过偏光显微镜和差视扫描量热法对这些化合物的热致液晶性进行了研究. 结果显示: 对于苯并菲液晶化合物C18H6(OR)3(OCH2COOEt)3, 非对称性化合物较之对称异构体化合物有更低的熔点和更高的清亮点, 因而非对称性化合物有更宽的介晶温度范围. 对于分子中含有酰胺基的苯并菲液晶化合物C18H6(OR)3(OCH2CONHBu)3, 对称化合物有比非对称异构体更高的清亮点和更有序的六方柱状介晶相, 且其与具有同样软链长度的分子中不含酰胺基的化合物系列C18H6(OR)3(OCH2COOBu)3相比较, 由于柱内分子间氢键的形成, 不仅有更高的熔点和清亮点, 而且有更丰富的柱状介晶相.  相似文献   

13.
Two novel bimetallic complexes, [Cr(CO)3(η 6-C6H5)–C≡C–C6H4–Fc] (Fc = C5H5FeC5H4] (1) and [Cr(CO)3(η 6-C6H5)–C ≡ C–Fc–C(CH3)2–Fc] (3), were synthesized by the Sonogashira coupling reaction. By using of (1) and (3) as ligands to react with Co2(CO)8, two others novel polymetallic complexes, [Cr(CO)3(η 6-C6H5){Co2(CO)6-η 2-μ 2-C≡C–}–C6H4–Fc] (2) and [Cr(CO)3(η 6-C6H5){Co2(CO)6-η 2-μ 2-C≡C–}Fc–C(CH3)2–Fc] (4) were obtained. Four carbonyl complexes were characterized by elemental analysis, FT-IR, NMR and MS. The molecular structures of complexes (1), (2) and (4) were determined by single crystal X-ray diffraction. The interactions among the ferrocenyl, Cr(CO)3 and Co2(CO)6-η 2-μ 2-C≡C– units were investigated by cyclic voltammetry.  相似文献   

14.
For the first time the interactions between zinc(II)tetra-4-alkoxybenzoyloxiphthalocyanine (Zn(4—O—CO—C6H4—OC11H23)Pc) and 1,4-diazabicyclo[2.2.2]octane (DABCO) in o-xylene and chloroform have been studied by calorimetric titration and NMR and electron absorption spectroscopic methods. It has been found that in o-xylene at concentrations of Zn(4—O—CO—C6H4—OC11H23)Pc higher than 6×10−4 mol⋅L−1 ππ dimers species are formed (λ max= 685 nm). Additions of DABCO to the solution up to mole ratio 1 : 8 (Zn(4—O—CO—C6H4—OC11H23)Pc : DABCO) lead to a shift of the aggregation equilibrium towards monomer species due to formation of monoligand axial complexes. Further increasing the DABCO concentration results in formation of Zn(4—O—CO—C6H4—OC11H23)Pc—DABCO—Zn(4—O—CO—C6H4—OC11H23)Pc sandwich dimers (λ max= 675 nm).  相似文献   

15.
Abstract  Formal [2 + 2 + 2] addition reaction of [Cp*Ru(H2O)(NBD)][BF4] (NBD = norbornadiene) with 4,4′-Diethynylbiphenyl generates [C9H96-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2. The reaction of [Cp*Ru(H2O)(NBD)][BF4] with 1,4-diphenylbutadiyne generates the unusual [2 + 2 + 2] additional organic compound Ph–C≡C–C9H8–Ph in addition to the organometallic compound [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4]. [C9H96-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BPh4]2 is generated after the reaction of compound [C9H96-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2 with Na[BPh4]. The structure of this compound was confirmed by X-ray diffraction. A possible approach to form Ph–C≡C–C9H8–Ph and [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4] is suggested. Graphical Abstract  Formal [2 + 2 + 2] addition reaction of [Cp*Ru(H2O)(NBD)]BF4 (NBD = norbornadiene) with 4,4′-Diethynylbiphenyl generates [C9H96-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2. The reaction of [Cp*Ru(H2O)(NBD)][BF4] with 1,4-diphenylbutadiyne simply generates unusual [2 + 2 + 2] additional organic compound Ph–C≡C–C9H8–Ph in addition to the organometallic compound [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4]. [C9H96-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BPh4]2 is generated after the reaction of compound [C9H96-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2 with Na[BPh4]. The structure of this compound was confirmed by X-ray diffraction. And the possible approach to form Ph–C≡C–C9H8–Ph and [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4] was suggested. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

16.
The gold complexes Au(C≡CC6H4C≡CC6H4Me)(PPh3) (3) and {Au(PPh3)}2(μ-C≡CC6H4C≡CC6H4C≡CC6H4C≡C) (6), prepared from the reaction of AuCl(PPh3) with the corresponding terminal or trimethylsilyl protected alkynes, react readily with Ru3(CO)10(μ-dppm) to afford phenylene ethynylene derivatives featuring the Ru3(μ-AuPPh3)(μ-C2R)(CO)7 cluster “end-caps”. The hydrido cluster Ru3(μ-H)(μ-C2C6H4C≡CC6H4Me)(CO)7 (4a) has also been obtained. There are significant differences in the absorption spectra of the organic precursors, the gold complexes and the clusters indicate a mixing of electronic states between the cluster and phenylene ethynylene moieties, while the presence of the Ru3 and in particular Ru3(μ-AuPPh3) cluster end-caps leads to a quenching of the phenylene ethynylene centred emission. The crystallographically determined structures of 3, 4a and Ru3(μ-AuPPh3) (μ-C2C6H4C≡CC6H4Me)(CO)7 (4b) are reported.Dedicated to Professor B.F.G. Johnson, one of the pioneers of cluster chemistry, in recognition of his outstanding contributions to the field.  相似文献   

17.
The synthesis and mesomorphic properties of novel non-symmetrical discotic dimers have been investigated. Dimers have been prepared by the combination of electron-deficient (n-type) anthraquinone and electron-rich (p-type) triphenylene discotic monomers. The mesophases have been characterised using polarising optical microscopy, differential scanning calorimetry and X-ray diffraction. Most of the dimers have been shown to exhibit a rectangular columnar mesophase and one has a nematic columnar mesophase also. Charge transfer behaviour has been studied by UV–Vis spectroscopy.  相似文献   

18.
Several new gold-containing cluster complexes have been prepared from the reactions of gold alkynyl complexes, L n M-C x -Au(PPh3), (x = 3, 4, 6) with Ru3(CO)10(NCMe)2. The bis-cluster complex 1,4-{AuRu3(CO)9(PPh3)(μ3-C2)}2C6H4 was obtained from Ru3(CO)10(NCMe)2 and 1,4-{(Ph3P)Au(C≡C)}2C6H4. The complexes Ru3(μ-H){μ3-C2C≡C[Ru(PP)Cp′]}(CO)9 [PP = (PPh3)2, Cp′ = Cp; PP = dppe, Cp′ = Cp*] were also obtained as minor by-products and synthesised independently from Ru(C≡CC≡CH)(PP)Cp′. A reaction between Co33-CC≡CC≡CAu(PPh3)}(μ-dppm)(CO)7 and Ru3(CO)12 afforded {(Ph3P)(OC)9AuRu3}C≡CC≡CC{Co3(μ-dppm)(CO)7} 7. Related complexes AuRu33-C2C≡[M(CO)2Tp]}(CO)9(PPh3) (M = Mo 8, W 9) were obtained from {Tp(OC)2M}≡CC≡C{Au(PPh3)}, while the mixed metal cluster complexes MoM2(C2Me)(CO)8Tp (M = Ru 13, Fe 14) were obtained from M(≡CC≡CSiMe3)(CO)2Tp (M = Mo, W) with Fe2(CO)9 and Ru3(CO)12, respectively. Reactions of the Mo carbyne complex with Co2(LL)(CO)6 [LL = (CO)2, μ-dppm] or nickelocene afforded complexes 15–17 in which Co2 and Ni2 fragments, respectively, had coordinated to the C≡C triple bond. XRD structural determinations of 7, 8, 14, 16 and {Tp(OC)2W}≡CC≡CC≡{Co3(μ-dppm)(CO)7} (18-W) are reported. In memoriam: F. Albert Cotton (1930–2007).  相似文献   

19.
The reactions of salts of the anion [2-B10H9(N≡CMe)] with aliphatic alcohols ROH (R = C n H2n+1 (n = 1–6) CH2CH2(OEt), Pri, Bui, But, i-C5H11) are studied. These reactions result in hydrolytically stable imidates [2-B10H9{NH=C(OR)Me}]. Their structures were confirmed by the data from mass spectrometry, IR, 1H, 11B, and 13C NMR spectroscopy. The molecular geometry of [2(Z)-B10H9{NH=C(OBu)Me}], which formed in nucleophilic addition reaction of n-butyl alcohol to [2-B10H9(N≡CMe)], was established by X-ray diffraction analysis.  相似文献   

20.
New dicatenar isoquinoline‐functionalized pyrazoles, [HpzR(n,n)iq] (R(n,n)=C6H3(OCnH2n+1)2; n=4, 6, 8, 10, 12, 14, 16, 18), have been strategically designed and synthesized to induce mesomorphic and luminescence properties into the corresponding bis(isoquinolinylpyrazolate)platinum(II) complexes [Pt(pzR(n,n)iq)2]. Thermal studies reveal that all platinum(II) compounds exhibit columnar mesophases over an exceptionally wide temperature range, above 300 °C in most cases. The photophysical behavior was also investigated in solution and in the solid state. As a consequence of the formation of Pt???Pt interactions, the weak greenish emission of the platinum derivatives turns bright orange in the mesophase. Additionally, the complexes are sensitive to a great variety of external inputs, such as temperature, mechanical grinding, pressure, solvents, and vapors. On this basis, they are used as dopant agents of a polyvinylpyrrolidone or poly(methyl methacrylate) polymer matrix to achieve stimuli‐responsive thin films.  相似文献   

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