Synthesis and mesomorphism of 1,3-benzenedicarboxylic acid derivatives

4-Methoxy-l,3-benzenedicarboxylic acid esters and 4-(4-hexyloxybenzoylamino)phenyl 1,3-benzenedicarboxylate, each containing five aromatic rings, were synthesized. The influence of the structure of the synthesized banana-like compounds on their mesogenic activity was examined.     

Synthesis of ferrocene derivatives exhibiting low-temperature mesomorphism

Novel ferrocenomesogens exhibiting low-temperature mesomorphism have been synthesised from 4-ferrocenylphenol and n-alkoxy naphthoic acid intermediates (n = 4 to 16). The phase behaviour has been investigated in detail by polarising optical microscopy and differential scanning calorimetry.     

Discotic liquid crystals of transition metal complexes: 22. synthesis and mesomorphism of octa-alkoxy-substituted tetraphenylporphyrin derivatives and their copper(II) complexes

Ten novel long-chain-substituted porphyrin derivatives, tetrakis (3,4-dialkoxyphenyl)porphyrins [abbreviated as (CnO8)TPPM: M=H2, n=4, 6, 8, 10, 12, 16, 18; M=Cu, n=8, 12 and (2EtC6O)8TPPH2], were synthesized and their mesomorphism was investigated. Among them four derivatives, (CnO)8TPPH2(n=12, 16, 18) and (C12O)8TPPCu, exhibited a monotropic discotic lamellar (DL) mesophase.     

Molecular parameters and mesomorphism of discotic polysubstituted benzene derivatives

The previously developed approach to prediction of columnar and nematic mesophases for compounds with disc-shaped molecules was applied to low-molecular-weight polysubstituted benzene derivatives. The molecular parameters were calculated for 39 new compounds: derivatives of 1,3,5-tri(4-hydroxybenzoyloxy)benzene, 1,3,5-tri(4-cyclohexylbenzoyloxy)benzene, 1,3,5-tri(4-hydroxyphenylcarboxy)benzene, 1,2,3-tri(4-cyclohexylbenzoyloxy)benzene, etc. The prediction results were checked by the synthesis of certain compounds from the test sample and examination of their mesomorphic behavior. The prediction of the mesomorphism is negative for only three of the 39 compounds considered. The majority of the molecules under consideration tend to form columnar supramolecular packings, and the capability to form a nematic phase is predicted for only eight compounds. For a number of structures, the capability and incapability to form a nematic phase are equally probable. Synthesis and examination of the mesomorphic behavior of seven repesentatives of the series considered showed good agreement with the prediction results. 1,3,5-Tri(4-heptyloxybenzoyloxy)benzene, 1,3,5-tri(4-cyclohexylbenzoyloxy)benzene, 1,3,5-tri(4-nonyloxyphenylcarboxy)-benzene, and 1,2,3-tri(4-cyclohexylbenzoyloxy)benzene pass into the liquid crystal state forming mainly columnar supramolecular packings. 1,3,5-Tri(4-octyloxybenzoyloxy)benzene and 1,3,5-tri(4-nonyloxybenzoyloxy)benzene melt at 55 and 48°C, respectively, without forming a mesophase, which is also well consistent with the prediction results.     

Synthesis and investigation of triphenylene discotic derivatives with donor and acceptor groups and with predictable type of mesomorphism

Prognosis of columnar mesomorphism is performed, five new hexa-and hepta-substituted triphenylene derivatives with donor and acceptor groups are synthesized and their mesomorphoc properties are stusied. Good agreement is achieved between predictions and experiments. The synthesized triphenylene derivatives are found to display enantiotropic columnar mesomorphism. 1-Amino-2,3,6,7,10,11-hexaheptyl-xytriphenylene anilides of 2,3,5-triiodo-, 3,4,5-trihydroxy-and 4-nitro-benzoic acids reveal enantiotropic dimesomorphism. Also found decrease in thermal stability and extension of the interval of existence of mesophase at introduction to triphenylene frame of substituents with acceptor groups at the amino group.     

四苯基卟啉及其衍生物的合成

对四苯基卟啉及其衍生物的合成进行了大量研究，探讨了近三十种常用的有机溶剂中，选用三十五种常用的有机酸、无机酸催化吡咯和苯甲醛缩合。结果发现：吡咯与相应的取代苯甲醛在回流状态下缩合得到目标化合物。     

Electrochemical properties of derivatives of tetraphenylporphyrin in dichloromethane

The method of cyclic voltammetry was used to study electrochemical properties of derivatives of tetraphenylporphyrin in dichloromethane. In the case of substituted tetraphenylporphyrin, as dependent on the nature of substituents at the periphery of the porphyrin ring, reduction of porphyrins occurs in the range of negative potentials resulting in formation of a π-anion-radical and dianion, while oxidation of porphyrins with formation of a π-cation-radical and dication occurs in the range of positive potentials. In the case of tetrakis(p-aminophenyl)porphyrin, a poly-porphyrin film is formed on the electrode in the course of electrooxidation. The method of chronoamperometry was used to determine the potential of initiation of electropolymerization of H₂T(p-NH₂Ph)P.     

Synthesis and mesomorphism of tetrafluoro substituted 4-cyano oligophenyls

ABSTRACT

The synthesis and characterisation of new liquid crystal (LC) compounds based on terphenyl core are described. New family of dielectrically positive compounds presents alternative molecular approach to the conventional LC design. Correlations between molecular structure and mesomorphic properties for compounds being cyano terminated analogues as well as other known from the literature have been drawn. Compounds are characterised by ¹H NMR spectroscopy and mass spectrometry (electron ionisation) analysis. They show monotropic nematic behaviour in broad temperature range, confirmed by a polarising thermomicroscopy, differential scanning calorimetry. Detailed synthetic procedures are attached. Synthesised compounds stand as promising components of medium to highly birefringent liquid crystalline mixtures.     

Synthesis and mesomorphism of ionic self-assembled complexes of anthraquinones

Anthraquinones are known to exhibit mesomorphism upon appropriate substitutions. In this report, the concept of ionic self-assembly has been applied to design and synthesise new anthraquinone-based liquid crystals. Four different anthraquinones were used as polyelectrolytes which form ionic complexes with double-tail ammonium surfactants. The chemical structures were characterised by spectral techniques and elemental analysis. The thermal behaviour of the complexes was investigated by polarising optical microscopy, differential scanning calorimetry, thermogravimetric analysis and X-ray diffraction studies. All these complexes display lamellar mesomorphism. The amphotropic nature of the complexes has also been studied.     

Synthesis and photophysical properties of N-fused tetraphenylporphyrin derivatives: near-infrared organic dye of [18]annulenic compounds

A variety of N-fused porphyrin derivatives were prepared and their photophysical properties were investigated. Although intact N-fused tetraarylporphyrins showed almost no emission, introduction of electron-withdrawing groups such as a nitro group and a cyano group on the macrocycles caused significant refinements in their emission efficiency. Long emission wavelengths (900-1000 nm) as well as fairly large Stokes shifts (～1200 cm(-1)) are exceptionally unique photophysical properties among [18]annulenic compounds, which could be rationalized by the excited state intramolecular proton transfer (ESIPT) process. Relatively weak emission quantum yields (～5.0 × 10(-4)) and unusually short S(1) state lifetimes (～13.5 ps) are in good agreement with the ESIPT process. The solvent and substituent effects on the photophysical properties are also discussed in conjunction with the theoretical studies, where the mesityl groups at the meso-positions play a unique role.     

Synthesis and mesomorphism of 4,4'-bis(omega-hydroxyalkoxy)-alpha-methylstilbenes

A homologous series of 4,4'-bis(omega-hydroxyalkoxy)-alpha-methylstilbenes, denoted HAMS-n, has been synthesized. Here n is the carbon atom length of the peripheral n-alkyl chain; in this work n = 2 to 8 and 11. The composition, microstructure, thermal properties, and mesomorphism of the homologues were determined using elemental analysis, ¹H NMR, FTIR, DSC, wide angle X-ray diffraction, and polarizing optical microscopy with a heating stage. The influence of the length and the even/odd numbers of methylene units of the peripheral chains on the variants of mesomorphism and the stability of mesophases, as well as on their transition temperatures, are discussed. The homologues with n = 8 and 11 were enantiotropic monomorphic, CrG (or CrH). The odd homologues showed monotropic trimorphism on cooling, while the even homologues exhibited enantiotropic trimorphism. A pronounced even/odd effect on the melting temperatures was observed.     

Synthesis and mesomorphism of diacetylene-bridged triphenylene discotic liquid crystal dimers

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...     

Synthesis and mesomorphism of 4,4'-bis(omega-hydroxyalkoxy)-alpha-methylstilbenes

A homologous series of 4,4'-bis(omega-hydroxyalkoxy)-alpha-methylstilbenes, denoted HAMS-n, has been synthesized. Here n is the carbon atom length of the peripheral n-alkyl chain; in this work n = 2 to 8 and 11. The composition, microstructure, thermal properties, and mesomorphism of the homologues were determined using elemental analysis, ¹H NMR, FTIR, DSC, wide angle X-ray diffraction, and polarizing optical microscopy with a heating stage. The influence of the length and the even/odd numbers of methylene units of the peripheral chains on the variants of mesomorphism and the stability of mesophases, as well as on their transition temperatures, are discussed. The homologues with n = 8 and 11 were enantiotropic monomorphic, CrG (or CrH). The odd homologues showed monotropic trimorphism on cooling, while the even homologues exhibited enantiotropic trimorphism. A pronounced even/odd effect on the melting temperatures was observed.     

含西佛碱的3,6-双取代哒嗪的合成和介晶性

合成了8个中心桥连基为哒嗪环、酯基、CH=N基,含有胆甾基、三个苯环、不同未端链长度的双取代哒嗪化合物,并通过示差扫描量热法（DSC）对其介晶性进行了表征。研究表明,末端链长度对相变温度和清亮点温度均有影响,但对相变温度范围影响小。     

Synthesis and mesomorphism of new aliphatic polycarbonates containing side cholesteryl groups

New cholesterol side-functionalised polycarbonate polymers were synthesised by the ring-opening homo- and copolymerisation reaction of the cyclic monomer cholesteryl 5-methyl-2-oxo-1,3-dioxane-5-carboxylate and d,l-lactide using Sn(Oct)₂ as a catalyst. The chemical structures and average molecular weights of the cyclic monomer, homopolymer and block copolymers obtained in this study were characterised using FT-IR, ¹H NMR and gel permeation chromatographic measurement. The mesomorphism and mesophase structure were investigated with polarising optical microscopy, differential scanning calorimetry and X-ray diffraction measurement. As a result, the homopolymer and block copolymers showed an enantiotropic smectic A (SmA) phase. With the concentration of the lactide segment increasing, the glass transition temperature and isotropic temperature of the corresponding block copolymer all decreased. In addition, XRD suggested that the homopolymer and two block copolymers showed the SmA double-layer packing of side chains.     

用光度法测定四苯基卟啉及其衍生物的表观质子化常数

本文用光度法测得九种不同卟啉化合物的质子化常数, 并用HMO和MNDO方法计算了有关分子和分子单元, 理论分析解释了实验结果。     

Synthesis and properties of rhenium tricarbonyl complex bearing N-fused tetraphenylporphyrin ligand

An N-fused porphyrin rhenium complex was synthesized by the thermal reaction of an N-confused porphyrin with Re2(CO)10 and its structure was determined by X-ray crystallographic analysis.