Preparation and Application of Cholesteryl‐Benzo‐15‐Crown‐5/Cholesteryl Mixed Liquid Crystals

Various mixed liquid crystals containing crown ether‐cholesteryl liquid crystal, benzo‐15‐crown‐5‐COO‐C₂₇H₄₅ (B15C5‐COOCh), with various common cholesteric liquid crystals, e.g., cholesteryl chloride, cholesteryl benzoate and cholesteryl palmitate, were prepared and studied using polarizing microscopy and differential scanning calorimetry. Investigating the concentration effect of B15C5‐COOCh in mixed liquid crystals revealed that the addition of B15C5‐COOCh resulted in wider phase transition temperature ranges of these cholesteryl liquid crystals. The stability of these B15C5‐COOCh/cholesteryl mixed liquid crystals was studied using comprehensive graphic molecular modeling computer programs (Insight II and Discover) to calculate their molecular energy and stability energy. The effect of salts, e.g. Na⁺, Co³⁺, Y³⁺ and La³⁺, on the transition temperature range of the mixed liquid crystals was also investigated. The crown ether cholesteric liquid crystal B15C5‐COOCh was applied both as a surfactant and an ion transport carrier to transport metal ions through liquid membranes. Cholesteryl benzo‐15‐crown‐5 exhibited distinctive characteristics of a surfactant and the critical micellar concentration (CMC) of the surfactant was investigated by the pyrene fluorescence probe method. Cholesteryl benzo‐15‐crown‐5 was successfully applied as a good ion transport carrier (Ionophore) to transport various metal ions, e.g. Li⁺, Na⁺, La³⁺, Fe³⁺ and Co³⁺, through organic liquid membranes. The transport ability of the cholesteryl benzo‐15‐crown‐5 surfactant for these metal ions was in the order: Co³⁺ ≥ Li⁺ > Fe³⁺ > Na⁺ > La³⁺.     

New Tolan‐type Liquid Crystals with 1, 3‐Dithiane Ring

Two new tolan‐type liquid crystalline (LC) materials, 2‐[4‐(4‐pentoxyphenyl)ethynylphenyl]‐5‐pentyl‐l,3‐dithiane (A) and 2‐[4‐(4‐pentoxy‐2, 3, 5, 6‐tetrafluorophenyl) ethynylphenyl]‐5‐pentyl‐1, 3‐dithiane (B) were synthesized and their mesomorphic behavior was determined. The 1, 3‐dithiane‐type compound A exhibits only nematic phase. The compound B, fluorosubstituted in the LC core, shows the same nematic phase range.     

Macrocyclic Polyether Phase Transfer Catalysts for Free Radical Polymerization of Acrolein

Macrocyclic polyethers, e.g., crown ethers and cryptands, were prepared and employed as phase transfer catalysts for free radical polymerization of acrolein, a vinyl monomer, with persulfates (S₂O₈^2–) as initiators. The catalytic abilities of various macrocyclic polyethers as catalysts for the free radical polymerization of acrolein were found to be in the order: benzo‐15‐crown‐5 > dibenzo‐18‐crown‐6 > 12‐crown‐4 > 15‐crown‐5 > 18‐crown‐6 > cryptand‐22 with sodium persulfate (Na₂S₂O₈) as initiator. Sodium persulfate proved to be a better initiator than ammonium persulfate or potassium persulfate with benzo‐15‐crown‐5 as a catalyst. Effects of solvents and temperature on the catalytic polymerization were also investigated. The polymerization rates in various solvents were in the order: dioxane > benzene > acetonitrile > acetone > dichloromethane > hexane > water. Comparison between bulk polymerization and solution polymerization was also made. Higher polymerization rate was observed at higher temperature. The molecular weights of polyacrolein and the conversion of monomer in reaction period were determined with gel permeation chromatography and ultra‐violet spectrophotometry, respectively. Concentration effects of crown ether and initiator were also investigated and discussed.     

Macrocyclic amidophosphoryl polyethers: Biological activity,molecular structure,and structure of the complex with calcium thiocyanate

The antihypoxic and anticonvulsant activity of eight new amidophosphoryl derivatives of crown ethers was investigated. It was found that some of them exhibit pronounced antihypoxic activity. The results of an x-ray structural and IR spectroscopic study of dibenzo-N-phenylphosphonyl-14-crown-5 (a=9.818,b=16.062,c=15.925 Å; =124.90°;V=2072 ų;M=417.2;d=1.33 g/cm³ forZ=4, 1955 independent reflections [I>3(I)] in a DAR-UM inCuK radiation,P2 ₁/b space group,R=5.2%) and dibenzo-N-adamantylphosphonyl-14-crown-5 compounds (a=11.077,b=15.936,c=16.771 Å; =56.05°;V=2456 ų;M=486.3;d=1.31 g/cm³ forZ=4, 2164 independent reflections [I>3(I)] in a DAR-UM inCuK radiation,P2₁/b space group,R=5.1%) are reported. Some details of the structure of the dibenzo-N-phenylphosphonyl-14-crown-5-complex with calcium thiocyanate and water are discussed; a polyhedron with a coordination number of six was found for the first time for calcium complexes with macrocyclic ligands. The combined examination of the results of the biological, x-ray structural, and IR spectroscopic study of macrocyclic, 14-member ligands suggested that the nature of the substituents at phosphorus affect the conformational state of the macrocycle, which remains unchanged in complexation in the investigated conditions.Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences, 142432 Chernogolovka. Institute of Physiologically Active Substances, Russian Academy of Sciences, 142432 Chernogolovka. Institute of Organic Chemistry, Ukrainian Academy of Sciences, 252660 Kiev. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 12, pp. 2784–2790, December, 1992.     

Synthesis of poly(2‐furyloxirane) with high molecular weight and improved regioregularity using macrocyclic ether as a cocatalyst to potassium tert‐butoxide

2‐Furyloxirane (FO), a monomer usually obtained from a nonpetroleum route, was prepared from the epoxidation reaction of furfural and trimethylsulfonium chloride. About 200–300 g FO can be obtained in each preparation process. Although anionic polymerization of FO generally gives low‐ molecular‐weight polymers even after long periods of polymerization, the reaction was greatly improved when macrocyclic ether was used as a cocatalyst to potassium tert‐butoxide. When 18‐crown‐6 was used as a cocatalyst, poly(2‐furyloxirane) (PFO) with a number‐average molecular weight (M_n) of 41.5 kg/mol and a polydispersity index of 1.3 was obtained at 94% yield after polymerization at 40 °C for 72 h. The PFO obtained contained a 61.7% head‐to‐tail (H‐T) structure in the absence of the macrocyclic ether, and it reached 70.6% when cryptand[2,2,2] was used as a cocatalyst. PFO with higher regioregular structures showed improved thermal properties. For PFO with M_n of around 20.0 kg/mol, its glass transition temperature (T_g) increased from ?3 to 6 °C when the H‐T content was increased from 61.7 to 70.6%. Raising the M_n of PFO also raised T_g. For PFO with 68.9% H‐T structure, its T_g could reach 7 °C when M_n was increased to 40 kg/mol. This study shows two effective ways to improve the thermal and mechanical performances of the polymer. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

两个新的氢键诱导液晶化合物的合成

通过４－丁氧基苯甲酸（４ＢＡ０与两个手性取代的苯乙烯基吡啶（ＶＳＺ及ＬＳＺ）间的氢键作用合成了２个新的液晶化合物，用ＤＳＣ、偏光显微镜研究了其液晶行为，并由红外光谱证实了分子间氢键的存在，形成的复合物４ＢＡ－ＶＳＺ具有手性近晶Ｃ相。     

Potentiometric Determination of Non‐Ionic Surfactants by Liquid Membrane Electrodes

It is well known that non‐ionic surfactants (NIS) influence remarkably the potentiometric measurements with liquid membrane ion selective electrodes (ISEs), interfering particularly on performance of ISEs for earth‐alkali metals, for which the loss of selectivity with regard to alkali metals has been documented. These studies indicate that such interferences are due to the extraction of surfactants within the membrane, where a competition takes place between the originally present ionophore and the surfactant which also acts as a ligand for alkali metals. The interpretation of such phenomena enabled one to exploit this interference for analytical purposes by membrane/solution extraction experiment monitored by UV measurements and by impedance FRA analysis on coated wire electrodes. Using Ca/Mg ISEs based on the neutral ionophore ETH 4030, it has been established that the logarithm of the Ca/Mg over Na potentiometric selectivity constant is linearly correlated with the concentration of NIS like Tegopren 5863 and Triton X‐100. The proposed method has been applied for the development of a new potentiometric analytical procedure for the determination of Tegopren 5863 in synthetic seawater (SSW), ranging from 0.25 to 5 ppm. Our procedure consists in the exposure of the electrode to stirred SSW containing the surfactant; the progressive extraction of Tegopren 5863 causes a growth in electrode's sensitivity to Na⁺ and K⁺, losing selectivity for Ca²⁺ and Mg²⁺. In turn this induces an increase of EMF, as all these ions are present in the studied matrix. The potential drift was monitored for 15 hours, showing that the process reaches thermodynamic equilibrium after about 12 hours of exposure. This method presents a value of 210 ppb of Tegopren 5863 as detection limit.     

Syntheses and Crystal Structures of Two New Macrocyclic Compounds

Two new macrocyclic compounds, [Cu2(L)2](ClO4)4·2CH3OH (1) and [Cu(L)](ClO4)2·2H2O (2) (L = 1,3,10,12,15,18-hexaazatetracyclodocosane) were synthesized by condensation reactions involving amines and formaldehyde in the presence of copper anion. Compound 1 crystallizes in triclinic, space group Pí with a = 10.442(2), b = 14.197(3), c = 17.388(4), α = 91.218(4), β = 90.69(3), γ = 93.756(4)o, V = 2520.4(9)3, Z = 2, F(000) = 1260, Dc = 1.589 Mg/m3, Mr = 1205.92, μ = 1.137 mm-1, λ = 0.71073, the final R = 0.0668 and wR = 0.1573 for 9703 observed reflections with I > 2σ(I). Compound 2 crystallizes in monoclinic, space group C2/c with a = 16.911(2), b = 11.4172(15), c = 27.059(4), β = 107.787(2)o, V = 4974.7(12)3, Z = 8, F(000) = 2504, Dc = 1.610 Mg/m3, Mr = 602.92, μ = 1.155 mm-1, λ = 0.71073 , the final R = 0.0419 and wR = 0.1131 for 4374 observed reflections with I > 2σ(I).     

二苯乙炔类液晶的合成

以碘代烷基苯（或联苯）与烷基苯乙炔为中间体，采用二价镍为催化剂的方法合成了二苯乙炔类液晶化合物。其相变过程通过差热分析测试，该类化合物表现出优良的液晶性能。     

Some Peculiarities of the Radical Polymerization of Methyl Methacrylate in the Presence of Low Molecular Weight Liquid Crystals

Abstract

Radical polymerization of methyl methacrylate (MMA) in the presence of propylbenzene, benzonitrile, their equimolar mixture, and a mixture of nematic liquid crystals (LC) was studied. Chain transfer reaction and unexpected dependence of the initial polymerization rate on LC concentration were revealed by means of UV spectrophotometry, viscometry, and dilatometry. The chain transfer reaction which occurred at the boundary of LC domains in the polymer matrix caused binding of some of the LC molecules to the macromolecules of PMMA. An increase in the initial rate of polymerization and a decrease of polydispersity were explained with formation of the LC phase because growth of the macroradicals continued not only in the homogeneous polymer phase but simultaneously also at the interfacial boundary between the polymer matrix and the LC phase. It is assumed that the LC molecules anchored to the PMMA matrix can affect the mobility of free LC molecules in the LC domains when an external electric field is applied to LC/polymer composite films.     

新型大环Schiff 碱化合物的合成及其晶体结构

以间苯二酚和二乙烯三胺为原料, 经缩合成环作用得到一新型Schiff 碱大环化合物1. 单晶X射线衍射结果表明, 该化合物属于单斜晶系, P21/c空间群, 晶胞参数为a＝0.81977(9) nm, b＝1.27817(14) nm, c＝1.60193(17) nm, α＝90°, β＝93.34(3)°, γ＝90°, V＝1.6757(3) nm3, Z＝4, R1＝0.0553, wR2＝0.1603. 在分子的大环结构中形成了四个N＋—H…O－离子型氢键, 化合物分子呈现为一四边形结构框架, 两个相互平行的苯环间存在较强p-p相互作用.     

Catalytic Performance of Ruthenium‐Supported Ionic‐Liquid Catalysts in Sustainable Synthesis of Macrocyclic Lactones

Thirteen‐ to eighteen‐membered lactones were synthesized by ring‐closing olefin‐metathesis reactions of bis‐olefins with heterogeneous Grubbs‐supported ionic‐liquid catalysts (SILCs), in which homogeneous Grubbs catalysts were confined in pores of alumina with the aid of an ionic liquid. The Grubbs‐SILCs exhibited higher catalytic performance than their homogeneous counterparts and could be repeatedly recovered by simple filtration and re‐used several times.     

Molecular and Supramolecular Structures of a Nickel（Ⅱ） Complex with a Macrocyclic Ligand

1 INTRODUCTION The knowledge of all non-covalent interactions, such as strong and weak hydrogen bonds and p…p interactions, is important to the supramolecular chemistry, biochemistry, crystal engineering and material science[1～7]. Several mononuclear complexes of macrocyclic oxamido Schiff base ligands with phenyls have been used as 揷omplex ligands?to design polynuclear complexes[8～11]. Herein we report the molecular and crystal structures, CH贩稯 hy- drogen bonding and p…p stacki…     

Successive Chain‐Growth Condensation Polymerization for the Synthesis of Well‐Defined Diblock Copolymers of Aromatic Polyamide and Aromatic Polyether

Well‐defined diblock condensation copolymers composed of an aromatic polyamide and an aromatic polyether have been synthesized by means of successive chain‐growth condensation polymerizations. Polymerization of a polyamide monomer with an orthogonally difunctional initiator is accompanied with side reactions. On the other hand, polymerization with a monofunctional initiator afforded well‐defined polyamide, which has been converted into a macroinitiator by introduction of a terminal 4‐fluorobenzophenone unit. Well‐defined diblock copolymers are obtained by polymerization of a polyether monomer in the presence of this macroinitiator.

     

基于钒氧多酸与大环铜配合物构筑的三维配位聚合物的合成与表征

通过[CuL](ClO₄)₂(L=5,12-二甲基-1,8-二乙醇基-1,3,6,8,10,13-六氮杂环十四烷)与NH₄VO₃反应,得到一个钒氧多酸桥联大环铜配合物的三维配位聚合物{[CuL][VO₃]₂·0.67H₂O}_n。并对其进行了元素分析、红外光谱、紫外光谱、热重和X-射线单晶衍射测定。单晶结构测试结果表明配合物属于三方晶系,R3空间群。在晶体结构中,铜原子与大环配体上的四个氮原子和钒氧四面体[VO₄]中的2个氧原子配位,形成畸变的八面体构型。钒氧多酸阴离子[V₆O₁₈]^6-桥联大环配合物[CuL]²⁺形成一个具有一维通道的三维配位聚合物。     

水溶性聚合物和两亲聚合物19．磺化液体聚丁二烯──种新型液膜用表面活性剂

一种新的聚工二烯型表面活性剂ＬＹＦ经液体聚了二烯磺化方法制备而得，并应用于液膜分离研究之中。发现无论内水相是酸性还是碱性，由该表面活性剂制得的Ｗ／Ｏ型乳状液在稳定性、溶胀率和破乳诸方面均具有令人满意的综合性能。为深入了解液膜的稳定性，我们测定了处于两种水相间的双分子膜的强度。发现由ＬＹＦ所形成的双分子膜具有最大的膜强值，优于聚异丁烯型的表面活性剂ＥＣＡ４３６０和ＥＭ３０１．     

基于钒氧多酸与大环铜配合物构筑的三维配位聚合物的合成与表征(英文)

通过[CuL](ClO4)2(L=5,12-二甲基-1,8-二乙醇基-1,3,6,8,10,13-六氮杂环十四烷)与NH4VO3反应,得到一个钒氧多酸桥联大环铜配合物的三维配位聚合物{[CuL][VO3]2·0.67H2O}n。并对其进行了元素分析、红外光谱、紫外光谱、热重和X-射线单晶衍射测定。单晶结构测试结果表明配合物属于三方晶系,R3空间群。在晶体结构中,铜原子与大环配体上的4个氮原子和钒氧四面体[VO4]中的2个氧原子配位,形成畸变的八面体构型。钒氧多酸阴离子[V6O18]6-桥联大环配合物[CuL]2+形成一个具有一维通道的三维配位聚合物。     

液晶自组装多层级结构及其应用

液晶的分层组装与刺激响应特性使其在先进功能材料的开发与应用领域具有独特的优势.通过特定的技术手段诱导其自组装行为,可带来新奇的光学、机械、电磁等性能,进而实现一系列全新的技术应用.本文主要针对近晶相、胆甾相、蓝相这三种特殊的液晶相态,系统介绍了多形态焦锥畴结构,分层油纹,螺旋结构,双螺旋扭曲柱立方晶格等多层级结构,重点论述了材料组分优化,几何结构限制以及外场激励等条件下液晶多层级结构的大面积精细操控,回顾了其在粒子操控、表面改性、光子技术等领域的相关技术应用,并总结展望了液晶组装技术与应用的发展前景.     

二十四种作为麝香酮及类似大环酮重要中间体的长链二酮的仿生合成

烷基取代的大环酮（例如,名贵香料麝香酮）是珍贵的香料,天然来源稀少,它的人工合成一直是有机合成中的一个研究热点和难点。在本文中,受四氢叶酸辅酶的一碳单元转移反应的启发,作者以双苯并咪唑盐作为四氢叶酸辅酶模型,利用格利雅试剂与双苯并咪唑盐的加成-水解反应,成功合成了二十四种作为麝香酮及类似大环酮重要前体的长链二酮,同时,提供了一种麝香酮及类似大环酮的仿生合成新方法。     

Effect of Monomer Composition on the Performance of Polymer‐Stabilized Liquid Crystals with Two‐Step Photopolymerization

Polymer‐stabilized cholesteric liquid crystal (PSCLC) films with broadband reflection based on two‐step photopolymerization are fabricated. Owing to the helical twisting power (HTP) value of the chiral dopant (CD) decreasing with increasing temperature, PSCLC films with broadband reflection are obtained by two‐step polymerization anchoring helical pitch of different length at two different temperature points. The effect of monomer composition on the PSCLC reflection properties before and after polymerization was studied. The results show that the free‐radical monomers with appropriate concentration and cationic monomers with sufficient concentration are vital for the formation of PSCLC films with broadband reflection. In addition, the experiments show that the increase in the functionality and rigidity of the cationic monomer has a positive effect on the broadening of the reflection band. This study can provide guidance and reference for the selection of monomer species and concentration in PSCLC preparation. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 1126–1132