Synthesis of Diorganotin Esters of 5-Bromonicotinic Acid: X-ray Crystal Structure of Polymeric 5-Bromonicotinatodiorganotin

Two types of diorganotins [R₂Sn(OCOC₅H₃N-3-Br-5)₂] _n and {[R₂Sn(OH₂)(OCOC₅H₃N-3-Br-5)₂]₂} _n (R= Me, n-Bu, Ph, n-Oc), are prepared from 5-Br-omonicotinic acid and diorganotin oxides. All the compounds, 1–8, are characterized by elemental analysis as well as IR and ¹H-NMR spectroscopy. The crystal structures of [R₂Sn(OCOC₅H₃N-3-Br-5)₂] _n (2) and {[R₂Sn(OH₂)(OCOC₅H₃N-3-Br-5)₂]₂} _n (8) were determined by single crystal X-ray diffraction. In compound 2, each carboxylate moiety of 5-Br-omonicotinic acid is involved in coordination to one Sn atom via two O-atoms, and the N-atom of one pyridine-ring coordinates to the neighboring Sn atom which leads to a polymeric chain. And the N-atom of the other pyridine-ring is dissociative. In compound 8, the compound proves to be dinuclear macrocyclic compounds with 5-Br-omonicotinic acid bridging the adjacent tin atoms with a 12-member ring. The hydrogen bonds ( ) are observed in the compound 8. These intermolecular hydrogen bonds form another ring, and lead to a polymeric chain in the lattice at the same time. An erratum to this article can be found at     

Tin(IV) Polymers: Part 1. Synthesis of Diorganotin Esters of Thiosalicylic Acid: X-ray Crystal Structure of Polymeric Thiosalicylatodiorganotin

Thiosalicylatodiorganotin, [R₂Sn(O₂CC₆H₄S)]_n, (R=Me (1), n-Bu (2), Ph (3), 3-Cl–PhCH₂ (4)), are prepared from thiosalicylic acid and diorganotin chlorides. All the compounds, 1–4, are characterized by elemental analysis as well as IR and ¹H-NMR spectroscopy. X-ray crystallographic analysis of the 2 and 4 shows that the structures are polymeric with neighboring diorganotin centers being linked by one O-atom of the carboxylate ligands. The carboxylate moiety is involved in coordination to one Sn atom via one O-atom while the other O-atom coordinates to the neighboring Sn atom. The mercaptotropone sulfur atom is bonded to the central Sn atom thereby establishing that Sn is five-coordinate and exists in a trigonal bipyramidal geometry.     

2，5-吡啶二甲酸的合成研究

用6-甲基炯酸为原料，高锰酸钾为氧化剂，在水相的条件下合成了2,5-吡啶二甲酸。考察了氧化剂种类、原料与氧化剂配比、反应用水的量以及后处理对产品收率和纯度的影响。结果表明，用高锰酸钾为氧化剂，高锰酸钾与6-甲基烟酸的摩尔比为3；反应用水的质量为原料质量的6倍；用酸碱精制法对产品粗品进行精制，在此条件下产品的最终纯度达到99．5％以上，总收率达到70％以上。     

萘甲酸酯类液晶的合成

萘甲酸酯类液晶化合物是一种性能优越的超扭曲向列(STN)型显示材料,近年发展迅速。该文以萘为原料,经傅-克酰化、还原、氧化等反应得到重要中间体6 烷基 2 萘甲酸(nd),nd与不同取代酚反应得到10种萘甲酸酯类液晶化合物,收率4 4%～10 7%。目标化合物经过IR、1HNMR、MS结构鉴定,并考察了其相变行为特点。     

高分子固体酸催化合成乙酸甘油酯的研究

使用高磺化度的磺化聚醚砜为固体酸催化剂合成了乙酸甘油酯。考察反应物投料比、反应温度、催化剂用量等对甘油转化率和乙酸甘油酯选择性的影响。研究发现,与磺化聚苯乙烯催化剂相比,高磺化度的磺化聚醚砜催化剂具有更高的甘油转化率和二、三乙酸甘油酯选择性。并且催化剂可以重复使用多次,催化效率没有明显降低。     

甲基三乙基碳酸氢铵的合成工艺研究

甲基三乙基氢氧化铵是电子、催化等领域应用广泛的精细化工产品,可以由甲基三乙基碳酸氢铵经电解制得。以三乙胺和碳酸二甲酯为原料,采用两步法合成甲基三乙基氢氧化铵的原料甲基三乙基碳酸氢铵。从物料比、反应温度、氮气初始压力、反应时间、水解温度5个方面对合成工艺进行了优化。结果表明,在n(碳酸二甲酯)∶n(三乙胺)=1.5∶1、反应温度150℃、反应压力1.5 MPa、反应时间6 h,中间体甲基三乙基铵碳酸单甲酯的收率达90%。水解温度为70℃时,标题化合物的收率接近100%。     

Esters of N-Benzyloxyamino Acids

Methyl, t-butyl and benzyl esters of N-benzyloxyamino acids were prepared using diazomethane, t-butylacetate with perchloric acid and benzyl chloride with ethyl acetoacetate, respectively. These protected substrates may be used for the unambiguous synthesis of N-hydroxypeptides.     

利用混合二元酸制备聚酯多元醇

用工业生产尼龙 6 6副产C4～C6的混合二元酸为原料 ,在 85℃经甲醇酯化 (酯化率大于90 % )、精制 ,并在 2 0 0℃左右经乙二醇酯交换缩聚合成相对分子质量为 15 0 0～ 2 0 0 0的各种聚酯多元醇 ,用它来进一步合成聚氨酯 (PU)弹性体 ,并对其物理机械性能进行测试 ,其拉伸强度平均在 9MPa以上 ,与国外产品性能相当。所确定和优化的聚酯多元醇合成工艺在经济上是可行的     

Synthesis of Esters Under Microwave Irradiation Using Heteropoly Acids as Catalysts

A practical and simple technique for synthesis of esters was developed by using heteropoly acid as catalyst under microwave irradiation in the absence of organic solvents. Alcohols were easily and selectively converted to their acetates and benzoates with excellent yields (98%), and in very short time (5 min), as environmentally benign.     

氮杂环基取代丙氨酸及其衍生物的合成、晶体结构及荧光性能研究

采用2-(二苯亚甲氨基)乙酸甲酯和3种2-/4-溴甲基取代的含氮杂环化合物分别进行烷基化、水解反应得到了3-(1 H-苯并[d]咪唑-2-基)-2-氨基丙酸、3-(吡啶-2-基)-2-氨基丙酸及3-(噻唑-4-基)-2-氨基丙酸。所合成化合物的结构经过元素分析、¹HNMR、¹³CNMR、IR和质谱确认,并用X射线衍射法测定了化合物2-(二苯亚甲氨基)-3-(1-叔丁氧羰基-1 H-苯并[d]咪唑-2-基)丙酸甲酯及2-(二苯亚甲氨基)-3-(噻唑-4-基)丙酸甲酯晶体结构。同时测试了目标化合物及其前体化合物的荧光性质,通过测试发现上述几种化合物具有很强的荧光,增大了其作为荧光材料的应用可能性。     

Synthesis and Structure Characterization of Some Triorganotin Esters of Heteroaromatic Carboxylic Acid and Crystal Structure of Triphenyltin Esters of 6-Hydroxynicotinic Acid and 5-Chloro-6-hydroxynicotinic Acid

Reactions of (R₃Sn)₂O (R=Ph, 2-ClC₆H₄CH₂, 2-FC₆H₄CH₂, 4-CNC₆H₄CH₂) with 6-hydroxynicotinic acid and 5-chloro-6-hydroxynicotinic acid in 1:2 stoichiometry yielded eight triorganotin compounds. These compounds have been characterized by elemental analysis, IR and ¹H NMR spectroscopy. The crystal structures of triphenyltin esters of 6-hydroxynicotinic acid (1) and 5-chloro-6-hydroxynicotinic acid (2) were determined by single crystal X-ray diffraction. In these two compounds the tin atoms are rendered five-coordinate in a trigonal bipyramidal structure by coordination though the three phenyl carbon atoms and two oxygen atoms, one from carboxylate and other from the phenolic hydroxide. The resulting structures are two one-dimensional linear polymers through an interaction between the O atoms of phenolic hydroxide and tin atoms of an adjacent molecule.     

Effect of Molecular Symmetry and Intermolecular Halogen-Halogen Interactions on the Crystal Structures of Halogen-Substituted Benzoic Acids. X-ray Crystal Structure of m-Iodobenzoic Acid

The crystal structure of m-iodobenzoic acid is reported. The crystals are monoclinic, P2₁/c, with a = 6.220(3) Å, b = 4.689(2) Å, c = 26.67(1) Å, β = 101.80(3)°, Z = 4, C₇H₅IO₂. The structure has been determined by direct methods and refined to R 0.026 for 1288 reflections recorded with an automatic single crystal diffractometer. The structure is composed of essentially planar hydrogen-bonded dimer units with significant intermolecular iodine-iodine contacts. The configuration of the dimer unit is transoid. Since this is the penultimate member of the family of mono-halogen-substituted benzoic acids its structure is compared with those previously reported. In particular, the effects of differences in molecular geometry of the o-, m-, and p-isomers and the strengths of the intermolecular halogen-halogen interactions are surveyed. The geometry of the carboxyl group of m-iodobenzoic acid in the solid state and the carbonyl absorption in the Ftir spectrum of the crystalline acid at room temperature suggest the presence of dynamic proton isomerism as has been recently found by other investigators in crystalline benzoic acid and some of its derivatives.     

Synthesis of Hydrophobic Polymeric Cryogels with Supermacroporous Structure

A versatile approach to synthesis of hydrophobic polymeric cryogels is proposed using acetic acid crystals instead of ice crystals as porogen through cryo‐polymerization. In the range of 60 to 90 vol% of acetic acid, polymerization at ambient temperature gives rise to particulate polymers in beaded or amorphous shape, while polymerization at 4 °C, lower than the melting point of acetic acid (16.6 °C), leads to the formation of cryogel‐like monoliths with supermacroporous structure, which is mainly ascribed to cryo‐concentration effect. According to the measurements by scanning electron microscopy and mercury intrusion porosimetry, the dried samples are supermacroporous with pore size mainly ranging from several micrometers to several hundred micrometers, which can be feasible for rapid mass transfer. The forming cryogels display a superfast responsiveness to organic solvents, possibly stemming from their supermacroporosity and distinctive hydrophobicity.

     

2,6—萘二甲酸的合成探讨

叙述了高性能能聚合物聚萘酯（ＰＥＮ）的关键单体２,６－萘二甲酸（２,６－ＮＤＣＡ）合成的最近进展,以及采用２－甲基萘的酰化,氧经路线合成２,６－ＮＤＣＡ的概况。     

芳香二羧酸在有机溶剂中的加合结晶

加合结晶是一种新型的结晶分离方法.对三种芳香羧酸(对、邻、间苯二甲酸,TA、OPA、IPA)在6种溶剂中的结晶物质进行了分光光度法测定、热重分析和XRD表征,发现TA在6种溶剂中的结晶3种是普通结晶,3种是溶剂与溶质-同析出的加合结晶,其中又只有TA-二甲基乙酰胺(DMAC)、TA-N-甲基吡咯烷酮(NMP)两种加合结...     

结晶紫分子印迹微球的合成及其性能

以结晶紫(CV)为模板分子、α-甲基丙烯酸(MAA)为功能单体、二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,采用沉淀聚合法合成结晶紫分子印迹微球。同时,考察合成过程中不同交联剂、模板分子与MAA的配比以及交联剂用量对微球性能的影响。结果表明:采用恒温水浴振荡法,以30 mL乙腈为溶剂,模板分子、功能单体和交联剂物质的量比为1∶4∶20,所制备的聚合物微球最大吸附量Q为39.1μmol/g,分离因子(α)和印迹效率因子(β)分别为3.76和3.18,对目标分子结晶紫具有良好的特异性识别和吸附能力。     

Synthesis and Characterization of Poly(o-anisidine) Doped with Polymeric Acids

ABSTRACT

Conducting poly(o-anisidine) doped with polymeric acids [viz, poly(styrene sulphonic acid) (PSSA), poly(vinyl sulphonic acid) (PVSA) and poly(acrylic acid) (PAA)] was synthesized by in-situ chemical polymerization method using ammonium persulphate as an oxidizing agent. This is a single-step polymerization process for the direct synthesis of emeraldine salt phase of the polymer. The polymers were characterized by using UV-Vis., FT-IR spectroscopy, thermal analysis, and conductivity measurements. Formation of mixed phases of polymer together with conducting emeraldine salt phase are confirmed by spectroscopic techniques. Thermal analysis shows that PAA doped poly(o-anisidine) undergoes three stage decomposition pattern similar to unsubstituted polyaniline. While, in PSSA and PVSA, doped sample splitting up of the second weight loss stage is observed leading to a four-step decomposition pattern. Room temperature conductivity measurements show less conductivity in poly(o-anisidine) than in polyaniline, due to the cumulative steric as well as electronic effects of the bulky methoxy substituent present at ortho position on the benzene ring. Increase in conductivity with increase in temperature is observed by high temperature conductivity measurements, showing “thermally activated behavior.”     

二苯二硒的合成和晶体结构

报道了一种新的合成工艺,采用氯化镉为催化剂,利用空气中的氧气直接氧化苯硒酚合成了二苯二硒晶体,表征了其晶体结构和红外光谱性质。晶体属于正交晶系,空间群 P21 21 21,a= 0 5646 (2) nm,b= 0 8288 (3) nm,c=2 4100(9)nm; V=1 1276(7)nm3,Dc=1 839 g·cm-3,Z=4, R=0 0259。