水合三苯基锡聚合物的合成及其对PVC热稳定性的研究

在苯与甲醇体积比为3∶1的溶液中,将1,2,4-苯三酸与三苯基氢氧化锡进行脱水反应,最终获得了新型的水合三苯基锡聚合物。采用1H NMR和X-射线单晶衍射仪对其进行结构表征,结果表明,该分子是通过H2O桥联的有机锡聚合物,分子中的锡原子与2H2O配位,形成畸变的5配位三角双锥构型。初步研究结果表明,它对聚氯乙烯具有一定的热稳定性能。     

Wittig反应合成α,β-不饱和酯后处理方法的改进

本论文对Wittig反应合成α,β-不饱和酯后处理做了改进。利用副产物三苯基氧膦易结晶的特点,先用重结晶的方法除去大部分副产物三苯基氧膦后,再用柱层析色谱法纯化得到产物。该方法不但减少了硅胶和洗脱剂的用量,而且使分离效果更好,具有一定的经济和环保意义。     

三烃基锡氢化物在有机合成中的应用

简述了三烃基锡氢化物在有机合成中对 C-X 键的选择性还原、不饱和基团的加成、分子间和分子内的碳碳偶联、钯催化甲酰化、开环和扩环等反应的作用。     

化学反应-结晶法联用分离三苯基膦与三苯基氧膦

用化学反应-结晶联用法从Wittig反应废渣中回收三苯基膦和三苯基氧膦。废渣混合物经过酸处理、重结晶,分别得到三苯基膦和三苯基氧膦。考察了洗涤酸、结晶溶剂等对产品纯度和回收率的影响。结果表明,洗涤酸种类和稀酸浓度对结果无影响,重结晶溶剂选用氯苯较好,分离产物经红外、高效液相色谱和熔点分析,与文献值一致,产物纯度符合工业品要求。     

三苯基锡(Ⅳ)四氢吡咯荒酸酯的合成、表征、性质及晶体结构

用三苯基氯化锡和四氢吡咯荒酸钠反应 ,合成了三苯基锡 ( )四氢吡咯荒酸酯。通过元素分析、红外光谱和氢核磁共振谱对其结构进行了表征。用 X-射线单晶衍射测定了该化合物的晶体结构。结果表明 ,化合物中锡原子呈五配位畸变三角双锥构型     

具有生物活性的三烃基锡化合物的研究进展

主要对具有生物活性的三烃基锡化合物的研究进行回顾,其中包括不具有含硅基团的单一三烃基锡化合物、混合三烃基锡化合物,具有含硅基团的单一三烃基锡化合物、混合三烃基锡化合物,以及其它结构类型的三烃基锡化合物的生物活性研究。     

含硅氨基烃基膦酸的合成

采用芳醛、胺及亚磷酸反应的新方法,制备了五种含硅氨基烃基膦酸。用元素分析、IR、^31PNMR对合成的化合物进行了表征。     

不对称二烃基二卤化锡的合成

二烃基二卤化锡是合成其他二烃基锡化合物的重要中间体，也是重要的有机合成试剂。本文主要讨论了不对称二烃基二卤化锡的合成方法。     

丁基(乙基二甲基硅基亚甲基)锡二芳香酸酯的合成与结构表征

用丁基(乙基二甲基硅基亚甲基)氧化锡与芳香酸以1∶2的物质的量之比进行反应,合成了5个新的含硅混合二烃基锡化合物——丁基(乙基二甲基硅基亚甲基)锡二芳香酸酯。通过IR、1HNMR、13CNMR和元素分析对它们的结构进行了表征。     

阻燃剂三嗪三苯基次膦酸乙酯的合成及应用

以苯基次膦酸二乙酯和三聚氯氰为原料,合成了新型阻燃剂三嗪三苯基次膦酸乙酯,即2,4,6-三(乙氧基-苯基次膦酰基)-1,3,5-三嗪。探讨了反应时间、反应温度、苯基次膦酸二乙酯滴加速度、原料配比等对产率的影响。结果表明:三聚氯氰与苯基次膦酸二乙酯物质的量比为1:3.2、分3次滴加苯基次膦酸二乙酯、80℃下反应4 h,收率为96.3%;通过FTIR、1H-NMR、差热分析及极限氧指数等表征了产物的结构及性能。性能测试结果表明:该化合物阻燃效能高,与聚酯等高分子材料具有很好的相容性,不会降低材料的力学性能,应用开发前景广阔。     

Preparation and properties of liposomes composed of various phospholipids with different hydrophobic chains using a supercritical reverse phase evaporation method

Liposomes were prepared by the supercritical reverse phase evaporation method developed in our laboratory using various phospholipids with different hydrocarbon chains. The effects of the length of alkyl chain and number of unsaturated bonds of phospholipids on the properties of liposomal membranes were examined through trapping efficiency measurements, transmission electron microscopic observations, and osmotic response measurements. The trapping efficiency for water-soluble drugs of liposomes prepared by our method was greatly higher than that of liposomes prepared by the conventional Bangham method. Liposomes prepared using unsaturated phospholipids showed a high trapping efficiency compared with those prepared using saturated phospholipids. In addition, the trapping efficiency of liposomes prepared using 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC), a complex phospholipid with both saturated and unsaturated alkyl groups, had a value intermediate between L-alpha-dipalmitoyl-phosphtidylcholine (DPPC), a saturated phospholipid, and L-alpha-dioleoylphosphatidylcholine (DOPC), an unsaturated phospholipid. That is, the trapping efficiency of liposomes was dependent on the number of unsaturated bonds rather than the alkyl chain length of phospholipid molecule and it increased with increasing bulkiness of the molecule. The osmotic response was higher for liposomes prepared using unsaturated phospholipids than for those formed by saturated phospholipids.     

Synthesis of alkyl‐branched fatty acids

Alkyl‐branched fatty compounds are of interest for industrial products in the cosmetics and lubricant areas. In this review, clay‐ and zeolite‐catalyzed isomerizations of unsaturated fatty compounds, especially of oleic acid, are discussed. While clay‐catalyzed reactions give most complex mixtures of dimeric fatty acids and of monomeric so‐called “isostearic acid”, the zeolite‐catalyzed process yields preferentially an isomeric mixture of isostearic acids having the methyl branch on the 8–14 positions of the alkyl chain. Synthetically useful additions of alkyl radicals can only be performed on ω‐unsaturated fatty compounds, whereas perfluoroalkyl iodides were added to fatty compounds with terminal as well as internal double bonds using electron transfer‐initiated radical addition reactions. Electrophilic additions of alkyl carbenium ions generated by decomposition of alkyl chloroformates by ethylaluminum sesquichloride give well‐defined alkyl‐branched oleochemicals with good yields.     

Solvent-Assisted Crystallization of Fatty Acid Alkyl Esters from Animal Fat

An easy and efficient method for the separation of saturated and unsaturated fatty acid mono alkyl esters, prepared from animal fat, was developed. The most efficient separation was achieved by the use of solvents such as methanol and acetone at low temperatures. The dilution of the alkyl esters with 10 times the amount of solvent (10:1 v/w) and storage of the mixture for 4 h at ?22 °C could be defined as optimum conditions. After filtration of the saturated fraction at the corresponding temperature very pure fractions were obtained. For fatty acid methyl esters deriving from tallow, with an initial content of saturated fatty acids of almost 50 %, a saturated ester fraction with only 5 % unsaturated fatty acids and an unsaturated ester fraction with about 9 % of saturated fatty acids could be obtained. The solvent easily could be recovered by distillation. In addition fatty acid ethyl, 1‐propyl, 2‐propyl, 1‐butyl, tert‐butyl and 3‐methyl‐1‐butyl esters were prepared and separated into saturated and unsaturated fractions. All fractions were analyzed according to the fatty acid compositions and showed similar or slightly worse results compared to the methyl esters. The cold filter plugging points of the unsaturated fractions were measured, showing the lowest value for the unsaturated methyl ester fraction at ?26 °C. The fractionation with the use of solvents is an easy tool in order to obtain fatty acid alkyl esters with excellent cold temperature behavior out of animal fat.     

Assembly of 4‐Substituted 3‐Nitro‐1,2,3,4‐tetrahydropyridines via Organocatalytic Michael Addition

An organocatalytic Michael addition of protected 2‐amino‐1‐nitroethanes to α,β‐unsaturated aldehydes followed by treatment with TFA afforded 4‐substituted 3‐nitro‐1,2,3,4‐tetrahydropyridines with good diastereoselectivity and excellent enantioselectivity. Good yields were observed in the case of β‐aryl‐substituted α,β‐unsaturated aldehydes as the substrates, while moderate yields were obtained when β‐alkyl‐substituted α,β‐unsaturated aldehydes were used.     

Studies on the preparation and analysis of glyceryl ether derivatives and the isolation and reductive ozonolysis of unsaturated glyceryl ethers

Glyceryl ethers were identified and quantified by the GLC analysis of their alkyl iodide (special conditions described), acetonide and allyl alkyl ether derivatives. The acetoxy-mercuri-methoxy derivatives of unsaturated glyceryl ether swere separated from saturated glyceryl ethers by TLC and the fractions were analyzed as alkyl iodides. Monoiodides from saturated glyceryl ethers and diiodides from unsaturated glyceryl ethers were also separated by TLC and then analyzed. Allyl alkyl ethers had small retention volumes and these derivatives were separated into pure fractions by preparative GLC. Ozonides were reduced either to alcohols with lithium aluminum hydrodie or to aldehydes with dimethyl sulfide. The alcohols were converted to mono- and diiodides which were separated by TLC and analyzed by GLC. The recovery of n-C₆ and n-C₇ monoiodides was not quantitative. Diiodides and aldehydes were both identified and quantified by GLC. Ozonolysis data suggest that the 16∶1 glyceryl ethers from dogfish liver oil contain 7,8 and 9,10 isomers and the 18∶1 glyceryl ethers contain 9,10 and 11,12 isomers. Presented in part at the AOCS Meeting, Philadelphia, October 1966.     

Über die Darstellung isomerenfreier verzweigter Carbonsäuren

Preparation of Branched Carboxylic Acids Free from Isomers A method for the preparation of branched saturated and unsaturated carboxylic acids, free from isomers, from tertiary γ-lactones by means of alkyl aluminium chlorides is reported. Saturated branched carboxylic acids were obtained in high yields by the reaction with ethyl aluminium chloride, whereas the reaction with diethyl aluminium chloride yielded the unsaturated acids. Splitting of lactones with mixtures of both the ethyl aluminium chlorides gave mixtures of saturated and unsaturated acids. The structure of the unsaturated carboxylic acid was determined by hydrogenation, ozonolysis, iodine value and gas chromatography.     

油墨用酚醛树脂的化学改性研究

对油墨用(烷基)酚醛树脂的化学改性研究进行了综述。分别讨论了(烷基)酚醛树脂的环氧化改性、松香改性、石油树脂改性及其他含不饱和键的化合物或聚合物改性,主要包括改性原理、改性方法及其应用情况。     

The hydrolytic polymerization of ε-caprolactone by triphenyltin acetate

The polymerization of ε-caprolactone (CL) using triphenyltin acetate has been investigated. Polymers with broad MWD were obtained in almost quantitative yield. After an initial induction period, the polymerization showed zero order kinetics with respect to monomer and nearly first order with respect to catalyst. The mechanism of the propagation reaction is proposed to proceed via an ester alcoholysis, with initiation by traces of water. The zero order kinetics are explained as follows: the tin catalyst is coordinated by the cyclic lactone, monomer addition to the polymer chain in the rate-determining step results in formation of an acyclic ester link, which is no longer a strong donor, and leads to a coordinatively unsaturated tin species.     

Influence of fatty acid structure on liquid crystal formation in systems with anionic surfactant,diethyleneglycol ethylether and water

The influence of the fatty acid structure on the formation of transparent gels with lamellar liquid crystal structure, for systems composed of an anionic surfactant, fatty acid, diethyleneglycol ethyl ether and water, was investigated. The influence of the alkyl chain length, for both saturated and unsaturated fatty acids, was considered. Moreover, for a given alkyl chain length, the influence of polyunsaturation was also considered. The results obtained indicate that with saturated fatty acids, it is not possible to form lamellar liquid crystals with the appearance of transparent gels, and that in the case of unsaturated acids, the influence of the alkyl chain length is more important than the degree of unsaturation.     

Comparison of Antioxidant Capacities of Rosmarinate Alkyl Esters in Riboflavin Photosensitized Oil-in-Water Emulsions

Effects of the alkyl chain length of rosmarinate alkyl esters on the oxidative stability in photosensitized oil-in-water (O/W) emulsions were determined by lipid hydroperoxides and headspace volatile analyses. Antioxidant capacities of 20 μM rosmarinate esters with alkyl chain length of 0, 4, 8, 12, 18, and 20 were tested in O/W emulsion containing stripped soybean oil, Tween 20 as an emulsifier, and riboflavin as a photosensitizer. Synergistic or antagonistic effects of 20 μM α-tocopherol in the presence of rosmarinate alkyl esters were also determined. Samples containing rosmarinate with 4 and 8 alkyl esters showed lower lipid hydroperoxides and headspace volatiles than those without rosmarinate and those with 0, 12, 18, and 20 alkyl esters, which indicates that phenolic free radical scavengers showed antioxidant capacities non-linearly in riboflavin photosensitized O/W emulsions. Antagonistic rather than synergistic effects were observed in all rosmarinate alkyl esters with α-tocopherol in current conditions although rosmarinates with 4, 8, and 12 alkyl esters showed better antioxidant capacities than those with other alkyl chain length. The results of this study clearly showed that rosmarinates need the proper length of non-polar groups to show optimum antioxidant capacities in O/W emulsions with Tween 20 as an emulsifier under riboflavin photosensitization.