取代超支化聚硅烷紫外光引发剂研究

以钠缩合法合成的含Si–Cl键的超支化聚硅烷(Cl-HPS)为基础,将其分别与4-羟基二苯甲酮和2-羟基硫杂蒽酮反应,制备了小分子光引发剂取代的超支化聚硅烷BP-HPS和TX-HPS.小分子光引发剂取代的超支化聚硅烷可以不同程度地扩展超支化聚硅烷的紫外吸收.采用实时红外光谱研究了它们引发己二醇二丙烯酸酯(HDDA)紫外光聚合行为.结果表明,小分子光引发剂取代的超支化聚硅烷的自由基引发效率高于未经取代的超支化聚硅烷和它们对应的小分子光引发剂的引发效率.电子自旋共振光谱研究表明,BP-HPS和TX-HPS既可以裂解产生硅自由基,也可以通过硅甲基参与的夺氢反应产生碳中心自由基.     

苯环上氯取代位对四苯基金属卟啉催化烯烃环氧化性能的影响

以苯乙烯、环己烯和反式二苯乙烯为烯烃底物,以双氧水、叔丁基过氧化氢和异丙苯过氧化氢为氧化剂,以苯环上对位和邻位氯取代的四苯基金属卟啉为仿生催化剂,对烯烃的催化环氧化反应进行了对比研究.讨论了不同氯取代位的四苯基金属卟啉对烯烃环氧化性能的影响.实验结果表明,在没有助催化剂存在下,邻位氯代的四(2,6-二氯苯基)铁(锰)卟啉对烯烃的环氧化具有优异的催化性能,烯烃底物的转化率和环氧选择性都比对位氯代的四苯基铁(锰)卟啉高,且反应条件温和.其中FeⅢ(TDCPP)Cl的催化性能最好,环氧化选择性最高,催化氧化苯乙烯时,环氧苯乙烷的选择性达到了90.4%.相同金属离子不同配体的金属卟啉传递氧原子的能力为TDCPP>T(p-Cl)PP>TPP.氧化剂的结构对环氧化物的选择性有较大影响.过氧键连有吸电子基团的异丙苯过氧化氢对环氧化物的选择性最高.根据实验结果,对金属卟啉催化环氧化机理进行了分析.     

模拟细胞色素P-450的仿生氧化反应研究 II.氯合,-5,10,15,20-四苯基卟吩合锰(III)催化下亚碘酰芳烃及其衍生物的结构对环已烷羟化及氯化反应的影响

在氯合,-5,10,15,20-四苯基卟吩合锰(Ⅲ)[TPPMn(Ⅲ)Cl]催化下,带有不同取代基的亚碘酰苯对环己烷的充氧化反应与TPPFe(Ⅲ)Cl催化的结果不同,取代基的电子效应和立体效应对羟化产物(环己醇)的产率无线性相关性,而对氯代产物(氯代环己烷)的产率有良好线性相关性.比较了苯亚碘酸二醋酐、苯亚碘酸单对甲苯磺酸酐和邻、间、对亚碘酰苯甲酸及邻亚碘酰苯甲酸酯的结构对环己烷充氧化反应的影响,表明了它们的结构相似性.     

四苯(基)苯基聚硅烷、乙烯基聚硅烷以及二者共聚物的XPS研究

本文报道四苯(基)苯基聚硅烷、乙烯基聚硅烷以及它们的共聚物的X-射线光电子能谱(XPS)研究。由反映在C_(1s)和Si_(2p)的振起伴峰表征了分子中(P-P)_x、(P-d)_x和(d-d)_x键的存在,同时也探讨了它们各自的XPS价带谱特征。     

Diels-Alder反应在硅橡胶工业及聚硅烷化学中的应用

本文总结了Diels—Alder反应在硅橡胶加工和聚硅烷合成方面的应用,其中包括:(一) 利用该反应合成了含多苯苯基或稠环的硅橡胶交联剂和耐热助剂;(二) 通过该反应建立了硅橡胶新型硫化体系,不外加催化剂;(三) 通过该反应合成了含多苯苯基或稠环的有机硅单体,进而制出许多新型聚硅烷;(四) 探讨了影响硅橡胶各种性能的因素及大芳基对聚硅烷性能的影响。     

Effect of Phenyl CI Substituent Position on the Catalytic Performance for Olefin Epoxidation of Tetraphenylmetalloporphyrins

以苯乙烯、环己烯和反式二苯乙烯为烯烃底物,以双氧水、叔丁基过氧化氢和异丙苯过氧化氢为氧化剂,以苯环上对位和邻位氯取代的四苯基金属卟啉为仿生催化剂,对烯烃的催化环氧化反应进行了对比研究.讨论了不同氯取代位的四苯基金属卟啉对烯烃环氧化性能的影响.实验结果表明,在没有助催化剂存在下,邻位氯代的四（2,6-二氯苯基）铁（锰）卟啉对烯烃的环氧化具有优异的催化性能,烯烃底物的转化率和环氧选择性都比对位氯代的四苯基铁（锰）卟啉高,且反应条件温和.其中FeⅢ（TDCPP）Cl的催化性能最好,环氧化选择性最高,催化氧化苯乙烯时,环氧苯乙烷的选择性达到了90.4%.相同金属离子不同配体的金属卟啉传递氧原子的能力为TDCPP〉T（p-Cl）PP〉TPP.氧化剂的结构对环氧化物的选择性有较大影响.过氧键连有吸电子基团的异丙苯过氧化氢对环氧化物的选择性最高.根据实验结果,对金属卟啉催化环氧化机理进行了分析.     

间位取代四苯基卟啉铁(Ⅲ)的紫外可见光谱及其与二乙胺轴配反应的研究

研究了二氯甲烷溶液中二乙胺(L)与氯合(meso-四-间甲基苯基卟啉)铁(Ⅲ)的轴向配位反应.用光谱法测得不同温度下反应的平衡常数,求得(m-CH_3)TPPFe(Ⅲ)Cl+L=(m-CH_3)TPPFe(Ⅲ)Cl·L反应的标准摩尔焓和摩尔熵.同时,对反应的动力学与反应机理进行了研究.也研究了反应物和产物的紫外可见光谱,并讨论了取代基及轴向配体对铁卟啉紫外可见光谱的影响。     

含N、S官能基聚硅烷*

综述了近年来含N、S官能基聚硅烷的研究进展。介绍了吡啶、联吡啶、吡咯等含N官能基与噻吩、硫代官能团等含S官能基取代聚硅烷的制备和光电性能表征,概括了含N,S官能团聚硅烷的分子设计、物理性能与应用领域。最后展望了含N、S官能团聚硅烷研究的发展方向与应用前景。     

含三氟甲基聚硅烷的合成及其紫外光降解

用Wurtz法合成了聚甲基苯基硅烷、聚(对三氟甲基苯基)(甲基)-甲基苯基硅烷以及聚(对三氟甲基苯基)(苯基)-甲基苯基硅烷3种聚硅烷。用IR、GPC和荧光光谱对产物进行表征,并研究了其紫外光降解性能。从电子结构角度解释了不同聚硅烷在荧光以及紫外光降解行为方面的差异。结果表明,在苯环对位引入吸电子基团三氟甲基有利于紫外光降解的进行,而苯环的增多则会阻碍紫外光降解。     

氯代(对位取代四苯基)卟啉铁(Ⅲ)的轴向配位反应热力学及光谱研究

本文对二氯甲烷溶剂中咪唑(Im)与氯代(对位取代四苯基)卟啉铁(Ⅲ)[Fe(p-X)TPPCl,X=Cl,H,CH_3,OCH_3]的轴向配位反应(1)进行了研究.用光谱法测得了反应(1)的平衡常数,并对反应物和产Fe(p-X)TPPCl+2Im(?)[Fe(p-X)TPPIm_2]+Cl~-物的电子光谱、FeHTPPCl和[FeHTPPIm_2]~+Cl~-的电子自旋共振谱和穆斯堡尔谱进行了测量。研究了取代基效应和轴向配体的影响。     

纤维素在离子液体中的均相乙酰化及其选择性

在1-烯丙基-3-甲基咪唑氯盐(AMIMCl)离子液体中进行了纤维素的均相乙酰化. 酯化剂为乙酸酐和乙酰氯以及加入或不加入催化剂吡啶. 用滴定法确定了产物的取代度(DS), 根据¹³C NMR考察了产物的取代度分布. 结果表明: 酰氯酰化的反应速度比酸酐快; 吡啶能加快乙酸酐的酯化反应, 但减慢酰氯的反应; 使用乙酸酐/吡啶酯化时所得产物具有特殊的取代度分布, 即DS_C-2>> DS _C-3.     

前体法制备单分散遥爪聚乙炔

合成了苯基乙烯基亚砜 (PVSO) ,并以萘 碱金属作为引发剂、丁二酸酐作为终止剂 ,进行阴离子聚合 ,制备出单分散、端羧酸盐的苯基乙烯基亚砜的遥爪聚合物 ,聚合物的功能度基本在 1 6 0以上 .在真空加热条件下 ,聚苯基乙烯基亚砜发生侧基热消除反应 ,从而获得末端为羧酸盐的遥爪聚乙炔     

在负载H3PO4的固体上3,3,4-三甲基-4-戊烯-2-酮的催化合成

3,3,4-Trimethyl-4-penten-2-one has been synthesized by the acylation of 2,3-dimethyl-2-butene with acetic anhydride in the presence of soild-supported H3PO4.By comparison of the acylation reactions of 2,3-dimethyl-2-butene with acetic anhydride over various soilds-supported H3PO4,it was found that K10 clay,silicagel,HY zeolite and HMordenite were good supports.The results obtined indicate that the soild-supported small amounts of H3PO4 possessed higher catalytic activities,For obatining a higher yield of 3,3,4-trimethyl-4-penten-2-one different supports required different modification methods.     

Computational studies of nucleophilic substitution at carbonyl carbon: the S(N)2 mechanism versus the tetrahedral intermediate in organic synthesis

A theoretical study specifically addresses the question of whether nucleophilic addition to the carbonyl groups of acid chlorides, esters, and anhydrides involves an addition-elimination pathway or proceeds by a concerted S(N)2-like mechanism in the absence of the generally assumed tetrahedral intermediate. Density functional calculations [B3LYP/6-31+G(d,p)] establish that chloride ion exchange reactions with both formyl and acetyl chloride proceed by a pi attack on the C=O bond. No discernible tetrahedral intermediate typical of an addition-elimination pathway was found in either case. While a tetrahedral intermediate does exist for the addition of fluoride ion to (Cl)(2)C=O, halide exchange of LiCl with both ClFC=O and (Cl)(2)C=O also proceeds by a concerted S(N)2-like pathway. The formation of a tetrahedral intermediate from the addition of methanol to acetyl chloride is slightly exothermic (4.4 kcal/mol). The ion-dipole complex of methanol weakly bonded to the carbonyl carbon of protonated acetyl chloride is stabilized by 13.8 kcal/mol but does not collapse to a tetrahedral intermediate. When four CH(3)OH molecules are H-bonded to protonated acetyl chloride, a tetrahedral intermediate is not completely formed and this solvated complex more closely resembles the precursor to an S(N)1-type ionization of Cl(-). With six H-bonding methanol molecules, a methanol adds to the carbonyl carbon and a proton relay occurs with formation of a tetrahedral-like structure that immediately loses chloride ion in an S(N)1-like solvolysis. These results corroborate earlier suggestions (Bentley et al. J. Org. Chem. 1996, 61, 7927) that the methanolysis of acetyl chloride does not proceed through the generally assumed addition-elimination pathway with a discrete tetrahedral intermediate but is consistent with ionization of Cl(-). The reaction of methoxide ion with methyl acetate proceeds via a multiple-well energy surface and involves the intermediacy of an asymmetrical species with differing C-OMe bond lengths. Models of synthetic applications of acyl transfer reactions involving anhydrides that form N-acyloxazolidinones also proceed by a concerted S(N)2-type pathway even with the carboxylate leaving group. Concerted transition states were observed for the reactions of each enantiomer of a 1,3-diphenylcycloprop-2-ene carboxylic anhydride by S-3-lithio-4-phenyloxazolidinone. Despite close structural similarities between the diastereomeric transition states, the relative energies correlated closely with the experimental results.     

含间苯基聚醚酮醚酮酮的合成和性能研究

自英国ＩＣＩ公司开发聚醚醚酮（ＰＥＥＫ）并于八十年代初期商品化以来［１］,聚芳醚酮作为一类新型结构的高性能特种工程塑料得到了惊人的发展,不同结构的聚芳醚酮相继出现．Ｊａｎｓｏｎ［２］等以对苯二甲酰氯（ＴＰＣ）和４,４′ 二苯氧基二苯酮（ＤＰＢＰ）为单...     

Bi-acylation of cellulose: determining the relative reactivities of the acetyl and fatty-acyl moieties

The global reaction between acetic anhydride and a fatty acid yields, at equilibrium, an asymmetric acetic-aliphatic anhydride in a medium containing finally: acetic-fatty anhydride, acetic anhydride, fatty acid, acetic acid and fatty anhydride. No solvent or catalyst was used to evaluate the impact of the actual reactivity of the anhydrides. The competition between the formation of acetyl and fatty acyl ester functions was evaluated by determining the ratio of acetyl/fatty acyl groups grafted on solid cellulose. The influence of temperature, reaction time, and length of fatty chain on the total degree of substitution and on the ratio of acetyl/fatty acyl ester functions was investigated. For the first time, a correlation has been established between esterification and the length of the aliphatic chain of the fatty acid. Reactivity of the medium decreased with the number of carbons in the fatty acid, raised to the power 2.37.     

Chemical transformations of 3‐amino‐2‐quinolones

In order to find new antimalarial drugs, an exploration about the chemical properties of the starting compounds 3‐amino‐6‐chloro‐4‐phenyl‐1H‐quinolin‐2‐one ( 1 ) and 3‐amino‐4‐methyl‐1H‐quinolin‐2‐one ( 2 ) was developed. Acylation with acyl chloride, sulfonyl chloride and acetic anhydride were carried out. Despite a previous report [2], when acetyl chloride or acetic anhydride were assayed on 1 , only the diacetyl derivative 7 was obtained. When this compound was heated at reflux temperature in a mixture of acetic acid and acetic anhydride, it was transformed in the oxazoloquinoline 8 . Further reactions of the acyl derivatives with diazomethane afforded 1‐methylated compounds. Compound 2 gave the imine 16 by condensation with 4‐nitrobenzaldehyde.     

2-聚苯乙烯磺酰基乙醇树脂的合成及其在海因和脲固相成中的应用

合成了一种新型的聚合物载体—2-聚苯乙烯磺酰基乙醇，并研究其在固相有机合成中应用，聚苯乙烯亚磺酸钠树脂（1）在相转移催化剂BU4NI和助催化KI的作用下，与氯乙进行砜化反应，得到含羟基功能基的2-聚苯乙烯磺酰基乙醇树脂2。树脂2用Boc保护的氨基酯化，封闭树脂上未反应的羟基，用酸脱保护并用三乙胺中和，再与异（硫）氰酸苯酯反应生成聚合生物支载的脲树脂6树脂6用酸解脱得到海因和硫代海因化合物，用碱处理树脂6是得到取代的脲和硫脲，优化了合成反应的全过程，探讨了树脂在酸性和碱性条件下的解脱方法，结果表明，2-聚苯乙烯磺酰基乙醇树脂易与羧基形成含酯键的连接桥，连接桥在强酸性和碱性条件下均可解脱得到产物。     

甲壳素类液晶高分子的研究Ⅵ.邻苯二甲酰化壳聚糖中酰胺酸取代度对液晶性的影响

通过控制不同反应时间和邻苯二甲酸酐 壳聚糖的摩尔比制备不同取代度的邻苯二甲酰化壳聚糖(PHCS) .用FTIR研究了反应机理和产物结构 ,观察到PHCS含两类取代即酰胺酸取代和酰亚胺取代 .反应时间较短时主要为前者 ,取代度表示为DS1 ;反应时间较长时主要为后者 ,取代度表示为DS2 .对PHCS在二氯乙酸 (DCA)中的液晶行为观察 ,结果表明 ,PHCS的临界浓度随DS1 的增加而显著增加 .DS1 对PHCS临界浓度的影响明显大于DS2 的影响 .基本上为酰胺酸取代的PHCS的临界浓度高于溶解度 ,以至于观察不到     

Acyl Iodides in Organic Synthesis: V. Reactions with Carboxylic Acid Esters

Acyl iodides react with alkyl, alkenyl, and aralkyl esters derived from saturated, unsaturated, and aromatic mono- and dicarboxylic acids in the absence of a catalyst. The reaction involves cleavage of the OR bond and formation of organic iodide RI (including CH₂=CHI) and one or two symmetric carboxylic acid anhydrides. Phenyl acetate reacts with benzoyl iodide to give acetyl iodide and phenyl benzoate as a result of cleavage of the (O=)C–O bond. The reaction of diethyl fumarate with acetyl iodide is accompanied by cis– trans isomerization to afford maleic anhydride. In the reactions of acetyl iodide with diethyl oxalate and diethyl malonate, CO and CO₂ and CO₂ and polyketene are formed, respectively, in addition to ethyl iodide and acetic anhydride. Ethyl esters of strong organic acids, e.g., ethyl trihaloacetates, failed to react with acyl iodides under analogous conditions.