四氟乙烯齐聚体的反应VII:多氟烷基硫醚的分子内重排及其动力学的研究

本文通过交叉反应、溶剂效应、反应物浓度、截捕实验、动力学参数研究了多氟烷基硫醚的分子内热重排过程.确认并根据Arrhenius方程计算出在四氯化碳溶液中反应的活化能.多氟烷基硫醚分子内重排系经分子内亲核协同过程进行.     

有机硼酸盐的化学II. 三烷基炔基硼酸锂与CO2反应过程中转移烷基的立体构型问题

本文研究了三烷基炔基硼酸锂与CO2 什应过程中转移烷基的立体构型问题,发现在该反应过程中烷基转移时其立体构型保持不变.这一特点对合成具有特定结构的有机化合物有一定意义.     

Titanium-dioxide-mediated photocatalysed reaction of selected organic systems

The photocatalysed reaction of four selected organic systems, namely dichlone (1), 2-amino-5-chloropyridine (2), benzoyl peroxide (3) and 3-chloro perbenzoic acid (4), has been investigated in an acetonitrile/water mixture in the presence of titanium dioxide and oxygen. An attempt has been made to identify the products formed during the photo-oxidation process using the GC/MS analysis technique. The photolysis of dichlone (1) leads to the formation of phthalic anhydride (11) and 1H-indene-1,2,3-trione (10), whereas 2-amino-5-chloropyridine (2) gave rise to 2,2′-diamino bipyridyl (14), 2-pyridinamine (16), 2-hydroxy-5-chloropyridine (18), bipyridyl (19) and 2-amino bipyridyl (21). The photolysis of benzoyl peroxide (3) yielded a mixture of products such as benzoic acid (24), biphenyl (27), biphenyl-4-carboxylic acid (29) and benzoic acid phenyl ester (30). Two intermediate products, as 3-chlorobenzaldehyde (35) and hydroxyl added 3-chlorobenzaldehyde (33), have been identified in the case of 3-chloro perbenzoic acid (4). The products have been identified by comparing the molecular ion and mass fragmentation peaks of the products with those reported in the GC-MS library. A probable mechanism for the formation of the products has been proposed.     

冠硫醚的高效液相色谱分离

由于王冠化合物冠硫醚的结构中含有软硷硫原子,因此选择它来配合作为软酸的过渡金属离子以分离或分析这些金属离子.过去,以冠硫醚为配体与铂系金属的配合作用的报道很少,我们为此进行了冠硫醚的合成,但发现它们难以用常法分离纯化,因而采用了高效液相色谱法(HPLG)分离.用HPLC法分离冠醚化合物的研究报道很少,近年来仅见Bij等对二苯并18-冠-6和二苯并24-冠-8在C_8和C_(18)烷基键合固定相及硅胶上,用水-甲醇等作移动     

N-苯乙烯基糖精的质谱研究

本文对N-苯乙烯基糖精在70eV电子束轰击下质谱的裂解规律进行了研究.这类化合物都有较强的分子离子峰,大部分是基锋,[M-HSO~2]^+是它们的特征碎片.实验证明,糖精母体的SO~2有可能和苯环邻位H或取代基苯环上的H络合而消去HSO~2.当苯乙烯基邻位取代基为NO~2时,由于硝基氧的迁移,使质谱上的m/z119成为基峰.     

氯化二甲基-3,3-二氯-2-丙烯基锍的制备和反应

以二甲硫醚和1,1,3-三氯-1-丙烯反应合成了锍盐2, 经碱处理形成 叶立德1;1不经分离能顺利地对羰基加成, 制得带偏二氯乙烯基的环氧衍生物3-9, 与α,β-不饱和酮反应生成相应的环丙烷衍生物10、11。     

含磷硫键五配位磷化合物的合成研究

在各种不同条件下,五氯化磷与邻苯二硫酚、4-甲基-1,2-苯二硫酚反应均生成五元环亚磷酰氯。在制取含有五氟苯硫基五配位磷化合物时,总是得到五氯苯硫基亚磷酸酯和五氟苯基二硫化物。当3,4-双(三氟甲基)-1,2-二硫杂环丁烯与亚磷酸酯反应时得到含有五个磷硫单键的五配位磷化合物。     

葡萄糖水溶液中碳酸盐热力学研究 1.二氧化碳-碳酸氢钠-氯化钠-葡萄糖-水体系

在278.15～318.15K和一定离子强度范围内,测定了无液接电池Pt,(1-x)H~2+xCO~2│NaHCO~3(m~1),NaCl(M~2),.CO~2(m~3),葡萄糖(m~4)│AgCl-Ag的电动势,利用改进的Harned外推法和我们提出的多项式拟合法确定了二氧化碳在15%葡萄糖水溶液中的一级酸常数K 两种方法所得PK 值在实验误差范围内一致.PK 随温度变化符合经验方程PK =A~1+A~2/T+A~3T,并计算了二氧化碳在葡萄糖水溶液中解离过程的各热力学量.     

An EPR study of thermally and photochemically generated oxygen radicals on hydrated and dehydrated titania surfaces

The formation of a series of oxygen-centred radicals on different TiO₂ samples (P25 and two different rutile materials) under various conditions was investigated using X-band c.w. Electron Paramagnetic Resonance (EPR) spectroscopy. The radicals were formed either on thermally-reduced TiO₂, or by UV irradiation of the oxide under an oxygen atmosphere. The nature and stability of the radicals was also explored as a function of surface hydration. On thermally reduced TiO₂, containing surface and bulk Ti³⁺ centres, oxygen adsorption at 300 K results in the preferential formation and stabilisation of O₂ ^- anions on the P25 surface, but O^- and O₃ ^- anions are generated on the rutile surfaces. Superoxide anions (O^-) and trapped holes (O₂ ^-) were also identified after photo-irradiation of the thoroughly dehydrated TiO₂ samples under oxygen. The O^- anions were only visible at low temperatures under continuous irradiation, while the O₂ ^- anions were stable for days at 300 K. By comparison, on fully hydrated surfaces, no stable oxygen centred radicals could be detected on P25, while O₂ ^- anions were easily observed on the rutile surfaces. On partially hydrated P25, the O^-, O₂ ^- and HO₂ anions were detected after UV irradiation at 77 K; all radicals decayed upon warming to 298 K. On partially hydrated rutile, the O^- and O₂ ^- anions were detected and, unlike the case for P25, were found to be stable for days under the same conditions. The results illustrate the varied formation and stability of the oxygen centred radicals on TiO₂ surfaces depending on the pretreatment conditions.     

羰基过渡金属异核原子簇[(μ-SHgFe~Co(CO|)~9.(μ-CI)]~2的合成及晶体结构

本文报道了羰基异核原子簇, [(μ2-)HgFeCo(CO)~9(μ-CI)]~2的合成及晶体结构。化合物由(μ-S)HgFeCo(CO)~9(μ-CI)双聚而成。双聚分子具有c~2h对称性。在Fe-Fe, Fe-Co之间存在明显的金属-金属键。三核簇中的两个铁原子作为双齿配体与Hg原子配位。并通过HgS二聚形成双三角型簇合物。