The UV photolysis of teh permethylatedlinearpolysilanes Me(Me2Si)nMe (I), with n = 4 to 8, in cyclohexane at, or al little above, room temperature has been found to proceed simultaneously by two different routes, one of these involves contraction of the chain with loss of dimethylsilylene species to produce octamethyltrisilane which was usually very resistant to the photolysis), while the other comprises
The preparation of several permethylated linear polysilanes. From octasilane to dodecasilane
作者:Makoto Kumada、Mitsuo Ishikawa、Sajiro Maeda
DOI:10.1016/s0022-328x(00)93628-3
日期:1966.2
Five new permethylatedlinearpolysilanes of the formula CH3[Si(CH3)2]nCH3, where n is equal to 8, 9, 10, 11 and 12, have been prepared from the co-condensation of appropriate chlorosilanes using sodium-potassium alloy as condensing agent in a benzene-ligroin or benzene-n-heptane mixture. These compounds are all white crystalline substances. The melting points display a regular progression as the number
由合适的氯硅烷与钠共缩合,制备了五种新的式CH 3 [Si(CH 3)2 ] n CH 3的全甲基化线性聚硅烷,其中n等于8、9、10、11和12。 -钾合金作为苯-古丁胶或苯-正庚烷混合物中的缩合剂。这些化合物都是白色结晶物质。熔点随着硅原子数量的增加而显示出规律的变化,这与该系列化合物的奇数和偶数结构的熔点交替出现的较低同系物的熔点形成了鲜明的对比。
Aluminium chloride-catalysed skeletal rearrangement of permethylated linear polysilanes
作者:M. Ishikawa、M. Kumada
DOI:10.1039/c2970000157a
日期:——
Permethylatedlinearpolysilanes, Me(Me2Si)nMe undergo skeletal rearrangement to branched-chain isomers very easily in the presence of aluminium chloride in boiling benzene.
Full details of a study on the reactions of oligosilanes with isocyanides promoted by a palladium catalyst are described. Heating a mixture of oligosilanes and excess 2,6-disubstituted aryl isocyanide in the presence of palladium(II) acetate led to the complete insertion of isocyanide into all silicon-silicon linkages, giving oligo(silylimine) derivatives. The oligo(silylimine)s have been isolated and characterized so far in the complete insertion reaction with oligosilanes up to a hexasilane. Use of the limiting amount of isocyanide permitted insertion of isocyanide into predominantly the terminal silicon-silicon linkages. The mode of the insertion reaction depends on the substituent at the silicon, e.g., tetrasilanes with phenyl groups on the internal silicon atoms favorably underwent the insertion reaction at the terminal silicon-silicon linkages, resulting in the partial insertion. The bulkiness of the ortho substituents on the aromatic isocyanide was also found to have much influence on the insertion; hence, 2,6-diisopropylphenyl isocyanide favored the partial insertion. New skeletal rearrangement of oligosilanes took place in a palladium-catalyzed reaction of substituted aryl isocyanide with tetra- and hexasilanes, forming 3,3-bis(silyl)-l-aza-2, 4-disilacyclobutane derivatives. The rearrangement, which is unique and intriguing in that the product is properly reconstituted from four fragments of the tetrasilane and two fragments of the isocyanide, was promoted in the copresence of a tert-alkyl isocyanide.
ISHIKAWA MITSUO; IYODA JUN; IKEDA HARUHIKO; KOTAKE KAZUNORI; HASHIMOTO TO+, J. AMER. CHEM. SOC., 1981, 103, NO 16, 4845-4850