POLAR INTERACTION-INDUCED NEW PHYSICAL PROPERTIES OF POLYSILANES

极性相互作用引起的聚硅烷的新物理性质

基本信息

批准号：
10640564
负责人：
OKA Kunio
金额：
$ 1.98万
依托单位：
OSAKA PREFECTURE UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

Polar polysilanes with general formula of {R-Si-R'}_n, where R and/or R' represents alkyl, aryl or ethereal groups such as -(CH_2)_3-O-(CH_2CH_2O)_m-R, m=0-3, -(CH_2)_3-O-Ph, -(CH_2)_4-O-C_3H_7, (CH_2)_5-O-C_2H_5, and -(CH_2)_6-O-CH_3, were prepared by wutz-type coupling reaction of the corresponding dichlorosilanes. Most of the prepared polysilanes became soluble in polar solvents such as THF, CH_3CN and alcohols. Polysilanes with oligo-ethereal side groups were found to be water-soluble and show diverse polar interaction with polar solvents as well as ionic species. The first solvatochromism was observed for polysilanes of [CH_3-Si-(CH_2)_3-O-(CH_2CH_2O)_m-R (m=0-3) ; they show continuous red shift by decreasing the polarity of solvent. Unusual discontinuous type of solvatochromism was also found for poly(bis(4-propoxybutyl) silane and analogues when they make strong hydrogen bonding with hexafluoro-2-propanol. The polar side groups in the polysilanes were found to yield ionic complex with LiClO_4 in the solid state. Thermochromic behavior of theses complexes was highly dependent on the ratio of Li/Si ; red-shift was induced on cooling when the Li/Si was small while blue-shift was induced when the ratio was >4. Thermochromic behavior of the above polar polysilanes were compared with the hydrogen bond induced solvatochromism and found that there were no direct similarity between these polar-interaction induced chromotropisms. As the extension of the research, a new cooling rate dependent thermochromism was found for many polydialkylsilanes.

极性聚硅烷，通式为{R-Si-R'}_n，其中R和/或R'代表烷基、芳基或醚基，如-(CH_2)_3-O-(CH_2CH_2O)_m-R，m=0 -3、-(CH_2)_3-O-Ph、-(CH_2)_4-O-C_3H_7、(CH_2)_5-O-C_2H_5，和-(CH_2)_6-O-CH_3,通过相应的二氯硅烷的wutz型偶联反应制备。大多数制备的聚硅烷可溶于极性溶剂，例如THF、CH_3CN和醇。具有低聚醚侧基的聚硅烷被发现是水溶性的，并且与极性溶剂以及离子物质表现出多种极性相互作用。 [CH_3-Si-(CH_2)_3-O-(CH_2CH_2O)_m-R (m=0-3)聚硅烷首次出现溶剂化显色现象；它们通过降低溶剂的极性而表现出连续的红移。当聚(双(4-丙氧基丁基)硅烷及其类似物与六氟-2-丙醇形成强氢键时,也发现了不寻常的不连续型溶剂化变色现象。聚硅烷中的极性侧基被发现与LiClO_4形成离子络合物。这些配合物的热致变色行为高度依赖于Li/Si的比例；当Li/Si较小而蓝移较大时，会引起红移。将上述极性聚硅烷的热致变色行为与氢键引起的溶剂致变色现象进行比较，发现这些极性相互作用引起的变色行为之间没有直接相似性。许多聚二烷基硅烷都发现了依赖热致变色现象。