有机化学 ›› 2014, Vol. 34 ›› Issue (2): 349-354.DOI: 10.6023/cjoc201306034 上一篇    下一篇

研究论文

硅硅键与苯环之间的相互作用:不对称取代1,2-二苯基二硅烷的紫外吸收性质

谷广娜, 孙怀林, 周秀中   

  1. 南开大学化学系 天津 300071
  • 收稿日期:2013-06-21 修回日期:2013-10-09 发布日期:2013-10-28
  • 通讯作者: 孙怀林 E-mail:sunhl@nankai.edu.cn
  • 基金资助:

    国家自然科学基金(No.20834002)、天津市自然科学基金(No.08JCZDJC21600)和高等学校博士学科点专项科研基金(No.20090031110012)资助项目.

Interaction of Silicon-Silicon Bonds and Phenyl Rings: UV Absorption Properties of Unsymmetrically Substituted 1,2 Diphenyltetramethyldisilanes

Gu Guangna, Sun Huailin, Zhou Xiuzhong   

  1. Department of Chemistry, Nankai University, Tianjin 300071
  • Received:2013-06-21 Revised:2013-10-09 Published:2013-10-28
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 20834002), the Natural Science Foundation of Tianjin City, and the Research Found for the Doctoral Program of High Education (No. 20090031110012).

苯基二硅烷中硅硅键和苯基之间的相互作用及其所导致的特殊紫外吸收现象,是有机硅化学中的一个重要理论问题. 但是,关于1,2-二苯基二硅烷中两端苯基和硅硅键之间的相互作用,以及这种相互作用与其特殊紫外吸收现象之间的关系,则至今没有得到很好地解决. 为此,合成了一系列不对称取代的二苯基四甲基二硅烷C6H5SiMe2SiMe2C6H4- p-COMe(3),p-MeOC6H4SiMe2SiMe2C6H4-p-COMe(4),C6H5SiMe2SiMe2C6H4-p-NMe25),p-MeOC6H4SiMe2SiMe2C6H4- p-NMe26),并利用1H NMR,13C NMR,IR和元素分析对上述各化合物进行了鉴定. 在此基础上,对这些化合物的紫外吸收光谱进行了研究. 结果发现,化合物36均表现出两个强的长波紫外吸收峰,分别对应于两端取代苯基各自与硅硅键相连时所具有的特征紫外吸收的波长,而不存在由于两端取代苯基之间跨越硅硅键相互作用而导致其紫外吸收发生显著红移的现象. 这表明,传统地利用苯基和硅硅键之间的共轭作用来解释苯基二硅烷特征紫外吸收现象的观点,有必要进行重新检验.

关键词: 苯基二硅烷, 硅硅键, 紫外吸收, σ-π共轭, 电荷转移

The interaction of silicon-silicon-bonds and phenyl-systems in phenyldisilanes and the resulted characteristic UV absorptions have been one of the fundamental issues of organosilicon chemistry. However, the interaction between two phenyl groups and the central silicon-silicon bond in 1,2-diphenyltetramethyldisilanes and its correlation with the characteristic UV absorptions remain uncompletely solved. In this paper, a series of unsymmetric substituted 1,2-diphenyltetramethyldisilanes, namely C6H5SiMe2SiMe2C6H4-p-COMe (3), p-MeOC6H4SiMe2SiMe2C6H4-p-COMe (4), C6H5SiMe2SiMe2C6H4-p-NMe2 (5) and p-MeOC6H4SiMe2SiMe2C6H4-p-NMe2 (6), have been synthesized and characterized by 1H NMR, 13C NMR, IR and elemental analyses, and their UV absorption properties were studied. It is found that each of the compounds exhibits two characteristic absorption bands at the long wavelength region of the UV spectra, which corresponds to the absorptions produced when individual substituted phenyl groups are linked to silicon-silicon bonds. No obvious bathochromic shifts due to interaction between two substituted phenyl groups through the silicon-silicon bond have been observed. This indicates that the traditional explanation of characteristic UV absorptions of phenyldisilanes in terms of conjugation between silicon-silicon bonds and phenyl groups should be re-examined.

Key words: phenyldisilanes, silicon-silicon bonds, UV absorption, σ-&pi, conjugation, charge transfer