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化学学报
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化学学报 ›› 2006, Vol. 64 ›› Issue (19): 1974-1980. 上一篇    下一篇

研究论文

R2C＝GeH2和R2Ge＝CH2结构与成键特征的理论研究

耿志远*, 贾宝丽, 王永成, 姚琨, 方冉, 张兴辉   

  1. (西北师范大学化学化工学院 甘肃省高分子材料重点实验室 兰州 730070)
  • 投稿日期:2006-01-06 修回日期:2006-04-30 发布日期:2006-10-14
  • 通讯作者: 耿志远

Theoretical Study on the Structure and Bonding Character of the R2Ge＝CH2 and R2C＝GeH2

GENG Zhi-Yuan*; JIA Bao-Li; WANG Yong-Cheng; YAO Kun; FANG Ran; ZHANG Xing-Hui   

  1. (Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070)
  • Received:2006-01-06 Revised:2006-04-30 Published:2006-10-14
  • Contact: GENG Zhi-Yuan

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用密度泛函理论(DFT), 在B3LYP/6-31＋G(d, p)水平上研究了取代基对二取代锗烯R2Ge＝CH2和R2C＝GeH2 [R＝H, OH, NH2, SH, PH2, F, Cl, Br, (NHCH)2, CH3, (CH)2]的影响. 研究发现π供电子取代基在碳上时更能引起分子结构在锗端的锥型化. 碳原子上的π电子给予取代基的给电子效应越强, R2C的单-三态能量差越大, π电子的反极化效应就越强, 使得化合物的结构在锗端发生的弯曲越明显, 从而使得弯曲结构更稳定. 和前人的计算相比, 碳上的给电子取代基对GeH2结构影响大于它对SiH2的影响.

关键词: 密度泛函理论, 锗烯, 反极化效应

Substituent effects on the disubstituted heavier analogues of R2C＝GeH2 and R2Ge＝CH2 [R＝H, OH, NH2, SH, PH2, F, Cl, Br, (NHCH)2, CH3, (CH)2] were investigated using density functional theory [B3LYP/6-31＋G(d, p)]. The major conclusion was that the stronger the π-donation of the substituents, the larger the ΔEST of CR2 and the stronger the π-electron reversed-polarization effect. As the π-electron reversed-polarization effect increased, the distortion of GeH2 fragment increased, and the stability of the bent structure increased. In addition, the π-electron-donating substitution at the carbon atom was more effective at inducing a bent structure than at the Ge atom. In contrast to the R2C＝SiH2 system, the π-electron-donating substituents at the carbon atom have more effective influence on inducing GeH2 a bent structure than that of SiH2.

Key words: density functional theory (DFT), germene, reversed polarization effect