Ab Initio Study of Structures, Metallotropic 1,2-Shifts and Prototropic 1,2-Shifts of Cyclopentadienyl(trimethyl)silane, -germane and -stannane

Abstract

Molecular structures, metallotropic and prototropic shifts of cyclopentadienyl(trimethyl)silane (1), cyclopentadienyl(trimethyl)germane (2), and cyclopentadienyl(trimethyl)stannane (3) were investigated using ab initio molecular orbital and the Becke, Lee, Yang, and Parr density functional (B3LYP) methods. The results show that the most stable structure of compounds 1-3 has the (CH 3 ) 3 M fragment in the allylic position. The energy barrier of metallotropic shifts in compound 1 is higher than in 2, and in compound 2 higher than in 3, in good agreement with experimental data. The cyclopentadienyl rings in compounds 1-3 are found to be planar but this result contradicts the reported experimental data.

<i>Ab initio</i> and DFT Study of Prototropic and Metallotropic 1,5-Shifts of Isolobal Cyclopentadienyl Derivatives

“…Based on the present results it can be concluded that allylic isomer is the most stable isomer among the mentioned compounds. In addition, it was indicated that prototropic shift is much slower than metallotropic shift 19 . The 1,2-shift and hydrogen migration mechanisms for the Co(CO) 3 and BH 2 were studied using B3LYP/6-311+G** and MP2/6-311+G** levels of theory for compounds 1 and 2.…”

Ab Initio Study of Geminal Steric Hindrance Effects on the Stability of Conformations of Cyclohexane Derivatives

“…In fact, the published literature B3LYP results showed the increasing applicability of density functional theory (DFT) as a successful computational method and now DFT methods are known as reliable approaches for determining activation barriers and molecular energies. 12,13,16,17…”