Ab initio Study on Formation Mechanism of Spiro-Si-Heterocyclic Ring Compound Involving Ge from H2Ge=Si: and Formaldehyde

作者：Lu, Xiu-hui^*; Wang, Dang-sheng; Ming, Jing-jing

来源：Chinese Journal of Chemical Physics, 2016, 29(2): 193-198.

DOI：10.1063/1674-0068/29/cjcp1507139

• H2Ge=Si
• Four-membered Ge-heterocyclic ring silylene
• Spiro-Si-heterocyclic ring compound
• Potential energy profile

H2Ge=Si: and its derivatives (X2Ge=Si:, X=H, Me, F, Cl, Br, Ph, Ar,...) are new species. Its cycloaddition reactions are new area for the study of silylene chemistry. The cycloaddition reaction mechanism of singlet H2Ge=Si: and formaldehyde has been investigated with the MP2/aug-cc-pVDZ method. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule is that two reactants firstly form a four-membered Ge-heterocyclic ring silylene through the [2+2] cycloaddition reaction. Because of the 3p unoccupied orbital of Si: atom in the four-membered Ge-heterocyclic ring silylene and the pi orbital of formaldehyde forming a pi -> p donor-acceptor bond, the four-membered Ge-heterocyclic ring silylene further combines with formaldehyde to form an intermediate. Because the Si: atom in the intermediate undergoes sp(3) hybridization after transition state, then the intermediate isomerizes to a spiro-Si-heterocyclic ring compound involving Ge via a transition state. The result indicates the laws of cycloaddition reaction between H2Ge=Si: or its derivatives (X2Ge=Si:, X=H, Me, F, Cl, Br, Ph, Ar,...) and asymmetric pi-bonded compounds are significant for the synthesis of small-ring involving Si and Ge and spiro-Si-heterocyclic ring compounds involving Ge.

• 出版日期2016-4
• 单位济南大学