Abstract X2C=Sn: compounds (X=H, Me, F, Cl, Br, Ph, Ar) are new species. The cycloaddition reactions of X2C=Sn: are also a new study field of unsaturated stannylene chemistry. The mechanism of cycloaddition reaction between singlet Me2C=Sn: and ethene was investigated for the first time using the MP2/GENECP (C, H in 6-311++G**; Sn in LanL2dz) method. From the potential energy profile, it was predicted that the reaction has one dominant channel in which the 5p unoccupied orbital of Sn: in Me2C=Sn: and the π orbital of ethene form a π→p donor-acceptor bond in an intermediate product. Instability of the intermediate product results in its isomerization to a four-membered ring of stannylene. The four-membered stannylene further combines with ethene to form another intermediate product that further isomerizes to a spiro-Sn-heterocyclic ring compound.

中文翻译：

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Me2C=Sn:与乙烯的环加成反应形成螺-Sn-杂环化合物的理论研究

摘要 X2C=Sn：化合物（X=H、Me、F、Cl、Br、Ph、Ar）是新物种。X2C=Sn:的环加成反应也是不饱和亚锡化合物的一个新研究领域。使用MP2/GENECP（C, H in 6-311++G**; Sn in LanL2dz）方法首次研究了单线态Me2C=Sn:与乙烯之间的环加成反应机理。根据势能分布，预测该反应具有一个主导通道，其中 Sn: 在 Me2C=Sn: 中的 5p 未占据轨道和乙烯的 π 轨道在中间产物中形成 π→p 供体 - 受体键。中间产物的不稳定性导致其异构化为亚锡四元环。四元亚锡基进一步与乙烯结合形成另一种中间产物，该产物进一步异构化为螺-锡-杂环化合物。