The primary products in reactions of laser-ablated group 5 metal atoms with ethane were identified in argon matrix IR spectra and characterized via density functional theory computations. The second- and third-row transition metals Nb and Ta produced insertion, metallacyclopropane, vinyl trihydrido, and anionic ethylidyne complexes (CH₃CH₂–MH, (CH₂)₂–MH₂, CH₂═CH–MH₃, and CH₃C≡MH₃^–), while the first-row transition metal V yielded only the insertion and metallacyclopropane products. The energetically higher ethylidenes and neutral ethylidynes (CH₃CH═MH₂ and CH₃CMH₃) were not detected. The unique anionic ethylidynes are the most stable anionic species in the Nb and Ta systems. Evidently back-donation from the metal center to the C–C π* orbital is stronger than that in the group 6 metal analogue but weaker than that in the corresponding group 4 metal complex. The C–M bond for the Nb and Ta ethylidyne anions is a true triple bond.

中文翻译：

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观察和CH表征₃ CH ₂ -MH，（CH ₂）₂ -MH ₂，CH ₂ = CH-MH ₃，和CH ₃ -C≡MH ₃ ^-通过用乙烷5族金属原子的反应所产生的

在氩气基体红外光谱中鉴定了激光烧蚀的5族金属原子与乙烷反应的主要产物，并通过密度泛函理论计算对其进行了表征。第二和第三行过渡金属Nb和Ta产生插入，metallacyclopropane，乙烯基trihydrido和阴离子乙川络合物（CH ₃ CH ₂ -MH，（CH ₂）₂ -MH ₂，CH ₂ = CH-MH ₃，和CH ₃ C≡MH ₃ ^- ），而第一行过渡金属V仅产生的插入和metallacyclopropane产品。能量较高的亚乙基和中性亚乙炔基（CH ₃ CH 2MH ₂和CH ₃ C MH ₃）没有被检测到。独特的阴离子乙炔是Nb和Ta系统中最稳定的阴离子物质。显然，从金属中心向C–Cπ*轨道的反向捐赠比第6组金属类似物强，但比相应的第4组金属络合物弱。Nb和Ta乙炔阴离子的C–M键是真正的三键。