The reaction of [Ni(C₂H₄)(dtbpe)] with 1-alkyl-1,2-diphospholes afforded [Ni(1-alkyl-1,2-diphosphole)(dtbpe)] complexes. Both DNMR experimental and DFT calculation results have shown that in solution these complexes are in an equilibrium of two P–P side-on η²-coordinated 1-alkyl-1,2-diphosphole isomers. In one form, unusual η² bonding occurred at a P₂–P₁ side, presumably at the expense of a vicinal P₂–C₁ π bond, and it could be characterized as a phosphametallacycle with the formal oxidation state of Ni(II). In the second isomer with the Ni(0) state, Ni bonds to the ligand through two σ interactions with phosphorus lone pairs. The P₂ chemical shift, being heavily dependent on structure, can be used to monitor these isomer populations.

中文翻译：

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含镍磷杂环镍配合物的结构多样性和动力学

[Ni（C ₂ H ₄）（dtbpe）]与1-烷基-1,2-二磷醚的反应得到[Ni（1-烷基-1,2-二磷酰基）（dtbpe）]配合物。既DNMR实验和DFT计算结果表明，在溶液中的这些复合物是在两个P-P侧上η的平衡²配位的1-烷基-1,2- diphosphole异构体。在一种形式中，不寻常的η ²接合发生在为P ₂ -P ₁侧，大概在邻位P的费用₂ -C ₁π键，可以表征为具有Ni（II）形式氧化态的金属磷环。在具有Ni（0）状态的第二个异构体中，Ni通过与磷孤对的两个σ相互作用与配体键合。P ₂化学位移在很大程度上取决于结构，可用于监测这些异构体的数量。