The bonding interactions and electronic structure of a diphosphine pincer ligand featuring an N-heterocyclic phosphenium/phosphido (NHP^±) central moiety with nickel are explored. Treating Ni(COD)₂ with the pincer ligand [PPP]Cl in the presence of a two-electron phosphine donor ligand PMe₃ generates chlorophosphine complex (PP^ClP)Ni(PMe₃) (2a). The cationic Ni complex [(PPP)Ni(PMe₃)][BPh₄] (3a) can be prepared by subsequent halide abstraction from 2a with NaBPh₄. The assignment of 3a as a Ni⁰/NHP⁺ complex, based on analysis of structural parameters and computational investigations, lies in contrast to its previously reported group 10 M^II/NHP^– (M = Pd, Pt) analogues. The activation of O–H bonds across the Ni–P^NHP bond is demonstrated by the addition of isopropanol to afford the metal hydride species [(PP^OiPrP)Ni(PMe₃)(H)][BPh₄] (4). Notably, the installation of a P–H bond in the NHP unit by treatment of 2a with LiAlH₄ yields (PP^HP)Ni(PMe₃) (6). The ambiphilic nature of the P–H bond was demonstrated through reactivity studies of P–H bond cleavage in comparison to a Pd analogue (PP^HP)Pd(PPh₃) (8).

中文翻译：

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与第 10 组类似物相比，镍 (0) N-杂环磷络合物的电子和结构变化

探索了具有 N-杂环磷/磷 (NHP ^± ) 中心部分和镍的双膦钳形配体的键合相互作用和电子结构。在双电子膦供体配体 PMe ₃存在的情况下，用钳形配体 [PPP]Cl处理 Ni(COD) ₂生成氯膦络合物 (PP ^Cl P)Ni(PMe ₃ ) ( 2a )。阳离子 Ni 络合物 [(PPP)Ni(PMe ₃ )][BPh ₄ ] ( 3a ) 可以通过随后用 NaBPh _4从2a中提取卤化物来制备。3a的归属为 Ni ⁰ /NHP⁺ complex，基于结构参数分析和计算研究，与之前报道的 10 M ^II /NHP- ⁽ M = Pd, Pt) 类似物形成对比。通过添加异丙醇得到金属氢化物物种 [(PP ^{O i Pr} P)Ni(PMe ³ ) ₍ H)][BPh ₄ ] ( 4 ). 值得注意的是，通过用 LiAlH _4处理2a在 NHP 单元中安装 P-H 键产生 (PP ^H P)Ni(PMe ₃ ) ( 6). ^{与 Pd 类似物 (PP H} P)Pd(PPh ₃ ) ( 8 )相比，通过 P-H 键裂解的反应性研究证明了 P-H 键的双亲性质。