Pairwise H<sub>2</sub>/D<sub>2</sub> Exchange and H<sub>2</sub> Substitution at a Bimetallic Dinickel(II) Complex Featuring Two Terminal Hydrides
作者:Dennis-Helmut Manz、Peng-Cheng Duan、Sebastian Dechert、Serhiy Demeshko、Rainer Oswald、Michael John、Ricardo A. Mata、Franc Meyer
DOI:10.1021/jacs.7b08629
日期:2017.11.22
M[LNi2(H)2], M = Na (Na·2) and K (K·2), which were isolated after reacting the precursor complex [LNi2(μ-Br)] (1) with MHBEt3 (M = Na and K). Crystallographic characterization showed the two hydride ligands to be directed into the bimetallic pocket, closely interacting with the alkali metal cation. Treatment of K·2 with dibenzo(18-crown-6) led to the separated ion pair [LNi2(H)2][K(DB18C6)] (2[K(DB18C6)])
具有两个 β-二酮亚胺结合位点的隔室配体支架 HL 产生了一系列双核镍 (II) 二氢化物复合物 M[LNi2(H)2], M = Na (Na·2) 和 K (K· 2),在前体复合物 [LNi2(μ-Br)] (1) 与 MHBEt3(M = Na 和 K)反应后分离。晶体学表征显示两个氢化物配体被引导到双金属口袋中,与碱金属阳离子密切相互作用。用二苯并(18-crown-6)处理K·2导致分离的离子对[LNi2(H)2][K(DB18C6)](2[K(DB18C6)])。Na·2 或K·2 与D2 的反应通过一系列1H 和2H NMR 实验进行了研究,揭示了一个不寻常的成对H2/D2 交换过程,该过程同时涉及两个Ni-H 部分而没有H/D 加扰。DFT 计算提供了一张机械图,这表明双金属裂缝内的两个末端氢化物很容易重组,中等焓势垒约为 62 kJ/mol,得到 H2 和反铁磁耦合的 [LNiI2]