Oxidative addition of dihydrogen across a metal–metal bond to form reactive metal hydrides in homogeneous catalysis is known for transition metals but not for zinc(I)–zinc(I) bond as found in Carmona’s eponymous dizinconene [Zn₂Cp*₂] (Cp* = η⁵-C₅Me₅). Dihydrogen reacted with the heteroleptic zinc(I)–zinc(I) bonded cation [(L₂)Zn–ZnCp*][BAr₄^F] (L₂ = TMEDA, N,N,N′,N′-tetramethylethylenediamine, TEEDA, N,N,N′,N′-tetraethylethylenediamine; Ar^F = 3,5-(CF₃)₂C₆H₃) under 2 bar at 80 °C to give the zinc(II) hydride cation [(L₂)ZnH(thf)][BAr₄^F] along with zinc metal and Cp*H derived from the intermediate [Cp*ZnH]. DFT calculations show that the cleavage of dihydrogen occurs through a highly unsymmetrical transition state. Mechanistic studies agree with a heterolytic cleavage of dihydrogen as a result of the cationic charge and unsymmetrical ligand coordination. To explore the existence of zinc(I) hydride, thermally unstable hydridotriphenylborate complexes of zinc(I) [(L₂)Zn(HBPh₃)–ZnCp*] (L₂ = TMEDA, TEEDA; TMPDA, N,N,N′,N′-tetramethyl-1,3-propylenediamine) have been prepared by salt metathesis and were shown to undergo fast exchange with both BPh₃ and [HBPh₃]⁻.

中文翻译：

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杂配二锌 (I) 阳离子的锌-锌键引起的二氢裂解

在均相催化中，二氢通过金属-金属键氧化加成形成反应性金属氢化物，这一点对于过渡金属是已知的，但对于卡莫纳的同名二锌酮烯 [Zn ₂ Cp* ₂ ]中发现的锌 (I)-锌 (I) 键则不然。 Cp* = η ⁵ -C ₅ Me ₅ )。氢气与杂配锌(I)–锌(I)键合阳离子 [(L ₂ )Zn–ZnCp*][BAr ₄ ^F ] (L ₂ = TMEDA, N , N , N′ , N ′ -四甲基乙二胺，TEEDA , N , N , N ' , N ' -四乙基乙二胺；Ar ^F = 3,5-(CF ₃ ) ₂ C ₆ H ₃ )在2巴和80℃下生成氢化锌(II)阳离子[(L ₂₎ )ZnH(thf)][BAr ₄ ^F ] 以及锌金属和衍生自中间体 [Cp*ZnH] 的 Cp*H。 DFT 计算表明，氢的裂解是通过高度不对称的过渡态发生的。机理研究同意由于阳离子电荷和不对称配体配位而导致二氢异裂。为了探索氢化锌(I)的存在，热不稳定的氢化三苯基硼酸锌(I)配合物[(L ₂ )Zn(HBPh ₃ )–ZnCp*] (L ₂ = TMEDA, TEEDA; TMPDA, N , N , N ′，N'-四甲基-1,3-丙二胺）通过盐复分解制备，并被证明可以与 BPh ₃和 [HBPh ₃ ] ^-进行快速交换。