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论文类型：期刊论文

发表时间：2021-02-02

发表刊物：DALTON TRANSACTIONS

卷号：49

期号：7

页面范围：2151-2158

ISSN号：1477-9226

摘要：By employing X(CH2CH2S-)(2) (X = S, tpdt; X = O, opdt; X = NPh, npdt) as bridging ligands, four thiolate-bridged dinickel complexes supported by phosphine ligands, [(dppe)Ni(mu-13 kappa SSS ':22 kappa SS-tpdt)Ni(dppe)][PF6](2) (1[PF6](2), dppe = Ph2P(CH2)(2)PPh2), [(dppe)Ni(mu-13 kappa SSN:22 kappa SS-npdt)Ni(dppe)][PF6](2) (2[PF6](2)) and [(dppe)Ni(t-Cl)(mu-13 kappa SSX:22 kappa SS-C4H8S2X)Ni(dppe)][PF6] (3[PF6], X = S; 4[PF6], X = O) were facilely obtained by the salt metathesis reaction. These four thiolate-bridged dinickel complexes have all been fully characterized by spectroscopic methods and X-ray crystallography. In 2[PF6](2), elongation of the Ni-N bond distance, possibly caused by steric hindrance, indicates that the pendant nitrogen group shuttles between the two nickel centers in solution, which is evidenced by P-31{H-1} NMR spectroscopic results. Furthermore, these thiolate-bridged dinickel complexes have all been proved to be electrocatalysts for proton reduction to hydrogen. Notably, complex 2[PF6](2) featuring a pendant amine group in the secondary coordination sphere exhibits the best catalytic activity at a relatively low overpotential.