Investigations on the synthesis, characterization and electrochemical properties of [2FeNi] cluster complexes

To better investigate the coordination chemistry of [2Fe2S] cluster complexes and nickel complexes with the ligand of monosulfide bis(diphenylphosphino)(N-R)amine, four [2FeNi] cluster complexes Fe-2(CO)(6)(mu(3)-S)(2)[Ni(Ph2PN{P(S)Ph-2)CH2CH(CH3)(2))] (1), Fe-2(CO)(6)(mu(3)-S)(2)[Ni(Ph2PN{P(S)Ph-2)(CH2)(3)CH3)] (2), Fe-2(CO)(6)(mu(3)-S)(2)[Ni(Ph2PN{P(S)Ph-2)CH(CH3)(2))] (3) and Fe-2(CO)(6)(mu(3)-S)(2)[Ni(Ph2PN{P(S)Ph-2) CH2CH2CH3] (4) have been synthesized by reactions of [(Ph2P)N{P(S)Ph-2)R)]NiCl2 and [2Fe(2)S] cluster complex Fe-2(CO)(6)(SH)(2). Complexes 1-4 have been determined by elemental analysis, IR, NMR, UV, TGA and X-ray single diffraction analysis. In all the complexes, the iron atoms are approximately coordinated in a square-pyramidal geometry and each nickel atom is coordinated in a slightly distorted planar geometry by one P and three S atoms. Moreover, 1-4 were observed to be catalysts for H-2 evolution in the presence of weak acid CH3CO2H under electrochemical conditions. (C) 2021 Published by Elsevier Ltd.