Solid-state electrochemistry of a semiconducting MMX-type diplatinum iodide chain complex

Abstract

Electron-transfer-facilitated dissolution, ion insertion, and desorption associated with an MMX-type quasi-one-dimensional iodide-bridged dinuclear Pt complex (MMX chain) have been investigated for the first time. K 2(NC3N)[Pt2(pop)4I]·4H 2O (1) (NC3N2+ = (H3NC 3H6NH3)2+; pop = P2H 2O52-) is a semiconductor with a three-dimensional coordination-bond and hydrogen-bond network included in the chain. The cyclic voltammetry of 1 was studied by using 1-modified electrodes in contact with acetonitrile solutions containing electrolyte. The chemical reversibility for oxidation of 1 depended on the electrolyte cation size, with large cations such as tetrabutylammonium (Bu4N+) being too large to penetrate the pores formed by the loss of K+ and NC 3N2+ upon oxidation. The potential for reduction of 1 decreased as the cation size increased. The presence of the acid induced additional well-defined processes but with gradual solid dissolution, attributed to the breaking of the coordination-bond networks. © 2014 American Chemical Society.