Optical charge transfer in the ion pair paraquat2+[Au(CN)2]−

Abstract

In aqucous solution paraquat(2+) (N,N'-dimethyl-4,4'-bipyridinium(2+)) and [Au(CN)(2)](-) form an ion pair (K similar to 90 M-1) which shows an outer-sphere [Au(CN)(2)](-) to paraquat(2+) charge transfer (CT) abaorption at lambda(max) = 331 nm. A band analysis yields a potential of E-o similar to 3.2 V for the one-electron oxidation of [Au(CN)(2)](-). Accordingly, Au(I) is a very weak CT donor. (C) 2000 Elsevier Science S.A. All rights reserved.