Interconversion between square-planar palladium(ii) and octahedral palladium(iv) centres in a sulfur-bridged trinuclear structure.

Treatment of fac-[Rh(apt)3] (apt = 3-aminopropanethiolate) with Pd2+ gives an S-bridged trinuclear complex, [Pd{Rh(apt)3}2]4+ ([1]4+), which is interconvertible with [Pd{Rh(apt)3}2]2+ ([2]2+). This interconversion is accompanied by a drastic change between the PdIV centre with an S6 octahedral geometry in [1]4+ and the PdII centre with an S4 square-planar geometry in [2]2+.