Synthesis and electrochemistry of [Pt(tame)2]4+: crystallographic analysis of bis[1,1,1-tris(aminomethyl)ethane-N,N′]platinum(II) bis(tetrachlorozincate) dihydrate

Abstract

Reaction of K₂PtCl₆ with the tripodal ligand tame [1,1,1-tris(aminomethyl)ethane] in dimethylformamide catalysed by K₂PtCl₄ afforded the octahedral bis(tridentate ligand) [Pt(tame)₂]⁴⁺ ion. The cyclic voltammogram of [Pt(tame)₂]⁴⁺ in aqueous media showed an irreversible reduction of the six-co-ordinate platinum(IV) species to Pt^II and bulk electrochemical reduction of the [Pt^IV(tame)₂]⁴⁺ ion quantitatively produced a square planar platinum(II) complex [Pt(tame)₂]²⁺. Crystallographic analysis of the protonated complex [Pt^II(Htame)₂][ZnCl₄]₂·2H₂O, showed two dissociated nitrogen atoms on opposite sides of the PtN₄²⁺ co-ordination plane which has typical Pt^II–N bond lengths (2.042(6) Å). The routes to the formation of the [Pt^IV(tame)₂]⁴⁺ ion and its reduced product are addressed.