Equilibria in complex compounds of N-heterocyclic molecules. Part IV. Complexes of platinum(II) in basic solution

Abstract

We report: (i) reversible spectroscopic changes (electronic and n.m.r.) as a function of pH in solutions containing complex ions of platinum(II) with two 2,2′-bipyridyls or 1,10-phenanthrolines; (ii) lack of proton exchange in the solution of [Pt(phen)₂]²⁺; (iii) similar spectroscopic changes, but lack of proton exchange, in 5-itrophenanthroline; and (iv) the isolation from basic solutions of substances of composition Pt(phen)₂(OH)X (X = Br or Cl). These findings are interpreted in terms of an equilibrium of the co-ordinated N-heterocycle with solvent. This involves reaction at the carbon atom adjacent to the ring nitrogen.