Solution aggregation of platinum(ii) triimine methyl complexes

Abstract

The NMR chemical shifts of [Pt(tpy)(CH₃)](PF₆) (1) and [Pt(mbzimpy)(CH₃)](PF₆) (2), where tpy = 2,2′;6′2′′-terpyridine and mbzimpy = 2,6-bis(N-methylbenzimidazol-2-yl)pyridine, in room-temperature DMSO-d₆ displayed concentration dependence as a result of formation of dimers. Quantification of these dimers, expressed by equilibrium constant (K), shows a greater tendency of 2 to aggregate in solution. Structural conformations of these dimers were confirmed by 2D ¹H–¹H NOESY; the results explicitly suggest a head-to-tail stacking arrangement of molecules in dimers.