Synthesis and structural properties of (diamine)platinum (II) complexes of itaconic acid

Abstract

New zwitterionic (diamine)platinum(II) complexes A(2)Pt(ita) (A(2)=2,2-dimethyl-1,3-propanediamine (dmpda), tetrahydro-4H-pyran-4,4-diylbis( methylamine) (thpdma), trans-(+/-)-1,2-diaminocyclohexane (dach), ethylenediamine (en); ita = itaconate) have been synthesized and characterized by means of NMR spectroscopy and X-ray analysis. The platinum atom adopts a square-planar arrangement, in which the itaconate ligand is coordinated to the platinum atom through one carboxylate and the ethylene groups. The ethylene group occupies the fourth coordination site of the square plane, which intersects the midpoint of the C-C bond axis, but the bond axis is not perpendicular to the square plane because of its chelated ring strain. Such a chelation mode is retained without linkage isomerism in aqueous solution up to 70 degrees C. (C) 1998 Elsevier Science S.A.; All rights reserved.