Palladium and platinum complexes with N,N-dimethylselenourea

Palladium and platinum dihalides reacted with N,N-dimethylselenourea (dmsu) yielding complexes of the general formulae [M(dmsu)(4)]X(2), [M(dmsu)(3)X]X, [Pd(dmsu)(2)X(2)] and Pt(dmsu)(1.5)X(2), (M = Pd or Pt; X = Q or Br); which were characterized by IR and proton NMR spectroscopy and thermogravimetric analysis (TD, DTG and DTA). The 1:4 adducts can be obtained in two crystalline forms, depending on the crystallization medium. In particular, [Pd(dmsu)(4)]Cl-2 crystals have been obtained in deuterated chloroform, which differ from those of [Pd(dmsu)(4)]Cl-2 . 0.5EtOH samples obtained in ethanol/n-pentane. In the latter case a solvent molecule is interspersed in the crystal packing. The crystal structures of both modifications have been determined by X-ray crystallography and refined to R = 0.042 and R = 0.062, respectively. In both structures the Pd(dmsu)(4)(2+) complex cation is approximately square planar with Pd-Se bonds ranging from 2.43 to 2.46 Angstrom. An extensive net of NH ... Cl bonds is present in the crystal packing of the compounds.