Synthesis and coordination chemistry of RC(E)NHPPh2 (E = O or S; R = H2N, Ph, or Py): X-ray structure of [Pt{H2NC(S)NHPPh2}2] 2Cl 0.5MeOH

H2NC(S)NHPPh2 1, H2NC(O)NHPPh2, PhC(O)NHPPh2 2, and (C5H4N)C(O)NHPPh2 3 were prepared from reaction of PPh2Cl with thiourea, urea, benzamide, and nicotinamide, respectively. Compound 1 reacts readily with [PtCl2(COD)] to form [Pt{H2NC(S)NHPPh2}(2)](2+) 2Cl(-)0.5MeOH 4. X-ray crystallography of 4 revealed the platinum atom is coordinated through sulphur and phosphorus atoms forming two five-membered rings which consist of five different atoms in a planar conformation ie. 4 can be classed as a 'true' heterocycle. 4 adopts a hydrogen bonded structure using all of the available N-H protons and the chloride counterions to form a sheetlike array with the phenyl rings of the phosphorus centres lying above and below the 'sheets'. (C) 1999 Elsevier Science Ltd. All rights reserved.