Platinum (II) and palladium (II) complexes of N-benzoyl-N'-propylthiourea (H_2L): synthesis and geometric isomer distribution of [M(H_2L-S)_2X_2] (M=Pt~(II)or Pd~(II); X=Cl~-, Br~- or I~-); crystal structure of trans-[Pd(H_2L-S)_2Br_2]

摘要

A systematic study of the synthesis and cis/trans isomer distribution for simple [M(H_2L-S)_2X_2] complexes (M=Pt~(II)or Pd~(II); X=Cl, Br or I; H_2L=N-benzoyl-N'-propylthiourea has shown that the pure cis-[Pt(H_2L-S)_2Cl_2] complex is obtained prior to recrystallization. The cis-[Pt(H_2L-S)_2Cl_2] complex undergoes facile isomerization in a variety of organic solvents, the equilibrium cis/trans distribution of which depends on solvent polarity. The corresponding bromo- and iodo-complexes of Pt~(II) tend toward mainly the trans isomers, as do the corresponding palladium (II) complexes. The crystal structure of trans-[Pt(H_2L-S)_2Br_2] has been determined which is the first examples of a palladium (II) complex in which the potentially chelating ligand is bound through the S atom only.