Synthesis, structural, and spectroscopic study of rhenium(III) and rhenium(V) 4,6-dimethylpyrimidine-2-thiolate/triphenylphosphine mixed complexes: Crystal and molecular structure of *C3H6O and

Article abstract of DOI:10.1007/BF01185388

4,6-dimethylpyrimidine-2(1H)-thione reacts with rhenium(V) precursors trans (X = Cl, Br) in acetone, to afford two classes of crystalline pyrimidinethiolate/triphenylphosphine mixed complexes: trans-IIIX2(C6H7N2S)(PPh3)2>*C3H6O and VOX(C6H7N2S)(PPh3)> (X = Cl, Br).The crystal structures of trans-*C3H6O (I) and (II) have been determined from single-crystal diffractometer data and refined to R factors of 0.0496 and 0.0365, respectively. (I) crystallizes in the triclinic space group P<*> with a = 16.875(4), b = 13.969(7), c = 9.510(2) Angstroem, α = 81.78(2) deg, β = 85.15(12) deg, γ = 107.97(8) deg and Z = 2.The coordination geometry around the rhenium center exhibit mutually trans phosphine groups and chloride ligands disposed trans to the nitrogen and sulfur donors of the pyrimidine thiolate ligand which form a four-membered chelate ring with the metal. (II) crystallizes in the monoclinic spase group P2₁/c with a = 12.554(3), b = 10.501(1), c = 19.200(5) Angstroem; β = 106.54(2) deg and Z = 4.The rhenium atom presents a very distorted octahedral configuration with a chlorine atom trans to phosphine ligand in the axial position and the N,S-chelate ligand in the equatorial plane with the sulfur donor atom trans the Re=O_oxo group.The compounds were characterized also by means of ir and nmr spectroscopic measurements; reaction pathways are discussed on the basis of structural data.