OXORHENIUM(V) COMPLEXES WITH N-(THIOCARBAMOYL)BENZAMIDINATES, R2TCB- - X-RAY STRUCTURE OF [REO(ET2TCB)2](BPH4).PH3PO

Novel cationic rhenium(V) complexes with N-(thiocarbamoyl)benzamidinato ligands (R2tcb-) with the general formula [ReO(R2tcb)2](BPh4) have been prepared and characterized by elemental analysis, IR and NMR spectroscopy and mass spectrometry. The complexes are brown powders; crystalline products can only be obtained in the presence of triphenylphosphine oxide. [ReO(et2tcb)2](BPh4).OPPh3 has been studied with X-ray diffraction. The compound crystallizes triclinic in the space group P1BAR with a = 9.771(1), b = 16.886(1), c = 17.731(1) angstrom, alpha = 108.91(1), beta = 95.35(1), gamma = 104.36(1)-degrees, V = 2930 angstrom3 and Z = 2. The Re = O bond is 1.663(4) angstrom. The co-crystallization with tripenylphosphine oxide can be understood with the formation of hydrogen bonds between the NH protons of the chelate and the O atom of Ph3PO.