Tetranuclear ruthenium clusters containing a pseudo-octahedral Ru4S2framework and diaminocarbene ligands

Abstract

The tetranuclear ruthenium clusters [Ru4(CO)6(µ-CO)3(µ4-S)2{C(NHR)2}2]1(R = Pri) and 3(R = Et) and [Ru4(CO)7(µ-CO)3(µ4-S)2{C(NHR)2}]2(R = Pri) and 4(R = Et) were obtained from the thermal reaction of [Ru3(CO)12] with thioureas SC(NHR)2(R = Pri or Et). In the case of diethylthiourea, a trinuclear cluster [Ru3(µ-H)(CO)9(µ3-NEtCSNHEt)]5 was isolated in addition to 3 and 4. The single-crystal X-ray structure analyses of 1 and 2 reveal a pseudo-octahedral Ru4S2 skeleton with three µ-carbonyl bridges in the Ru4 plane; 1 has two terminal diaminocarbene ligands and six terminal carbonyls, whereas there is only one terminal diaminocarbene ligand but seven terminal carbonyls in 2.