Photochemical reaction of Re 2(CO) 10 with tetramethylthiourea; structural characterization of two novel pentarhenium carbonyl complexes containing sulfido and tetramethyldiaminocarbene ligands, [Re 5(CO) 17( μ-R)( μ4-S) 2{C(NMe 2) 2} 2] (R=SH or OH)

Abstract

Photochemical reaction of [Re 2(CO) 10] with tetramethylthiourea [SC{(NMe 2) 2}] has led to the cleavage of the SC bond yielding two novel rhenium carbonyl compounds [Re 5(CO) 17( μ-R)( μ 4-S){C(NMe 2) 2} 2] (R=SH 8 or OH 9). The complexes have been characterised by spectroscopic methods and X-ray crystallography. The structure of 8 is based on a distorted Re 3S 3 octahedral cluster with meridonal arrangement of the three Re and three S atoms. Two of the S atoms are each bound to three Re atoms at the centre and also bonded to a terminally placed Re(CO) 4{C(NMe 2) 2} moiety; the third S atom belongs to a SH group and bridges a pair of the meridonal Re atoms. Only two of the meridonal Re atoms lie within Re–Re bonding distance indicating that Re–Re bonds in [Re 2(CO) 10] have also been cleaved during the reactions. Compound 9 is isostructural with 8, with the OH group replacing the SH group.