The coordination of N,N-diethyl-N'-p-tolylthiourea to polynuclear rhenium carbonyl complexes

The reactions of Re-2(CO)(9)(NCMe) and Re-3(CO)(10)(CH3CN)(2)(mu-H)(3) with S=C(NEt(2))N(H)(p-tolyl) have yielded the new compounds Re-2(CO)(9)[S=C(NEt(2))N(H)(p-tolyl)] (1) and Re-3(CO)(10)[mu-SC(NEt(2))N(H)(p-tolyl)](mu-H)(3) (2) in 89% and 98% yields, respectively. Compounds 1 and 2 were characterized by single-crystal X-ray diffraction analyses. Compound 1 contains an S-coordinated S=C(NEt(2))N(H)(p-tolyl) ligand terminally coordinated in an equatorial coordination site on one of the rhenium atoms. Compound 2 contains the first example of an S-coordinated bridging thiourea grouping. When solutions of 1 were heated to 97 degrees, it was transformed to the new compound {Re(CO)(3)[mu-SC(N-p-tolyl)(NEt(2))]}(2) (3) plus Re-2(CO)(10). Compound 3 is a centro-symmetrical dimer of the unit Re(CO)(3)[SC(N-p-tolyl)(NEt(2))] in which the sulfur atom bridges the two rhenium atoms. The tolyl-substituted nitrogen atoms are coordinated to the rhenium atoms to form two Re-S-C-N rings.