Synthesis and characterization of 2,5-bis(benzylthio)-1,3,4-thiadiazole complexes with fac-ReBr3(CO)32-

Reactions of 2,5-bis(benzylthio)-1,3,4-thiadiazole (1) with a common organometallic rhenium starting material [NEt4](2)[fac-[Re(I)Br-3(CO)(3)] yielded two distinct types of complexes. Both complexes coordinate only through the nitrogen of the thiadiazole ring. Reaction of 1 with the rhenium starting material alone yielded a bimetallic complex fac-(di-mu-bromo)(mu-2,5-bis(benzylthio)-1,3,4-thiadiazole-kappa N:kappa'N)bis(tri-carbonyl rhenium (I)) (2). The nitrogens of the thiadiazole ring of 1 each coordinate to a different rhenium center combined with two bridging bromide ligands in 2. A "2+1" complex was prepared in a two step process by reacting the rhenium starting material with picolinic acid followed by 1 to yield fac-Re(I)(2,5-bis(benzylthio)-1,3,4-thiadiazole)(CO)(3)(picolinate) (3). Compounds 2 and 3 were characterized by NMR, IR, UV, elemental analysis, and single crystal X-ray diffraction. (C) 2008 Elsevier B.V. All rights reserved.