SYNTHESIS AND REACTIVITY OF RHENIUM(III) SULFIDE BIS(ACETYLENE) IODIDE COMPLEXES

Rhenium(III) sulfide bis(acetylene) iodide complexes, Re(S)I(RC=CR)(2) (R = Et (2a); R = Me (2b)), have been synthesized by addition of boro n sulfide, B2S3, to the corresponding oxo compounds Re(O)I(RC=CR)(2) ( R = Et (la); R = Me (1b)) in methylene chloride. The solid state struc ture of 2b contains pseudotetrahedral molecules, with the vertices occ upied by sulfur and iodine atoms and the centroids of the acetylenes, very similar to the structure of the oxo precursor Ib. The spectral an d physical properties of 2 are also quite similar to those of 1. The s ulfide complexes are much less stable than their oxo analogs, decompos ing at 25 degrees C over a few days. Reactions occurring at the sulfid e ligand of 2 are quite similar to those involving the oxo ligand of 1 . However, reagents that replace the iodide ligand in 1 for the most p art cause decomposition of the sulfide complexes 2. The sulfide-ethyl complex Re(S)Et(MeC=CMe)(2) is formed at law temperatures from Re(O)Et (MeC=CMe)(2) and B2S3 but decomposes within minutes at 25 degrees C. C rystal data for 2b: C8H12IReS; orthorhombic,Pna2(1); a = 7.213(1) Angs trom, b = 10.859(2) Angstrom, c = 14.258(2) Angstrom, V = 1116.8(6) An gstrom(3); Z = 4.