Synthesis and structure of two isomers of a molybdenum(II) 2-butyne complex stabilized by bioinspired S,N-bidentate ligands.

The synthesis and structural determination of two isomers of the molybdenum(II) complex (η 2 -but-2-yne)carbonylbis[2-(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)benzenethiolato-κ 2 N,S]molybdenum(II), [Mo(C 11 H 12 NOS) 2 (C 4 H 6 )(CO)] or Mo(CO)(C 2 Me 2 )(S-Phoz) 2 , are presented. The N,N-cis-S,S-trans isomer 1 shows quite different bond lengths to the metal atom [Mo-N = 2.4715 (10) versus 2.3404 (11) Å; Mo-S = 2.4673 (3) versus 2.3665 (3) Å]. In the N,N-trans-S,S-cis isomer 2, which is isotypic with the corresponding W complex, the Mo-N bond lengths [2.236 (2) and 2.203 (2) Å], as well as the Mo-S bond lengths [2.5254 (8) and 2.5297 (8) Å], are almost the same.