Redetermination of di-μ-sulfido-bis-{[(2R)-2-acet-oxy-2-amino-ethane-1-thiol-ato-κN,S]oxidomolybdenum(V)}.

The structure of the title compound, [Mo(2)(C(4)H(8)NO(2)S)(2)O(2)S(2)], has been redetermined. Besides obvious differences between the original [Drew & Kay (1971 ▶). J. Chem. Soc. A, pp. 1851-1854] and the current unit-cell parameters, some packing features of the structure are also different; these findings are the result of significant improvements in the precision and accuracy of the present structure analysis. The two Mo atoms in the dimeric complex have very similar distorted trigonal-bipyramidal environments. Each Mo atom is bonded to an S atom and to an N atom of an l-cysteine ester ligand, to a terminal O atom and to two S atoms which bridge to the adjacent Mo atom [Mo⋯Mo separation = 2.8191 (2) Å]. N-H⋯O(carbon-yl) and N-H⋯O(terminal) hydrogen-bonding inter-actions consolidate the crystal packing. During the synthesis, the originally employed l-cysteinate ligand has been converted to the l-cysteinate methyl ester ligand. Since this reaction does not take place without tin(IV) chloride, it is clear that tin(IV) chloride acts as a catalyst for the reaction.