REACTIONS OF CRYPTAND-SOLUBILIZED NASH IN APROTIC-SOLVENTS WITH THE GROUP-6B METAL HEXACARBONYLS - X-RAY STRUCTURAL-ANALYSIS AND LIGAND LABILITY STUDIES OF THE ISOLATED M(CO)5SH- ANIONS
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The reaction of cryptand-solubilized NaSH with the group 6B metal hexacarbonyls provides the metallo thiol derivatives [Na-kryptofix-221][M(CO)5SH] in good yield. Although the intermediacy of a metallo carboxylic acid species is implied, no direct evidence for such a transient was obtained. This reaction is contrasted with the analogous process of cryptand-solubilized KOH with M(CO)6 (M = Cr, Mo, W) in aprotic solvent. The thiol complexes were characterized spectroscopically, and the chromium derivative was subjected to single-crystal X-ray diffraction analysis. Crystals of [Na-kryptofix-221][Cr(CO)5SH] crystallize in the orthorhombic space group Pbca with cell dimensions a = 13.45 (3) , b = 20.067 (3) , and c = 20.725 (4) . The structure was refined to values of R1 = 0.046 and R2 = 0.052 for 37 atoms (36 anisotropic) and 2635 reflections with I > 3(I). The thiol ligand was found to be a strongly CO-labilizing ligand, on a par with good oxygen donor bases and better than halide ions. The origin of the labile carbon monoxide ligand was established to be cis to the SH ligand via 13C NMR spectroscopy. The proton on the thiol ligand was observed to readily undergo exchange with H2O in acetonitrile solvent. 1982, American Chemical Society. All rights reserved.