METAL-THIOLATE CHEMISTRY - THE STRUCTURE OF THE FIRST ADAMANTANE-TYPECATION, [(MU-SPH)(6)(HGPPH(3))(4)](2+)

The compound [(mu-SC6H5)6(HgP(C6H5)3}4] [ClO4](2) crystallizes in the triclinic space group Pi as a bis(chloroform) solvate with cell dimens ions a=15.799(4), b=26.813(5), c=15.040(5) Angstrom, alpha=96.35(2), b eta=114.52(2), gamma=100.45(2)degrees and two formula units per cell. The crystal and molecular structures of this salt were solved by X-ray diffraction techniques using 9898 counter data with I > 2.5 sigma(I) recorded at -50(2)degrees C. Refinement of 477 variables by full-matri x least squares converged at an agreement factor R=0.046. The cation h as adamantane-type stereochemistry with a (mu-SPh)(6)Hg-4, cage and fo ur terminal triphenylphosphine ligands. The S-C, vectors of the bridgi ng SC6H5, groups adopt the configuration [aae, aae, aee, aee] with the minimum number of two 1,3-axial, axial substituent interactions. Ther e is a significant flattening of the two Hg3S3 rings with two axial su bstituents into an envelope conformation; each has two torsion angles less than 25 degrees, instead of the ideal values of +/-60 degrees in adamantane. One perchlorate ion is doubly solvated by chloroform molec ules in an unusual, weakly hydrogen bonded, [Clo(4). 2HCCl(3)](-) comp lex.