The crystal and molecular structure of the binuclear complex [(μ-S)-α,α'-{(2-Mercapto-4-methylbenzene-1,3-diyl)di(methylidyne)di(azino)}bis(cyclohexanemethanol)ato(3–)]-(μ-1-propylimidazolato-C⁽⁴⁾,N⁽³⁾)-dipalladium(II)-ethanol (1/0.75)

Abstract

The crystal and molecular structure of the 1-propylimidazolate bridged binuclear complex, LPd₂(primid) has been determined by single-crystal X-ray diffraction techniques at 20ºC; disordered ethanol molecules are also present in the lattice. The quinquedentate ligand L^3- is formally the trianion α,α'-{(2-mercapto-4-methylbenzene-1,3-diyl)di(methylidyne)di(azino)bis(cyclohexane-methanol)ato(3 -). Crystals of LPd₂ (primid) are triclinic, P1, with a 7.078(2), b l3.615(3), c 17365(3) Å, α 78.52(2), β 80.21(2) and γ 83.83(2)º.

The structure was solved by conventional Fourier methods and refined by full-matrix least-squares procedures to convergence with R and R_w 0.053 obtained for the 4133 statistically significant structure amplitudes.

The ligand sidearms are essentially equivalent with both palladium centres displaying similar distorted square-planar geometries, the separation being 3.605 Å. The propylimidazolate bridging group is comfortably accommodated within the binuclear framework and displays a geometry typical of metal complexes of imidazole and its derivatives. Coordination to the palladium centres occurs through C4 and N3, a bridging mode not previously characterized by X-ray crystallography, and one which illustrates the remarkable stability and flexibility of the binuclear LPd₂⁺ core.