Molecular spectroscopy of organometallic compounds: Organotin(IV) tropolonates

The infrared, Raman, and 119Sn Mössbauer spectra of seven organotin tropolonates (R2SnT2), (C6H5)SnT3, and bis tropolonatotin(IV) dichloride have been examined in detail. The diorganotin(IV) compounds have a six-coordinate structure with the two organic ligands occupying either cis (R=CH3, C6H5, and C6H5CH2) or trans (R=C2H5, n-C3H7, n-C4H9) positions. Owing to the asymmetric nature of the tropolone ligand, none of these structures have a center of symmetry in the solid state and both the symmetric and asymmetric Sn–C stretching vibrations are Raman active. The temperature dependence of the recoil-free fraction for the diorganotin(IV) tropolonates has been determined over the temperature range 78?T