Organotin Complexes of 4-Pyrones

Organotin(IV) complexes with 3-hydroxy-2-methyl-4H-pyran-4-one (HMa), of formulae R2SnMa2 (R = Me or Ph), Me2SnMaX (X = Cl or Br), Ph2SnMaCl and Ph3SnMa, have been synthesized along with the 2,6-dimethyl-4H-pyran-4-one (DMP) 1:1 adducts Me2Sn(DMP)X2 (X = Cl or Br), Ph2Sn(DMP)Cl2, Ph3Sn(DMP)Cl and PhSn(DMP)Cl3. Moreover, the Me2Sn(DMP)2Cl2 complex has been obtained. The compounds have been characterized by ir and nmr (1H and 13C) spectroscopy and by thermogravimetric (TG and DTA) analysis. DMP acts as a weak donor towards organotin moieties, the complexes releasing ligand molecules in most solvents, whereas the data for the maltolato complexes support the presence of chelated ligand. DMP or HMa complexes display a more or less marked volatility, sublimation occurring after melting. At higher temperatures sample degradation replaces the sublimation process.