Isolation, characterization and anti-tumour properties of novel chiral organotin(IV) complexes of phenanthrolines.

Novel chiral complexes of tin have been synthesized by using amino acids as chiral auxiliary and 1,10-phenanthroline, 4,7-phenanthroline or 1,7-phenanthroline as a secondary ligand. A series of di- and tri-organotin(IV) (LSnR0L') complexes where, L=amino acid (tyrosin and phenylalanine) and L'=1,10-phenanthroline, 4,7-phenanthroline or 1,7-phenanthroline and n = 2 or 3 have been prepared by the conventional methods. Structure elucidation has been done by IR, UV, H-1, C-13 and Sn-119 NMR spectroscopy. All the complexes are air stable and non-electrolytic in nature. On the basis of spectral evidences, it has been concluded that the carboxylic acid of the amino acid is behaving as a monodentate ligand in all these complexes and the complexes are octahedral in shape with a coordination number six around the tin atom. An attempt has been made to correlate structural aspects of the compounds with the biological studies. The complexes have been screened against a number of fungi and bacteria to assess their growth inhibiting potential. The in vitro activity of the synthesized compounds has also examined against Candida albicans (commensal of the human body). Tin complexes incorporating the chelating 1,10-phenanthroline ligand showed a range of activities. The metal free non-chelating ligands 1,7-phenanthroline and 4,7-phenanthroline were inactive and the complexes derived from 1,7-phenanthroline displayed only marginal activity.