Synthesis, characterization, crystal structures and in vitro antimicrobial activities of triorganotin(IV) complexes of azo-dicarboxylates

Abstract Triorganotin(IV) complexes (R = n-butyl, phenyl and methyl) of azo-dicarboxylates were synthesized by reacting bis -tri-n-butyltin(IV) oxide with ( E )-5-((2-carboxyphenyl)diazenyl)-2-hydroxy benzoic acid (L 1 HH′) [compound 1] and tri-organotin(IV) chlorides [R = Ph, Me] with either sodium salt of ( E )-5-((2-carboxyphenyl)diazenyl)-2-hydroxy benzoic acid (L 1 Na) [compounds 2 and 3] or sodium salt of ( E ) - 5-((4-carboxyphenyl)diazenyl)-2-hydroxy benzoic acid (L 2 Na) [compounds 4 and 5] . The complexes were characterized by elemental analysis, UV, IR and NMR-spectroscopy. NMR studies of the triorganotin(IV) complexes indicate that the complexes adopt 4-coordinate quasi tetrahedral geometry in solution state. The structures of complexes 1 and 3 in solid state were characterized by X-ray crystallography. The crystal structure analyses show that the complexes have polymeric structures with distorted trigonal bipyramidal geometry around tin atoms. Classical intra-molecular hydrogen bonds O—H⋯O have been observed in both the complexes. In-vitro antimicrobial activities of the complexes were also screened against various microbes and found to be effective.