Structural elucidation and bioassays of newly synthesized pentavalent antimony complexes

Abstract Antimony (V) organometallics ( 1 – 5 ) have been synthesized with general formula [SbR′ 3 (O 2 CR) 2 ], where R' = phenyl, p -tolyl and O 2 CR are substituted cinnamates. These complexes have been characterized by FT-IR analysis, multinuclear ( 1 H, 13 C) NMR spectroscopy and single crystal X-ray diffraction analysis. The crystal structures of [Sb(phenyl) 3 (4-ClC 6 H 4 C 2 H 2 O 2 C) 2 ] ( 1 ) and [Sb( p -tol) 3 (4-OCH 3 C 6 H 4 C 2 H 2 O 2 C) 2 ].CHCl 3 ( 5 ) displayed distorted geometry between trigonal bipyramidal and square pyramidal with monomeric structure at a five coordinated Sb center. Starting reagents and complexes were evaluated for anticancer, antileishmanial, antibacterial and alpha amylase inhibition potentials. It was observed that complexes 3 , 4 and 5 showed significant (p  Leishmania tropica KWH23 promastigotes and HepG2 cell lines respectively. Antibacterial activity of compound 3 was also significant against E. coli (MIC: 5.55 μg/mL), K. pneumoniae (MIC: 16.66 μg/mL), S. aureus (MIC: 5.55 μg/mL) and P. aeruginosa (MIC: 50 μg/mL). Hence, these new antimony complexes can act as good drug candidates.