Synthesis,characterization, structural elucidation and biological screening of some bis(diisobutyldithiophosphato)antimony(III) complexes

Abstract

Seven complexes of type (C₄H₉ⁱ-O)₂PS₂]₂SbR have been synthesized by the reaction of chlorobis(diisobutyldithiophosphato)antimony(III) with mixed thio and/or oxo donor ligands in 1:1?M stoichiometry, where R?=?SC₆H₅, OOCC₆H₅, SCH₂COOH, SOCCH₃, OOCCH₃, SC₆H₄COOH and OOC(OH)C₆H₄. These newly synthesized derivatives have been characterized by different physicochemical (elemental analysis (C, H, S, Sb), melting point, molecular weight determination), spectral (UV, IR, NMR (¹H, ¹³C and ³¹P)) studies, as well as ESI mass, thermal, powder XRD and biological studies. In the final step of weight loss in thermogravimetric analysis, occurring in the range of 245–505?°C, the degradation of the C₆H₃CO moieties takes place and antimony sulfide (1/2?Sb₂S₃) is obtained as remaining material, which is useful in various aspects. Bonded to antimony the diisobutyldithiophosphato substituent behaves as an anisobidentate ligand, which is confirmed through spectral analysis. Powder XRD studies indicate that these compounds crystallize in a monoclinic crystal system with an unit cell volume of ～7074–7162 ų forming nano ranged (9.69–15.69?nm) crystallites. From the antimicrobial screening tests, bis(diisobutyldithiophosphato)antimony(III) thioglycolate (compound 3) has shown a maximum zone of inhibition (19?mm) against E. coli at 200?μg mL^?1 concentration.