Four organotin(IV) complexes derived from 2,6-difluoro-3-(propylsulfonamido)benzoic acid: synthesis, structure, in vitro cytostatic activity and antifungal activity evaluation

Abstract

Four new organotin(IV) complexes, [(Me2Sn)4O2(C10H10F2NO4S)4] (1), [(n-Bu2Sn)4O2(C10H10F2NO4S)4] (2), [Me3SnC10H10F2NO4S] (3) and [n-Bu3SnC10H10F2NO4S] (4) have been synthesized by the reactions of 2,6-difluoro-3-(propylsulfonamido)benzoic acid with R2SnO (R = Me, and n-Bu) or R3SnCl (R = Me, and n-Bu). The four complexes have been characterized by elemental analysis, FT-IR, NMR (1H, 13C and 119Sn), and X-ray crystallography. The X-ray crystallography analyses revealed that the complexes 1 and 2 represent tetranuclear tin ladder-like geometries. In comparison, complexes 3 and 4 exhibit 1D zig-zag chains. Complex 1 constructs a 2D planar structure by NH···O and CH···O intermolecular hydrogen bonding. Complex 2 constructs a 3D supramolecular framework via the CH···O and CH···F intermolecular hydrogen bonding. The 3D supramolecular frameworks of complexes 3 and 4 were formed by SO···H intermolecular hydrogen bonding, respectively. Furthermore, in vitro cytostatic activity of complexes 1–4 against the cervical carcinoma (HeLa) and the hepatocellular carcinoma (HepG-2) cell lines were examined by MTT screening. Results indicated that complexes 2 and 4 exhibited strong cytostatic activity. Meanwhile, the inhibition of complexes 1–4 against five common plant pathogenic fungi in vitro was obtained by the mycelial growth inhibition method, and the results revealed that complex 4 exhibited much stronger inhibition. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs were used to study changes on the fungal morphology for the treatments with complex 4.