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

Four new organotin(IV) complexes, [(Me2Sn)(4)O-2(C10H10F2NO4S)(4)] (1), [(n-Bu2Sn)(4)O-2(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 (H-1, C-13 and Sn-119), 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 N-H center dot center dot center dot O and C-H center dot center dot center dot O intermolecular hydrogen bonding. Complex 2 constructs a 3D supramolecular framework via the C-H center dot center dot center dot O and C-H center dot center dot center dot F intermolecular hydrogen bonding. The 3D supramolecular frameworks of complexes 3 and 4 were formed by S-O center dot center dot center dot 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.