In vitro biological studies and structural elucidation of organotin(IV) derivatives of 6-nitropiperonylic acid: Crystal structure of {[(CH2O2C6H2(o-NO2)COO)SnBu2]2O}2

Six organotin(IV) compounds with general formulae R3SnL, R = Me (2), Ph (6), R2SnL2, R = Me (1), Et (3), n-Oct (5), [((R2SnL)2O)2], R = Bu (4), L = 6-nitropiperonylate, have been prepared. The newly synthesized compounds have been characterized by elemental analysis, FT-IR and multinuclear NMR (1H, 13C and 119 Sn). The structure of 4 has been determined by single crystal X-ray crystallography which is triclinic with the space group P1¯. The crystal structure contains centrosymmetric dimer distannoxane with planar central four-membered Sn2O2 core. The 6-nitropiperonylate ligand shows different modes of coordination with Sn, as a result the central Sn2O2 core is fused with two four-membered (Sn(1)–O(1)–Sn(2)–O(13)) and two six-membered (Sn(1)–O(13)–Sn(2)–O(8)–C(9)–O(7)) rings. The endocyclic Sn(2) is six coordinated in a skew trapezoidal bipyramidal environment while exocyclic Sn(1) is five coordinated with distorted trigonal bipyramidal geometry. The ligand acid and synthesized organotin compounds were also screened for antibacterial, antifungal, brine-shrimp lethality and potato disc antitumor activities. Results of bioassay demonstrate that organotin derivatives are in general more active than the ligand acid.

Graphical abstractSix organotin(IV) compounds containing 6-nitropiperonylate ligand were synthesized and characterized by spectroscopic and single crystal X-ray analysis (for compound 4). The newly synthesized compounds and ligand acid were also screened for biological activities such as antibacterial, antifungal, brine-shrimp lethality and potato disc antitumor.Figure optionsDownload full-size imageDownload as PowerPoint slide