Ultrasonic‐assisted synthesis and biological evaluation of a nano‐rod diorganotin phosphonic diamide: Precursor for the fabrication of SnP2O7 nano‐structure

Nanorods of a diorganotin phosphonic diamide with formula [Sn(CH3)2(Cl)2(L)2]{L = C6H5(O)P(NHC6H11)2} have been synthesized by sonochemical processes at different concentrations without any surfactant or capping agent. The structure and morphology of the prepared complex were investigated by using SEM-EDAX, XRD, DLS, UV–Vis and FT-IR spectroscopy. Nanoparticles with well-defined rod shapes and sizes in the range 30–40 nm have been obtained. Also bulk form of the titled complex was synthesized and characterized by 1H, 13C, 31P, 119Sn NMR, UV–Vis and FT-IR spectroscopy and compared with its nano-size. The thermal stabilities at bulk and nano-size scale have been studied by thermal gravimetric (TG) and differential thermal analysis (DTA). Further, SnP2O7 nanoparticles were synthesized by direct calcination at 730 °C under air atmosphere and characterized using XRD, SEM, and TEM. From XRD measurements, we determined the mean size of the crystallites about 27.4 nm. It is found that the size and morphology of the tin pyrophosphate nano-structures are dependent upon the particles size of precursor compound as well. Two different forms of metal coordination compound (1a, 1b) and the corresponding ligand (L) were screened for their antibacterial activity against the selected Gram-positive and Gram-negative bacteria, showing bactericidal activity for complexes 1a and 1b. In vitro cytotoxicity of compounds was studied against human carcinoma cell lines, A2780 (ovarian cancer) and PC-3 (prostate cancer). Results indicated that 1a and 1b possess relatively strong cytotoxic activity against cancer cells with IC50 values ranging from 93.2 to 376.2 μM for two exposure time (24 and 48 h).