Porous palladium aminophosphates: synthesis, characterization, antimicrobial and cytotoxicity studies

Abstract

Novel palladium aminophosphates have been synthesized at room temperature employing palladium acetate, orthophosphoric acid and aliphatic amines. The PNPAP, PNOAP and PNDDAP obtained were characterized by various spectral and physico-chemical techniques. Small angle powder X-ray diffraction patterns show that PNDDAP is probably mesoporous. The SEM images of PNPAP, PNOAP and PNDDAP show typical layered, flake and tubular like morphologies. The presence of–Pd–O, Pd–N–,–P–O, P–N vibrations in the framework of palladium aminophosphates was confirmed by infrared and Raman spectral studies. Palladium in tetrahedral coordination was confirmed from UV-Vis DRS studies in the frameworks of PNPAP, PNOAP and PNDDAP. The PNPAP and PNDDAP show two 31P MAS NMR peaks which indicate the existence of two crystallographically non equivalent tetrahedrally co-ordinated phosphorous atoms. The PNPAP, PNOAP and PNDDAP were evaluated for biological applications. Only PNDDAP exhibits potent antimicrobial and nematicidal activity on M. incognita. All the palladium containing aminophosphates show DNA cleavage activity on lDNA. The in vitro anticancer studies reveal that PNPAP and PNDDAP show activity only on the HL60 cell line. PNOAP shows good anticancer activity on HL60 and MCF7 cell lines and moderate activity on the HeLa cell line.