Phosphorus-nitrogen compounds. Part 36. Syntheses, Langmuir-Blodgett thin films and biological activities of spiro-bino-spiro trimeric phosphazenes

Abstract

The condensation reactions of hexachlorocyclotriphosphazene (N3P3Cl6, trimer) with the symmetric N2N2 or N2O2 donor type tetradentate bulky ligands (1-4) gave partly substituted spiro-bino-spiro (sbs) (5-8) trimeric phosphazenes. Compounds 5-8 reacted with pyrrolidine, morpholine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD) to give octapyrrolidino-(9-12), morpholino-(13-16) and DASD-substituted cyclotriphosphazenes (17-20). The structures of the phosphazenes have been elucidated using FTIR, MS, H-1, C-13{H-1} and P-31{H-1} NMR, and HSQC spectral data. The molecular and solid-state structures of 5, 6 and 12 were verified by single crystal X-ray diffraction techniques. On the other hand, the ultrathin and highly ordered Langmuir-Blodgett (LB) films of compounds 6, 7, 9 and 12 were also fabricated. The structural characterization of the LB films was made using p-polarized grazing angle (GAIR) and horizontal attenuated total reflectance (HATR) techniques. All the novel phosphazene derivatives were evaluated for antibacterial activities against Gram-positive (G+) and Gram-negative (G-) bacteria and for antifungal activities against yeast strains. In addition, the cytotoxic effects of compounds 9, 13, 15, 16, 19 and 20 were investigated against L929 fibroblast and MDA-MB-231 breast cancer cells. The most active one among these compounds was compound 9 at 6.25 mu g mL(-1) concentration. The interactions between compounds 5-20 and pBR322 plasmid DNA were determined by agarose gel electrophoresis.