Phosphorus-nitrogen compounds: Part 46. The reactions of N3P3Cl6 with bidentate and monodentate ligands: The syntheses, structural characterizations, antimicrobial and cytotoxic activities, and DNA interactions of (N/N)spirocyclotriphosphazenes with 4-chlorobenzyl pendant arm

[Display omitted] •The (N/N)spirocyclotriphosphazenes with 4-chlorobenzyl pendant arm were prepared.•The structures of these compounds were determined using spectroscopic methods.•The crystal structures of four phosphazenes were established.•The antimicrobial and cytotoxic activities of the compounds were investigated.•The interactions between the compounds and pBR322 plasmid DNA were examined. In the present study, the partly and fully-substituted monospiro (4–6, 4a-6d), cis-dispiro (7–9), trans-dispiro (10–15) cyclotriphosphazenes were synthesized for the investigations of their chemical, stereogenic and biological properties. The cis/trans phosphazenes (7–12) have two stereogenic P centers. They are expected to be in meso and racemic forms. In addition, the structures of four compounds were evaluated using X-ray crystallographic data. Compound 13 was found to be a single enantiomer (RR) in the solid state, as also proved with its CD spectrum. The antibacterial and antifungal activities of the phosphazenes were elucidated for against Gram-positive (G+) and Gram-negative (G−) bacteria, and yeast strains, respectively.Of the compounds, 14 exhibits strong antimicrobial activity against most of the tested organisms, especially B. cereus and E. hirae. MBC and MFC values of compounds on different bacterial and fungal species ranged from