Phosphorus-nitrogen compounds: Part 66. Syntheses, structural and chiral properties of multiheterocyclic cis and trans bis (benzylspiro-N/N) cyclotriphosphazenes

•The cis and trans benzylspiro(N/N)cyclotriphosphazenes were synthesized.•The spectral analyses of all the phosphazenes were presented.•The absolute configurations of the two compounds were examined by X-ray crystallography.•Chirality of the phosphazenes was interpreted using 31P NMR upon the addition of CSA.•Hirshfeld surface analysis was carried out for two compounds.