INORGANIC CHEMISTRY, vol.63, no.39, pp.18389-18407, 2024 (SCI-Expanded)
The reactions of monospirocyclotriphosphazenes (1 and 2) with N-methyl-1,3-diaminopropane gave unsymmetrical cis-(3 and 5) and trans-(4 and 6) dispirocyclotriphosphazenes. Trans-cis-trans (tct) (7 and 11), cis-cis-cis (ccc) (8 and 12), trans-trans-cis (ttc) (9 and 13), and cis-trans-trans (ctt) (14) trispirocyclotriphosphazenes were obtained from the reactions of 3 and 5 and 4 and 6 with N-methyl-1,3-diaminopropane. cis-Dispirocyclotriphosphazenes (3 and 5) exist as "pseudomesoracemates", while trans-dispirocyclotriphosphazenes (4 and 6) are in "racemates". The existences of cis-3 and trans-4 as "pseudomesoracemate" and "racemate" were confirmed by P-31 NMR spectra recorded by the addition of "chiral solvating agent (CSA)". X-ray crystallography proved that the absolute configurations of each enantiomer of cis-5 and trans-6 are SS ' and RS '. Trispirocyclotriphosphazenes tct, ttc, ccc, and ctt exist as racemates, pseudomesoracemate, and meso forms. Furthermore, Hirshfeld surface analysis of the crystal structures of cis-5 and trans-6 revealed that the most significant contribution to crystal packing comes from H