Vibrational frequencies and structural determination of cyclotriphosphazene

The normal mode frequencies and corresponding vibrational assignments of cyclotriphosphazene (P3N3) in D3h symmetry are examined theoretically using the Gaussian03 set of quantum chemistry codes. All normal modes were successfully assigned to one of three types of motion (P-N stretch, P-N-P bend, and ring torsion) predicted by a group theoretical analysis. Comparing the vibrational frequencies with IR and Raman spectra available in the literature, scaling factors are derived. Molecular orbitals and bonding are examined.