IR Spectroscopy of OP−X and Derivatives:  Mistaken Identity on a Large Scale

Abstract

Previous low resolution gas-phase IR spectra of OP-X and related derivatives generated by pyrolysis are critically examined. Density functional calculations at the B3LYP/aug-cc-pVTZ level have been performed for these and similar benchmark molecules where reliable experimental data exist. These theoretical results, comparison with published high-resolution data, and the reassignment of observed bands to well-known chemical species lead to revisions for OCNCN and total rejection of earlier vibrational assignments for OPCl, OPBr, OPI, OPI 3 , OSbF 3 , OSbCl 3 , OPCN, OPSCN, NSCN, and NSSCN.

Electron affinities of heavier phosphoryl and thiophosphoryl halides APX3 (A = O, S and X = Br, I)

“…Recently, Robertson and McNaughton carried out vibrational analyses for OPBr 3 and OPI 3 molecules using B3LYP and MP2 methods and 3-21G** and aug-cc-pVTZ basis sets. 31 Our results for the corresponding species reproduce results of their calculations while providing better consistency with experimental data. However, the differences for SPBr 3 and SPI 3 are larger.…”

The bond dissociation energies of SO3—X– (X = F, Cl, Br, and I)

“…Other work on similar molecules suggests that the closely related B3LYP/6-311+G(d,p) approach gives generally good agreement with experiment without scaling (22), but for the systems studied here, the calculated values are too high (by 7%, 17%, and 14% for SO 3 , SO 3 F -, and SO 3 Cl -, respectively). Because the derived thermochemistry is most sensitive to the ratio of the reactant and product frequencies, unscaled computational results were used for all molecules.…”

The gas-phase thermochemistry of PCl4+: A test of lattice energy calculations

“…B3LYP calculations with the aug-cc-pVTZ basis set [17] give frequencies 5-6% lower than experiment, indicating that the aug-cc-pV(T + d)Z basis set is more accurate for these systems. B3LYP/aug-cc-pVTZ frequencies are typically 0-5% lower than experimental frequencies for this type of system [18,19]. Uncertainties in the derived thresholds due to possible inaccuracies in the frequencies were estimated by multiplying the entire sets of frequencies by 0.9 and 1.1.…”