Structural Stability and Vibrational Analyses of Haloselenonyl Azides, XSeO2-NNN, where X is F, Cl, Br

Wolfgang Förner,Hassan Badawi,Zaki Seddigi

doi:10.3390/i6090230

Abstract

The structural stability of haloselenonyl azides was investigated by quantum mechanical Møller-Plesset perturbation theory of second order and density functional theory calculations. The 6-311+G** basis set was used to include polarization and diffuse functions in the calculations at the DFT-B3LYP level. The potential scans for the rotation of the -NNN rotor were calculated and found to be consistent with a single minimum that corresponds to a gauche conformation (-NNN moiety nearly eclipses one of the two selenonyl Se=O bonds) for the three halogens at ambient temperature. The structural parameters for the minima calculated by MP2 and DFT turned out to be very similar. The vibrational modes, infrared and Raman intensities as well as depolarization ratios were calculated at DFT-B3LYP/6-311+G** level for the three molecules in their gauche conformations. The potential energy distributions among symmetry coordinates of the normal modes of the molecules in their gauche conformation were then computed from normal coordinate analyses.

Highlights

The conformational behavior of fluorosulfonyl isocyanate F-SO2-NCO and chlorosulfonyl isocyanate Cl-SO2-NCO has drawn the attention of structural chemists and spectroscopists because of their interesting structure and importance in chemistry [1,2,3,4,5,6]
In a previous study [13], we investigated the structural stability of the corresponding azides X-SO2-NNN (X is fluoride and chloride) for the purpose of comparison
The assignments of the vibrational modes were made based on calculated potential energy distributions (PED) values and experimental data reported for similar molecules [5,6]

Summary

Introduction

The conformational behavior of fluorosulfonyl isocyanate F-SO2-NCO and chlorosulfonyl isocyanate Cl-SO2-NCO has drawn the attention of structural chemists and spectroscopists because of their interesting structure and importance in chemistry [1,2,3,4,5,6]. Vibrational modes were calculated and normal coordinate calculations were carried out to compute the potential energy distributions (PED) among symmetry coordinates of all normal modes for the two molecules in their stable gauche conformation.

Results

Conclusion