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

Abstract

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.

Synthesis and properties of N3 and CN delivery compounds and related precursors for nitride and ceramic fabrication

“…The As-X bond lengths (X = H,Cl,Br) are found to exhibit the largest systematic increases with b(As-H) ≈ 1.534 Å, b(As-Cl) ≈ 2.208 Å and b(As-Br) 2.379 Å. This is virtually identical to the behavior in haloselenonyl azides, [14] where b(Se-Cl) ≈ 2.223 Å and b(Se-Br) ≈ 2.387 Å are predicted using a very similar level of theory. The calculated bond angles also exhibit well-defined trends.…”

“…The present calculations were carried out using the Gaussian03 code at the 6-311G++(3df,3pd) level. www.interscience.wiley.com/journal/aoc Prior work on haloselenonyl azides XSeO 2 -N 3 (X = F, Cl, Br) [14] using DFT B3LYP calculations and a smaller 6-311+G * basis set than that used here yielded structural and vibrational properties very similar to those obtained from a much more computationally demanding MP2 ab initio treatment of electron correlation effects. We therefore expect our present approach using a much more expanded basis set than 6-311+G * to provide a very quantitative description of the molecular properties.…”