Infrared Spectrum of N15O2 and Force Constants of NO2

Abstract

The infrared spectrum of N¹⁵O₂ has been investigated and the following frequencies were determined: $${\nu }_1{\mathrm{(a}}_1\text{)=1312±3\hspace{0.17em}}{\mathrm{cm}}^{\text{−1}}{\mathrm{,\hspace{0.17em}\hspace{0.17em}\nu }}_2{\mathrm{(a}}_1\text{)=739.7±0.5\hspace{0.17em}}{\mathrm{cm}}^{\text{−1}}{\mathrm{,\hspace{0.17em}\hspace{0.17em}\nu }}_3{\mathrm{(b}}_1\text{)=1578±2\hspace{0.17em}}{\mathrm{cm}}^{\text{−1}}.$$ From these and the frequencies for N¹⁴O₂, the following force constants were obtained: f_d=10.4±0.5, fα/d²=1.29±0.08, f_dd=1.45±0.50, f_dα/d=0.098±0.180 (all in millidynes/A).