Pure rotational Raman spectra of 16O2, 16O18O and 18O2

Abstract

The pure rotational Raman spectra of ¹⁶O₂, ¹⁶O¹⁸O and ¹⁸O₂ have been recorded and analysed, the latter two for the first time. The following rotational constants and bond lengths were determined: ¹⁶O₂ : B₀= 1.437 685 ± 0.000 05 cm^–1; 10⁶D₀= 4.61 ± 0.09 cm^–1; B_e= 1.445 8 ± 0.000 3 cm^–1; r₀= 1.210 85 ± 0.000 03 Å; r_e= 1.207 4 ± 0.000 2 Å. ¹⁶O¹⁸O : B₀= 1.357 81 ± 0.000 08 cm^–1; 10⁶D₀= 4.7 ± 0.2; B_e= 1.365 3 ± 0.000 3 cm^–1; r₀= 1.210 77 ± 0.000 06 Å; r_e= 1.2075 ± 0.000 2 Å. ¹⁸O₂ : B₀= 1.278 03 ± 0.000 05 cm^–1; 10⁶D₀= 3.84 ± 0.05; B_e= 1.284 7 ± 0.000 3 cm^–1; r₀= 1.210 64 ± 0.000 04 Å; r_e= 1.207 5 ± 0.000 1 Å.

These r₀ and r_e values agree with the bond lengths determined by microwave spectroscopy to within one standard deviation of error.