High‐resolution Fourier transform Raman spectra of the fundamental bands of 14N15N and 15N2

Abstract

AbstractThe Fourier transform Raman spectra of the fundamental bands of 14N15N and 15N2 were measured with a resolution of 0.02 cm−1. Lines from all branches (O, Q, S) were observed and measured. The analyses of the wavenumbers yield improved values for the band origins ν0(14N15N) = 2291.33773(8) cm−1 and ν0(15N2) = 2252.07846(9) cm−1 and improved values for the rotational parameters of the ground state and the first excited state of the two molecules. The values obtained for 14N15N are B0 = 1.9236102(35) cm−1 and D0 = 5.3530(94) × 10−6 cm−1 and B1 − B0 = −0.01651064(86) cm−1 and D1 − D0 = 1.06(16) × 10−8 cm−1. For 15N2 the following values obtained are B0 = 1.8576250(36) cm−1, D0 = 4.9760(87), B1 − B0 = 0.01566657(99) cm−1 and D1 − D0 = 0.94(18) × 10−8 cm−1. The bond length calculated for all three isotopomers of molecular nitrogen shows a systematic decrease with increasing molecular mass. Copyright © 2001 John Wiley & Sons, Ltd.