Incoherent scattered radiation in diatomic molecules
Raman spectra excited in diatomic gases by the line λ2536 of mercury have been photographed with a quartz spectrograph. An apparatus for using gases at pressures from ten to fifteen atmospheres has been built, with great improvement as compared with the use of gases at atmospheric pressure. Results obtained with H2, N2, O2, NO are reported. A particularly complete investigation has been made of the hydrogen spectrum, leading to an accurate determination of the constants of the molecule in the normal electronic state. The numerical values are (in cm-1) B0=h/8π2I0c=59.40; ω0/1=4162.1. For N2, the corresponding values resulted to be: B0=1.992; ω0/1=2330.7. For O2: B0=1.436; ω0/1=1554.7. All these molecules are in Σ states, and the Raman spectra consist of Q-, double R-, and double P- form branches, as deduced from the Kramers-Heisenberg formula by the author and by Hill and Kemble. Nitric oxide is the only molecule so far investigated which is in a 2II state. The transition between the two terms of the doublet has been observed in the scattered radiation.
©1929 The American Physical Society. Received 15 June 1929. In conclusion, I wish to express my thanks to Professor R. A. Millikan for the facilities of the Norman Bridge Laboratory placed at my disposal; and to the International Education Board, to whose grant of fellowship my visit to America was due.