Zeeman effect in the IR spectrum of a molecule without EN electronic moment. Observation with a tunable diode laser

The Zeeman effect in the infrared absorption spectrum of a molecule without an electronic magnetic moment was observed using a linear spectroscopic technique with a tunable diode laser. In the magnetic field B = 500 kG weak splittings of the asR(4, 1) and asR(4, 0) lines in the v 2 -band of NH 3 were recorded. The values of the Zeeman splittings in these cases were −1×10 -2 cm -1 . The picture of the Zeeman splittings observed is shown to be connected with the difference between the g -factors for the excited (υ 2 = 1) and the ground (υ 2 = 0) vibrational states of the NH 3 molecule. This difference is about (-10)-(15)% of the g -factor for the lower vibrational level of the transition.