Millimeter and Submillimeter Wave Spectrum and Molecular Constants of Aluminum Monofluoride

Rotational transitions of 27Al19F have been measured in the millimeter and submillimeter wave regions to frequencies of 461 Gc/sec. Vibrational states up to υ = 4 were observed. From analysis of the data the following Dunham rotational constants were obtained: Y01 = 16 562.930 ± 0.006 Mc/sec, Y11 = − 149.420 ± 0.009 Mc/sec, Y21 = 0.515 ± 0.004 Mc/sec, Y31 = 1.4 ± 0.6 kc/sec, Y02 = − 31.37 ± 0.02 kc/sec, and Y12 = 0.046 ± 0.014 kc/sec. The Dunham potential constants found are: a0 = 2.9167 ± 0.0019 × 105, a1 = − 3.1850 ± 0.0009, a2 = 6.82 ± 0.06, and a3 = − 11.6 ± 0.6 cm−1. The nuclear quadrupole coupling constants obtained are: eqQ(27Al) = − 37.59 ± 0.25 Mc/sec for υ = 0 and eqQ(27Al) = − 37.14 ± 0.6 Mc/sec for the υ = 1 vibrational state. Vibrational constants derived are ωe = 802.85 ± 0.25 cm−1 and ωexe = 4.86 ± 0.06 cm−1. The equilibrium internuclear distance re = 1.65436 ± 0.00002 Å was obtained.