15min:

BLAKE A. MCELMURRY, JOHN W. BEVAN, ROBERT R. LUCCHESE, Department of Chemistry, Texas A&M University, College Station, TX 77843-3255; IGOR I. LEONOV, Institute of Applied Physics of Russia Academy of Sciences, Uljanova Str. 46, Nizhny Novgorod 603600, Russia.

The lowest frequency bending vibrations of Ar-H⁷⁹Br and Ar-H⁸¹Br have been recorded using TAMU fast scan BWO spectrometer with co-axial supersonic jet expansion. The fitted band origin was ₀ = 329611.4482(16) MHz, the excited state rotational constant was B = 1236.41359(22) MHz, the distortion constants were D_J = 0.0124740(36) MHz and H_J = -2.503(17) × 10^-6 MHz and the quadrupole constants were _aa = 260.9552(79) MHz and D_ _aa = -0.03174(35) MHz for Ar-H⁷⁹Br. The corresponding constants for Ar-H⁸¹Br were: ₀ = 329225.6995(15) MHz, B = 1226.77332(22) MHz, D_J = 0.0123085(37) MHz, H_J = -2.459(19)× 10^-6 MHz, _aa = 217.8952(75) MHz, and D_ _aa = -0.02619(36) MHz. The values of _aa and D_ _aa can be compared with the corresponding values predicted from a recently modeled complete vibrationally morphed potential of Ar-HBr and used for further optimization of that potential.