High-resolution FIR spectrum of anti-vinyl alcohol

The {nu}_15_ OH torsional fundamental investigated here is more than 200cm^-1^ removed from the next nearest vibration, making it practically unperturbed and ideal to help refine the ground state rotational constants that were previously determined from 25 microwave lines.

We assigned 1335 lines within the {nu}_15_ fundamental centered at 261.5512cm^-1^, with J and K_a_ ranges of 1-59 and 0-16, respectively. The microwave and far-infrared line positions were fit with Watson-type A- and S-reduced Hamiltonians, with the inclusion of quartic and select sextic distortion terms. This resulted in a significant refinement of the ground state constants, in addition to the determination of the {nu}_15_=1 state constants for the first time.