Laser Stark and laser microwave double resonance spectroscopy of fluoroacetylene with the CO2 laser

The CO₂ laser Stark spectrum of fluoroacetylene was identified for the ν₃, ν₃ + ν₄ ? ν₄, and ν₃ + ν₅ ? ν₅ vibrational bands. The origins of these bands were precisely determined (±0.0003 cm^?1) to be 1061.4452, 1059.0639, and 1064.6960 cm^?1. A CO₂ laser microwave double resonance experiment in the presence of the Stark field is described. This technique was applied to assignment of the Stark spectrum, calibration of the Stark electrode spacing, and precise determination (±0.0003 D) of dipole moment. The dipole moments of the HCCF molecule in the ground, ν₃, ν₄, ν₅, ν₃ + ν₄, and ν₃ + ν₅ vibrational states are 0.7207, 0.7447, 0.6557, 0.7441, 0.6769, and 0.7689 D.