Abstract

Resonance two-photon ionization (R2PI) spectroscopy has been used for medium resolution studies of HCO and DCO. Vibronic analysis of subband positions for both A′ and A″ symmetry components of the 3p²Π Rydberg states of HCO and DCO yields values for the Renner-Teller parameter ε, dipolar coupling constant g_k, quartic anharmonicity parameter g₂₂, harmonic bending vibrational frequency ω₂, anharmonicity constant x₂₂, and spin-orbit splitting constant A. Values of the harmonic frequencies (ω₂ and anharmonicity constants x₂₂ for the bending vibrations of the HCO and DCO ${\tilde{\chi }}^2{A}^{\prime }$ ground states are also determined. Term values, the three harmonic vibrational frequencies, and six anharmonicity constants are measured for the ${\tilde{\text{B}}}^2{A}^{\prime }$ states of both molecules. Fundamental frequencies of 1382 cm⁻¹ and 1213 cm⁻¹ for HCO and DCO, respectively, are identified with the $\tilde{\text{B}}$ state bending vibration; frequencies of 2597 cm⁻¹ for HCO and 1944 cm⁻¹ for DCO correspond to CH (CD) stretching, while the lowest fundamental frequencies of 1066 cm⁻¹ for HCO and 922 cm⁻¹ for DCO correspond to the vibration of singly bonded C-O.

© 1992 Optical Society of America