Dispersed fluorescence spectroscopy of formaldehyde in a free-jet expansion

CHED 1392

Kristin K. Ellsworth, Brian D. Lajiness, and William F. Polik. Department of Chemistry, Hope College, Holland, MI 49423
High resolution dispersed fluorescence (DF) spectra of the excited vibrational levels in formaldehyde (H2CO) have been recorded to describe its S0 potential energy surface. Formaldehyde was cooled in a free-jet expansion and excited with a laser to the 40, 41, 3141 and 51 levels in S1. The resulting fluorescence was dispersed with a monochrometer to yield S0 vibrational spectra. 235 vibrational levels have been assigned and fit to a polyad model. The model includes harmonic and anharmonic terms, and it also accounts for resonances among vibrational levels. DF spectra of the 40, 41 and 4161 levels in formaldehyde-d (HDCO) were also recorded, and the assignment of these spectra is in progress.