Figure 15.

Top: 2400–600 cm⁻¹ region of the difference IR spectrum: irradiated Ar matrix of 2-fluorobenzoic acid (2FBA) minus as-deposited matrix. Bottom: Simulated difference spectrum based on the B3LYP/6-311++G(d,p) calculated IR spectra of 2FBA (cis-I and cis-II conformers; bands pointing down) and the observed photoproducts: CO₂, CO, and fluorobenzene (FB) (bands pointing up). The calculated wavenumbers were scaled by 0.978, and the calculated intensities were multiplied by arbitrary factors in order to fit better the observed spectrum (in a ratio of ~2:1:3, 2FBA cis-II:2FBA cis-II:FB).