Photophysical effects on laser induced grating spectroscopy of toluene and acetone

► Molecular quenching dynamics are studied by laser induced grating spectroscopy. ► Concentration of oxygen strongly affects quenching rate for toluene and acetone. ► Modulation depth of signal depends on energy transfer rate to bulk gas. ► Pressure dependence of signal modulation is sensitive to molecular photophysics. ► Observations are explained by a model of photophysics and relaxation dynamics.