Absolute photodissociation cross sections of gas phase sodium chloride at room temperature

Absolute photodissociation cross sections for gas phase NaCl are measured over the wavelength range of 189.7–359.8 nm at 300 K. Two well-resolved peaks are observed at 235 and 260 nm. The cross section also rises below 210 nm. These results are in good qualitative agreement with previous high temperature measurements and with cross sections computed from theoretically calculated potential surfaces. However, there are two significant differences, the spectral width and the absolute magnitude of the cross sections. The importance of these measurements in understanding the photodissociative processes of ionic compounds and the implications for the role of NaCl in the stratospheric chemistry of chlorine compounds are discussed.