Isotopically selective dissociation of COCl/sub 2/ molecules in the radiation field of a pulsed CO laser
The first report is given of attainment of isotopically selective dissociation of carbonyl chloride COCl/sub 2/ molecules by radiation from a pulsed tunable uncooled electron-beam-controlled CO laser. Carbonyl chloride was labeled with /sup 13/C and /sup 18/O and the isotopic ratio was /sup 12/C/sup 16/OCl/sub 2/: /sup 13/C/sup 16/OCl/sub 2/:/sup 12/C/sup 18/OCl/sub 2/ = 1:1:0.1, which made it possible to observe simultaneously the selectivity in respect of carbon and oxygen in the product (CO). The dissociation was produced by laser pulses of 0.5--1 J energy (energy density approx.5 J/cm/sup 2/) and of approx.5 ..mu..sec duration at half-intensity. The dependences of the selectivity ..cap alpha.. and of the dissociation yield on the pressure of the substance was studied in the course of irradiation of COCl/sub 2/ at the frequency corresponding to the P/sub 10/(22) (..nu.. = 1822.0 cm/sup -1/) transition in the CO laser. The selectivity in respect of the carbon /sup 12/C and oxygen /sup 16/O was the same, and it fell on increase in the pressure p of COCl/sub 2/. The maximum value of ..cap alpha..roughly-equal4 was obtained at p = 0.5 Torr.