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Quantum yield for carbon monoxide production in the 248 nm photodissociation of carbonyl sulfide (OCS)
Author(s) -
Zhao Z.,
Stickel R. E.,
Wine P. H.
Publication year - 1995
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/95gl00170
Subject(s) - photodissociation , quantum yield , carbonyl sulfide , carbon monoxide , dissociation (chemistry) , photochemistry , chemistry , yield (engineering) , analytical chemistry (journal) , materials science , sulfur , optics , organic chemistry , fluorescence , physics , catalysis , metallurgy
Tunable diode laser absorption spectroscopy has been coupled with excimer laser flash photolysis to measure the quantum yield for CO production from 248 nm photo‐dissociation of carbonyl sulfide (OCS) relative to the well‐known quantum yield for CO production from 248 nm photolysis of phosgene (Cl 2 CO). The temporal resolution of the experiments was sufficient to distinguish CO formed directly by photodissociation from that formed by subsequent S(³P J ) reaction with OCS. Under the experimental conditions employed, CO formation via the fast S(¹D 2 ) + OCS reaction was minimal. Measurements at 297K and total pressures from 4 to 100 Torr N 2 + N 2 O show the CO yield to be greater than 0.95 and most likely unity. This result suggests that the contribution of OCS as a precursor to the lower stratospheric sulfate aerosol layer is somewhat larger than previously thought.