Thermoluminescence following vuv photolysis of OCS and CS2 in an argon matrix

Abstract

The vuv photodissociation of OCS in an argon matrix at 5 K has been shown to yield S(1S) atoms. The S(1S –1D) emission is observed only during the irradiation and does not appear when CS2 is photolyzed under the same conditions. However, in both cases the thermoluminescence which follows an increase of the matrix temperature is due to the S2(B 3Σu−→X 3Σg−) radiative transition. This substantiates the fact that S atoms do indeed diffuse in an argon matrix already at 6 K. Furthermore, the (a 3Π→X 1Σ+) emission of CS is observed both during the CS2 irradiation and as thermoluminescence. This last observation suggests that C atoms can also diffuse under these conditions at about the same rate as the diffusion rate of N atoms in N2 matrix, measured by Brocklehurst and Pimentel.

Low-temperature thermoluminescence in solid argon: Short-range mobility of atoms

“…2 In the thermally induced movement, atoms can reach each other and react, producing often in exothermic chemical reactions excited species that decay radiatively, and this effect is referred to as thermoluminescence or chemiluminescence. [3][4][5][6][7][8][9][10] The classical example of thermoluminescence is recombination of oxygen and sulfur atoms in various combinations, and the reactions of interest are…”

Direct Observation of the C + S2 Channel in CS2 Photodissociation

“…The VMI images can be used to determine the recoil velocity distribution of the C ( 3 P J ) photofragments from the radii of the resolved ring structures. The velocities are converted to a total kinetic energy release (TKER) spectrum of the C ( 3 P J ) + S 2 (X 3 Σ g – ) channel by using eq based on the conservation of linear momentum and energy Here, D 0 is the thermochemical threshold for the formation of the C ( 3 P J ) + S 2 (X 3 Σ g – ) products from CS 2 dissociation, which was determined to be 7.86 eV (157.7 nm) by Fournier et al However, our experiments have recorded the image of C ( 3 P 0 ) at the longest wavelength of ∼333 nm (Figure S1), suggesting the thermochemical threshold of C ( 3 P 0 ) + S 2 (X 3 Σ g – ) channel should be lower than 7.45 eV (166.5 nm). Figure displays the TKER distributions of the C ( 3 P 1 ) channel by integrating over all product angles.…”

“…Here, D 0 is the thermochemical threshold for the formation of the C ( 3 P J ) + S 2 (X 3 Σ g − ) products from CS 2 dissociation, which was determined to be 7.86 eV (157.7 nm) by Fournier et al 36 However, our experiments have recorded the image of C ( 3 P 0 ) at the longest wavelength of ∼333 nm (Figure S1), suggesting the thermochemical threshold of C ( 3 P 0 ) + S 2 (X 3 Σ g − ) channel should be lower than 7.45 eV (166.5 nm). channel by integrating over all product angles.…”

Snm as a Photolabile Protecting Group for the Cysteinyl Radical − Direct Evidence from Time‐Resolved IR and UV/Vis Spectroscopies

“…[18] Thus, we expect a similar rate constant for the loss of COS from radical 1. Within the time range of 20 µs, however, no COS signal (2049.5 cm Ϫ1 ) [19] was observed in the IR spectra. This observation might be explained by the slow hydrolysis of COS to CO 2 and H 2 S (at 25°C, the pseudo-first-order rate constant is 0.0011 s Ϫ1 ).…”