Intermediates in the γ-radiolysis of diraient sulfur compounds in dilute glass matrices

Abstract

Can. J. Chem. 56, 1856(1978).The optical spectra of the charged ions obtained from y-irradiation of dilute alkyl niercaptans, sulfides, and disulfides in a variety of dilute rigid glasses are measured at 77 K. The photochemical stability of these ions is determined. A new photochromic species has been found. It is derived from a niercaptan dimer cation and is analogous to the photochromic anion produced from alkyl disulfides. The results of y-radiation are compared to the uv photolysis of similar matrices, and it is found that the thiyl (RS.) and perthiyl radicals (RS,.) are not generally in evidence in y-irradiated matrices although they may be obtained by appropriate annealing or photobleaching of the irradiated matrix. The ions which have been characterized optically are RSH+, RSH-, RSSR+ or their dimers, and RSS(H)R. The relative stabilities of these species in the low temperature glasses are determined.FRANK CUTHBERT ADAM, GLENN EDWARD SMITH et ALLEN JOHN ELLIOTT. Can. J. Chem. 56, 1856(1978).On a obtenu les spectres optiques d'ions portant des charges; ceux-ci ont ete prepares par irradiation y d'alkyl-niercaptans, de sulfures d'alkyle, de disulfures d'alkyle diluts dans un certain nombre de verres rigides a 77 K . On a determint la stabilite photochimique de ces ions. On a trouve une nouvelle espece photochromique. Elle derive d'un cation dimere du mercaptan et elle est analogue a I'anion photochromique obtenu a partir des disulfures d'alkyle. On a compare les rtsultats obtenus par irradiation y a ceux obtenus par photolyse uv de matrices semblables et on a trouve que les radicaux thiyl (RS.) et perthiyl (RS,.) lie se retrouvent geniralement pas dans les matrices ayant subit une irradiation y quoiqu'elles peuvent &tre obtenues si I'on recuit ou si I'on fait subir une photodecoloration appropriee a la matrice irradite. Les ions que I'on a caracterises d'une f a~o n optique sont RSH+, RSH-, RSSR+ ou leurs dimeres ainsi que RSS(H)R. On a determine les stabilites relatives d e ces especes dans des verres a basse temperature.[Traduit par le journal]

Ultrafast Formation of a Three-Electron-Bonded Radical Anion (CH3S∴SCH3-) in a Liquid Organic Sulfur Compound

“…Research works are mainly devoted to the stabilization of charged sulfides in dilute glass matrixes, the creation of Rydberg series, and state-selected ions in the gas phase by resonantly enhanced multiphoton ionization. [4][5][6][7][8] Photoexcited organic sulfides undergo different responses which can lead to bond scissions or ionization channels. The primary processes triggered by a UV excitation of liquid organic sulfides correspond to S-S or C-S bond scissions and yield multiple radicals such as methyl thiyl radical (CH 3 S • (A)) or thioformaldehyde (CH 2 S • (X)).…”

“…Charge-transfer processes involving organic sulfur compounds are of particular interest in biology and chemistry because transient sulfide radical ions can alter or protect the functional properties of enzymatic complexes or proteins. − During the past decade, the photochemistry of sulfur-containing molecules has received considerable attention. Research works are mainly devoted to the stabilization of charged sulfides in dilute glass matrixes, the creation of Rydberg series, and state-selected ions in the gas phase by resonantly enhanced multiphoton ionization. − Photoexcited organic sulfides undergo different responses which can lead to bond scissions or ionization channels. The primary processes triggered by a UV excitation of liquid organic sulfides correspond to S−S or C−S bond scissions and yield multiple radicals such as methyl thiyl radical (CH 3 S • (A)) or thioformaldehyde (CH 2 S • (X)). − These bond breakings can compete with ultrafast electron photodetachment processes.…”

UV Photolysis of C2H5SH in Solid CO and Ar

“…Following 254 nm photolysis of matrix isolated C 2 H 5 SH in xenon at 77 K, Skleton and Adam detected thiyl radical, ethylthiyl radical (C 2 H 5 S) using electron paramagnetic resonance. Adam et al later observed the same product after photolysis of C 2 H 5 SH in various dilute glass matrices. Bhuin et al measured the VUV spectrum of solid C 2 H 5 SH.…”

“…Detailed discussions of the assignments and identifications are in the Supporting Information. Generally, assignments were made possible by virtue of earlier spectroscopic measurements in both cryogenic matrices and the gas phase. ,,,− …”