Diminished cage effect in solid p-H2: Infrared absorption of CH3S observed from photolysis in situ of CH3SH, CH3SCH3, or CH3SSCH3 isolated in p-H2 matrices

Abstract

We report the infrared absorption spectrum of the methylthio (or thiomethoxy) radical, CH(3)S (X (2)E(3/2)), produced via photodissociation in situ of three precursors CH(3)SH, CH(3)SCH(3), and CH(3)SSCH(3) isolated in solid p-H(2). The common absorption features observed with similar intensity ratios in each experiment are assigned to CH(3)S. The wavenumbers of these features agree satisfactorily with those predicted with a spin-vibronic Hamiltonian accounting for the anharmonic effects and the Jahn-Teller effects to the quartic term [A. V. Marenich and J. E. Boggs, J. Chem. Theory Comput. 1, 1162 (2005)]. In addition to an absorption line at 724.2 cm(-1), corresponding to a transition of 3(1) previously determined to be 727 cm(-1) from fluorescence spectra of gaseous CH(3)S, we identified fundamental transitions 6(1)(a(1)) at 771.1, 6(1)(e) at 1056.6, 5(1)(a(1)) at 1400.0, 4(1)(a(1)) at 2898.4 cm(-1), and several combination and overtone transitions. In contrast, photolysis of CH(3)SSCH(3) isolated in solid Ar produces mainly H(2)CS, CH(3)SH, and CS(2), but no CH(3)S. These results demonstrate the feasibility of using photolysis in situ of precursors isolated in solid p-H(2) to produce free radicals by taking advantage of the diminished cage effect of the matrix.

Facile Synthesis of [Cu(SCH3)]∞ Nanowires with High Charge Mobility

“…The three absorption peaks at 2817, 2911, and 2978 cm À1 are attributed to the stretching modes of the ÀCH 3 group in the [Cu(SCH 3 )] 1 nanowires. [7] The peak at 1414 cm À1 is due to antisymmetric methyl deformation, [8] and the strong peak at 934 cm À1 is from the H-C-S bending. [9] The stretching frequency for the CÀS bond was observed at 681 cm À1 .…”

Infrared absorption of CH3SO2 observed upon irradiation of a p-H2 matrix containing CH3I and SO2

“…They are consistent with values of ν 3 , 2ν 4 , and ν 4 modes of CH 3 in p-H 2 reported previously. 31,34 After irradiation at 254 nm for 6.5 h, weak lines of CH 4 at 3026.0/3025.2 and 1308.3/1308.2 cm −1 appear. Annealing of the matrix at 4.7 K for 2 min after the irradiation showed intense lines due to C 2 H 6 , indicating that CH 3 is produced upon photolysis and might diffuse in solid p-H 2 at 4.7 K. Momose et al also observed CH 4 and C 2 H 6 upon irradiation of CH 3 I at 184.9 nm for 2.5 h in a p-H 2 matrix.…”

Infrared absorption of 3-propenonyl (⋅CH2CHCO) radical generated upon photolysis of acryloyl chloride [CH2CHC(O)Cl] in solid para-H2

“…The quantum solid para-hydrogen (p-H 2 ) has a diminished cage effect that allows the production of free radicals via photofragmentation [23][24][25] in situ or bimolecular reactions induced on irradiation. [26][27][28][29][30] In this work, we have photolyzed a CH 2 CHC(O)Cl/p-H 2 matrix at 3.2 K with laser light at 193 nm and observed absorption lines ascribable to 11 fundamental vibrational modes of 3-propenonyl (·CH 2 CHCO) radical.…”