Experimental and theoretical characterization of molecular complexes formed between OCS and XY molecules (X, Y - F, Gl and Br) and their role in photochemical matrix reactions

摘要

Molecular complexes between OCS and C1F, Cl2, Br2, or BrCl have for the first time been isolated in solid matrixes at low temperature, and characterized by their IR spectra. 1:1 adducts between OCS and C1F, Cl2, or BrCl were formed by broad-band UV-visible photolysis of matrix-isolated FC(0)SC1, C1C(0)SC1 or BrC(0)SCl, respectively. Co-deposition of gaseous mixtures of OCS and C1F or Br2 diluted with Ar on a Csl window cooled to approximately 15 K led to the identification of 1:1 complexes, while similar mixtures of OCS and Cl2 gave rise mainly to 1:2 species. The differences in the structures and stoichiometrics of the molecular complexes may well be responsible for the different reaction channels observed for the photochemical matrix reactions between OCS and Cl2 or Br2. The structures, energy differences, vibrational spectra, and bonding properties of all the possible complexes formed between OCS and XY (XY = C1F, Cl2, Br2, or BrCl) have been studied with different theoretical approximations.