Experimental and Theoretical Characterization of Molecular Complexes Formed between OCS and XY Molecules (X, Y = F, Cl and Br) and their Role in Photochemical Matrix Reactions

A. LORENA PICONE; CARLOS O. DELLA VÉDOVA; HELGE WILLNER; ANTHONY J. DOWNS; ROSANA M. ROMANO

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Año: 2010 vol. 12 p. 563 - 571

1463-9076

Molecular complexes between OCS and ClF, 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 ClF, Cl2, or BrCl were formed by broad-band UV-visible photolysis of matrix-isolated FC(O)SCl, ClC(O)SCl, or BrC(O)SCl, respectively. Co-deposition of gaseous mixtures of OCS and ClF or Br2 diluted with Ar on a CsI 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 stoichiometries 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 = ClF, Cl2, Br2, or BrCl) have been studied with different theoretical approximations.