Die ir- und raman-spektren des dithioessigsäure-methylesters und des dimethyltrithiocarbonats

Formation of New Halogenothiocarbonylsulfenyl Halides, XC(S)SY, through Photochemical Matrix Reactions Starting from CS2and a Dihalogen Molecule XY (XY = Cl2, Br2, or BrCl)

Isolation of a dihalogen molecule XY (XY=Cl2, Br2, or BrCl) with CS2 in a solid Ar matrix at about 15 K leads, by broad-band UV-vis photolysis (200<or=lambda<or=800 nm), to a variety of products depending on the natures of X and Y. These products have been identified on the basis of the IR spectra of the matrices. In addition to the familiar species SCCl2, ClCS*, Cl*...SCS, CCl4, *CCl3, :CCl2, SCl2, SCBr2, CBr4, *CBr3, BrC(S)Cl, BrCCl3, and :CBrCl, the following new molecules have also been identified as products of the various photoreactions: syn-ClC(S)SCl, anti-ClC(S)SCl, syn-BrC(S)SBr, anti-BrC(S)SBr, syn-ClC(S)SBr, anti-ClC(S)SBr, syn-BrC(S)SCl, anti-BrC(S)SCl, ClC(S)S*, BrCS*, and Br*...SCS. The IR spectra of these hitherto unknown species have been interpreted with reference to the predictions of ab initio (HF and MP2) and density functional theory (DFT) calculations. The results are analyzed in relation to the reaction pathways accessed by matrix photolysis.