136448-74-3Relevant articles and documents
Exchange processes in diselenium and selenium-sulfur dihalides, Se2X2 and SeSX2 (X = Br, Cl). A 77Se 2D-EXSY study
Milne, John,Williams, Antony J.
, p. 4534 - 4538 (2008/10/08)
The application of two-dimensional NMR exchange spectroscopy (2D-EXSY) to the study of 77Se exchange kinetics in mixtures of S2Cl2 and Se2Br2, which contain disulfur, diselenium, and selenium sulfur dihalides, shows that 77Se magnetization transfer takes place predominantly by an exchange process, in which only SeX bonds are broken. Direct exchange via mechanisms, involving ChX radicals, four-chalcogen center transition states and mono- and trichalcogen dihalide species are not consistent with the cross peaks observed in the 2D spectra. Magnetization transfer by means of a bimolecular halogen-bridged intermediate (Chemical Equation Presented) or by an ionic process, involving Se-X bonds, are both consistent with the pattern of cross observed. However, the addition of tetraethylammonium chloride to the S2Cl2/Se2Br2 mixture causes the eight-signal spectrum to collapse to three broad signals, which favors an interpretation in terms of an ionic exchange mechanism. The three broad signals are assigned to BrSSeX, ClSSeX, and SeSe dihalides each undergoing rapid ionic exchange, involving SeX bonds.
Selenium sulfur dihalides, ChnX2 (n = 1, 2, 3; Ch = Se, S; X = Br, Cl). Raman and 77Se NMR spectroscopic characterization
Milne, John B.
, p. 693 - 699 (2007/10/02)
Solutions of Se2Cl2 in S2Cl2, Se2Br2 in S2Cl2, Se in S2Cl2, and S in Se2Cl2 have been studied by Raman and 77Se NMR spectroscopy.Selenium sulfur dihalides, SeSCl2, SeSBr2, and SeSBrCl, formed in these solutions, have been shown by Raman and 77Se NMR spectroscopy to have chain structures.Solutions of Se2Cl2 in S2Cl2, S in Se2Cl2, and Se in S2Cl2 have been shown to contain, in addition to Se2Cl2, S2Cl2, SeSCl2, Se3Cl2, and S8, trichalcogen dichlorides Se2SCl2 and SeS2Cl2.Selenium-77 signals corresponding to all seven chain isomers of the expected Se-containing dichalcogen dihalides, Se2Br2, Se2Cl2, Se2BrCl, SeSCl2, SeSBr2, BrSeSCl, and ClSeSBr, have been observed in the spectrum of a 1:1 molar mixture of S2Cl2 and Se2Br2.The disulfur dichloride and dibromide, as well as the bromide chloride, are also present.Selenium-bromine and sulfur-chlorine linkages are observed to be preferred over selenium-chlorine and sulfur-bromine bonding in these mixtures.The 77Se chemical shifts correlate well with the electronegativity of the directly bonded neighbour but inversely with that of the next-nearest neighbour.Key words: selenium halides, sulfur halides, low valent chalcogen halides, 77Se NMR, Raman spectroscopy.
