Photolysis of in frozen Nujol Matrices

Article abstract of DOI:10.1016/S0022-328X(98)00512-9

A series of compounds, (η⁵-C5H4C4H9)2Mo2(CO)4(μ-η^2:2-acetylene), where acetylene = 3-hexyne, diphenylacetylene, phenylacetylene and 1-phenylpropyne, was prepared and characterized by IR, 1H- and 13C-NMR spectroscopies and MS.Photolysis of these compounds was carried out in frozen Nujol at 77 K.IR spectra established the presence of two isomeric carbonyl-loss species, (η⁵-C5H4C4H9)2Mo2(CO)2(μ-η^2:2-acetylene), A, and (η⁵-C5H4C4H9)2Mo2(μ-CO)3(μ-η^2:2-acetylene), B.A is formed by photolysis into low energy electronic transitions associated with the tetrahedrane core of the parent molcule, while B is formed by either photolysis into electronic bands associated with A, or photolysis into the high energy charge-transfer bands of the parent molecule.These photointermediates are likely to be involved in the formation of 'fly-over' compounds, resulting from thermally or photochemically induced multiple substitution of acetylenes. - Keywords: Molybdenum; Carbonyls; Cyclopentadienyls; Photochemistry; Matrices