FUNCTIONALIZED ALKYNE COMPLEXES OF TUNGSTEN(VI) - SYNTHESES AND CRYSTAL STRUCTURES OF [WCL4(ET-SE-C-C-SE-ET)(THF)] AND [WCL4(ET-TE-C-C-TE-ET)(THF)] [German]

摘要

The title compounds have been prepared by reactions of [WCl4(SEt(2))(2)] with the alkynes Et-X-C=C-X-Et (X = Se, Te) in CCl4 solution and subsequent addition of tetrahydrofurane. Both complexes were characterized by crystal structure determinations. [WCl4(Et-Se-C=C-Se-Et)(THF)]: Space group P2(1), Z = 4, structure determination with 2942 unique reflections, R = 0.038. Lattice dimensions at 20 degrees C: a = 934.2, b = 1639.5, c = 1189.5 pm, beta = 96.497 degrees. [WCl4(Et-Te-C=C-Te-Et)(THF)]: Space group P2(1), Z = 4, structure determination with 4097 unique reflections, R = 0.067. Lattice dimensions at -70 degrees C: a = 899.2, b = 1691.9, c = 1213.3 pm, beta = 96.82 degrees. The complexes have monomeric molecular structures with the oxygen atom of the THF molecules in trans-position to the side-on bound alkyne ligands. [References: 20]