47690-18-6Relevant articles and documents
Two isomers of WCl3(PMe2Ph)3 and their potential for equilibration with W2Cl6(PMe2Ph)n
Rothfuss, Helmut,Barry, Jane T.,Huffman, John C.,Caulton, Kenneth G.,Chisholm, Malcolm H.
, p. 4573 - 4577 (2008/10/08)
A new (comproportionation) synthesis of WCl3(PMe2Ph)3, as well as the coexistence of two structural isomers, is reported. These are characterized by 1H NMR spectroscopy and single-crystal X-ray diffraction. Equilibration of these two species is effected at 80°C, with mer converting completely to fac. It is not possible to convert the WCl3L3 (L = PMe2Ph) species to either of the known dimers W2Cl6Ln, (n = 3, 4). The mer → fac isomerization is shown to be catalyzed by WCl4L2 (but not by WCl2L4). The mechanism of the comproportionation synthesis of WCl3L3 strongly favors the mer isomer, and a mechanism is proposed to account for this. Photolysis of a mixture of [WCl3(PMe2Ph)2]2 in the presence of excess PMe2Ph completely converts the dimer to mer-WCl3(PMe2Ph)3. Mechanistic features which cause the stereoselectivity of this reaction are discussed. Cell parameters for fac-WCl3L3 (-165°C): a = 9.476(2) A?, b = 18.091 (5) A?, c = 9.185(2) A?, α = 98.62(1)°, β = 101.53(1)°, γ = 93.49(1)° with Z = 2 in space group P1. Cell parameters for mer WCl3L3 at -155°C, a = 16.031(3) A?, b = 10.297(1) A?, c = 17.913(3), β = 113.86(1)°, Z = 4, and space group P21/c.
