Comparative properties of fluorous phosphine ligand complexes: W(CO)5LF. Crystal structure of W(CO)5P(C6H4-4-CH2CH2(CF2)7CF3)3

The compounds W(CO)(5)P(C6H4-4-CH2CH2(CF2)(7)CF3)(3) (1) and W(CO)(5)P(CH2CH2(CF2)(5)CF3)(3) (2) were synthesized in order to probe the electronic and physical effects of ligation by perfluorocarbon substituted tertiary phosphine ligands in a W(CO)(5)L complex. The pi-accepting ability of the fluorous phosphines was found to rank with non-fluorous comparators as P(CH2CH2(CF2)(5)CF3)(3) > P(C6H4-4-CH2CH2(CF2)(7)CF3)(3) > PPh3 > P(p-tolyl)(3) > P(n-octyl)(3). The X-ray crystal structure of W(CO)(5)P(C6H4-4-CH2CH2(CF2)(7)CF3)(3) shows strong intermolecular association of fluorous components but confirms that the parafluorocarbon subtituents have an insignificant effect on the tungsten coordination environment. Partition coefficients (toluene/perfluoromethylcyclohexane) were measured for compounds 1 and 2. (C) 2009 Elsevier B.V. All rights reserved.