Preparation and characterization of cyclic polyolefin copper(I) trifluoroacetate complexes

Abstract

A series of polyolefin copper(I) trifluoroacetate complexes has been prepared with the following empirical formulae: Cu(O 2CCF 3)((Z.E.E)-1,5,9-cyclododecatriene): Cu(O 2CCF 3)(endo-dicyclopentadiene): Cu(O 2CCF 3) (1,5-cyclooctadiene); Cu 2(O 2CCF 3) 2(1,5-cyclooctadiene): Cu 2(O 2CCF 3) 2(1,3,5,7-cyclooctatetraene): Cu 4(O 2CCF 3) 4(1,3,5,7-cyclooctatetraene); and Cu 3(O 2CCF 3) 3(1,3,5-cycloheptatriene). These complexes are soluble in polar organic solvents and have been characterized in solution by 1H and 13C NMR and molecular weight studies. Although the polyolefins are labile in solution, the NMR studies have shown which double bonds are coordinated to copper for the olefins with non-equivalent double bonds and how many of the equivalent double bonds are coordinated for the more symmetric olefins. In all cases only one double bond is bound to each copper. For all of the complexes studied, the molecular weights are highly concentration dependent. increasing at higher concentrations. For the cyclododecatriene complex. the molecular weight levels at 660 in benzene, the molecular weight corresponding to a dimer. Similarly, the Cu 2(O 2CCF 3) 2(1,3,5,7-cyclooctatetraene) complex levels of at a dimer at high concentration in THF. The other complexes which are less soluble show molecular weights between that of a monomer and dimer.