Structural and Energetic Features of Group 13 Element Trispentafluorophenyl Complexes with Diethyl Ether

The complexes of group 13 element trispentafluorophenyl derivatives E(C6F5)(3) (E = B, Al, Ga, In) with diethyl ether of 1:1 composition have been synthesized and structurally characterized. All compounds are isostructural. Thermal stability studies reveal that at elevated temperatures all complexes decompose with pentafluorobenzene evolution. The geometries and thermodynamic characteristics for the dissociation reactions of the compounds have been computed using three DFT methods. The H-1 NMR alpha-proton chemical shifts for the coordinated ether in deuteriobenzene and in CD2Cl2 solutions correlate with gas phase dissociation enthalpies of the complexes. Potentially high Lewis acidity of B(C6F5)(3) is hindered by the large pyramidalization energy of the acceptor moiety.