&mgr;-Benzene in a Heterobimetallic Fluoroalkoxide: CH.FC Hydrogen Bonding?
The syntheses of Lewis base-free [Pb(HFIP)(2)] (HFIP = OCH(CF(3))(2)) and [Li(HFIP)] are described. [Pb(OR)(2)] (OR = O(i)Pr or HFIP) reacts with [LiOR] to give [PbLi(OR)(3)](n)(), which sublimes intact at a temperature lower than the sublimation temperatures of its constituent alkoxides. By multinuclear solution NMR spectroscopy, evidence for more than one [PbLi(OR)(3)] oligomer is found. The HFIP heterobimetallic species crystallizes from benzene as a dimer (i.e., n = 2) with 1 equiv of C(6)H(6) in its lattice, while the nonfluorinated analog does not. The numerous CH.FC distances observed by a crystallographic study approach the sum of the van der Waals radii of H and F. Crystallographic data (P&onemacr; at -172 degrees C) for [Pb(2)Li(2)(HFIP)(6)(C(6)H(6))]: a = 10.020(4) Å, b = 12.367(5) Å, c = 9.784(4) Å, alpha = 106.03(2) degrees, beta = 107.72(2) degrees, and gamma = 105.36(2) degrees with Z = 1.
Teff
Daniel J.
DJ
Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405-4001.
Huffman
John C.
JC
Caulton
Kenneth G.
KG