Rare Example of a Monomeric Aryllithium Complex. X-ray Crystal Structure of (2,4,6-Triphenylphenyl)lithium-Bis(diethyl ether)

Lithiation of 1-bromo-2,4,6-triphenylbenzene with n-butyllithium in diethyl ether gives (2,4,6-triphenylphenyl) lithium-bis(diethyl ether), whose X-ray crystal structure has been determined. This compound is a rare example of a monomeric organolithium reagent: the lithium atom adopts a planar three-coordinate geometry defined by the ipso carbon of the 2,4,6-triphenylphenyl group and two oxygen atoms of the diethyl ether solvate molecules; U-C = 2.08 (2) Å, Li-O = 1.93 (1) Å, O-Li-C = 124.0 (4)°, O-Li-O = 112.0 (8)°. Crystal data for LiC₃₂H₃₇O₂ at 26 °C: monoclinic, space group I2/a, with a = 11.732 (7) Å, b = 20.538 (13) Å, c = 11.723 (9) Å, β = 95.06 (6)°, V = 2814 (3) ų, Z = 4, R_F = 0.067, R_wF = 0.064 for 153 variables and 783 observed reflections.