Synthesis and Characterization of (THF)3Li(NC)CU(C6H3-2,6-Mes2)and Br(THF)2Mg(C6H3-2,6-Trip2) (Mes = C6H2-2,4,6-Me3; Trip = C6H2-2,4,6-i-Pr3): The Structures of a Monomeric Lower-Order Lithi

Abstract

The lower-order lithium organocyanocuprate compound, (THF) 3 Li(NC)Cu(C 6 H 3 -2,6-Mes 2 ) (1), and the bulky terphenyl Grignard reagent, Br(THF) 2 Mg(C 6 H 3 -2,6-Trip 2 ) (2), have been synthesized and structurally characterized both in the solid state by single crystal x-ray crystallography and in solution by multi-nuclear NMR and IR spectroscopy. The compound (1) was isolated as a monomeric contact ion-pair in which the C (organic ipso)-Cu-CN-Li atoms are coordinated linearly. The lithium has a tetrahedral geometry as a result of solvation by three THF molecules. The compound (1) is the first example of fully characterized monomeric lower order lithium organocyanocuprate. The bulky Grignard reagent (2) was also isolated as a monomer in which the magnesium, solvated by two THF molecules, has a distorted tetrahedral geometry. The crystals of (1) possess triclinic symmetry with the space group P1, Z = 2, with a = 12.456(3) A, b = 12.508(3) A, c = 13.904(3) A, α = 99.81°, β = 103.72(3)°, and y= 119.44(3)°. The crystals (2) have a monoclinic symmetry of space group P2 1 /c, Z = 4, with a = 13.071(3) A, b = 14.967(3) A, c = 22.070(4) A, and β = 98.95(3)°.