Lewis-Base Adducts of Main Group-1 Metal-Compounds. IX. Synthesis and Structural Characterization of Adducts of the Lithium(1) Halides With N,N,N',N'-Tetramethylethylenediamine

Abstract

Crystalline adducts of the lithium(I) halides, LiX (X = Cl , Br, I) with N,N,N′,N′- tetramethylethyl-enediamine (tmeda) have been synthesized and characterized by single-crystal X-ray studies. Both bromide and iodide form 1 : 1 adducts which are μ,μ-dihalo-bridged binuclear species, [( tmeda )LiX₂Li( tmeda )], with four-coordinate N₂LiX₂ lithium environments; in addition, the iodide yields an ionic 1 : 2 adduct, [Li( tmeda )2]⁺I^-. The chloride complex is a novel 3 : 2 polymer based an a double cubane Li₆Cl₆ unit solvated by chelating and bridging tmeda units.