CYCLIC METAL(IV) AMIDES

Synthesis and structure of cyclic amide complexes of quadrivalent titanium, vanadium, and chromium are described, and their electrochemical behavior is investigated by cyclic voltammetry. The novel amides of formula ML2 {M = Ti, (3b); M = V, (3c); M = Cr, (3d); L = [(CH3)3SiNCH2CH2NSi(CH3)3]} are formed by reaction of the halide adducts MCl3(THF)3 with the dilithium salt Li2L with concomitant disproportionation. Formation of 3d proceeds via the complex [3 d]- and requires additional oxidation with oxygen or iodine. An X-ray crystal-structure determination of 3b reveals the titanium atom in strongly distorted tetrahedral environment with approximate symmetry D2d. The amide complexes 3b - d are monomeric, thermally stable, and sublime readily without decomposition; they are very sensitive to water and soluble in all common organic solvents.