Synthesis and properties of a new ketoiminate derivative of the 2,2,6,6-tetramethylheptane-3,5-dionate ligand to prepare volatile CVD precursors

The beta-ketoimine (CH3)(3)CC(NH2)CHC(O)C(CH3)(3) (1) was synthesized by amination with dry ammonia in the presence of TiCl4. M.p. = 131 degrees C. IR and H-1 and C-13 NMR spectroscopic characterization indicates that the structure of a solution of 1 is the ketone form, and a single-crystal X-ray diffraction study shows that the structure of I is the enaminoketone form. The reaction of I with copper(II) and nickel(II) salts in solution gave chelate metal complexes: Cu[(CH3)(3)CC(NH)CHC(O)C(CH3)(3)](2) (2), M.p. = 209 degrees C, and Ni[(CH3)(3)CC(NH)CHC(O)C(CH3)(3)](2) (3), M.p. = 267 degrees C. These complexes are volatile and sublime at 180-190 degrees C at 5 x 10(-3) Torr. An X-ray diffraction study reveals that these metal complexes are monomeric and isostructural in the solid state. In compound 2, the Cu atom has a square coordination environment: Cu-OZ approximate to Cu-N = 1.91 angstrom, angle O-Cu-N = 91.81 angstrom. (c) 2007 Elsevier Ltd. All rights reserved.