The Preparation and Properties of Volatile Tris(‑Alkoxycarboxamidato)chromium(III) Complexes as Potential Single-Source Precursors for the MOCVD of Crystalline Chromium Oxide Thin Films.

The synthesis, characterization, and vapor-phase growth of volatile Cr-(III) complexes as single-source precursors for CrO thin films are reported. A series of Cr complexesCr-(mdpa) (mdpa = -methoxy-2,2-dimethylpropanamide) (), Cr-(edpa) (edpa = -ethoxy-2,2-dimethylpropanamide) (), Cr-(empa) (empa = -ethoxy-2-methylpropanamide) (), and Cr-(mpa) (mpa = -methoxypropanamide) ()were synthesized via salt elimination reactions between CrCl·3THF and -alkoxy carboxamidate salts. These complexes were characterized by Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis (TGA), single-crystal X-ray diffraction (SC-XRD), Hirshfeld surface analysis, powder X-ray diffraction (PXRD), and vapor pressure measurement. The crystal structure of complex revealed a distorted octahedral geometry with a κ (O,O) binding mode. TGA demonstrated that complex underwent weight loss at 132 °C and no residue remained at 500 °C. The enthalpy of vaporization of was estimated to be 25.58 kJ/mol, making it an optimal precursor for CrO thin films. The XRD patterns of CrO films deposited on SiO/Si substrates confirmed their crystalline nature, showing prominent peaks at 2θ = 33.5° and 41.5°. In addition, X-ray photoelectron spectroscopy validated the target Cr/O ratio, supporting the successful formation of CrO films.