Synthesis and Structural Characterization of a New Heterobimetallic Coordination Complex of Barium and Cobalt for Use as a Precursor for Chemical Vapor Deposition

Ba(dmae)2 (dmaeH = N,N-dimethylaminoethanol, C4H11NO) reacts with Co(acac)2 (acac = 2,4-pentanedionate) to
produce the trinuclear coordination complex [Ba2Co(acac)4(dmae)3(dmaeH)] in an 85% yield. Spectroscopic and
single-crystal X-ray diffraction experiments indicate that the complex possesses a structure in which two barium
atoms and a cobalt atom are bridged by acac and dmae groups. The barium centers are eight and nine coordinate
with BaO7N and BaO7N2 coordination spheres while the cobalt is a more regular CoO5N octahedron. This 2:1
heterobimetallic molecular complex was investigated as precursor for the deposition of thin film by AACVD. The
film was characterized by SEM and XRD. TGA shows that the complex starts thermal decomposition upon heating
in nitrogen atmosphere at 105 °C to produce barium cobalt oxide material of a Ba2CoO3 composition with an
orthorhombic structure. The synthetic approach detailed here represents a unique route to the formation of a
heterobimetallic barium cobalt coordination complex.