Editors : David B. Beach, Seshu B. Desu, Suleyman Gokoglu, Bruce W. Wessels
a1 NASA Lewis Research Center, Photovoltaic Branch, M.S. 302-1, Cleveland, OH 44135
a2 Department of Chemistry, Cleveland State University, Cleveland, OH, 44115
a3 School of Technology, Kent State University, Kent, OH 44242
a4 Sverdrup Technology, Inc., 2001 Aerospace Parkway, Brook Park, OH 44142
a5 Department of Chemistry, Purdue University, West Lafayette, IN 47907
Reaction of metallic indium with benzoyl peroxide in 4-methylpyridine (4-Mepy) at 25 °C produces an eight-coordinate mononuclear indium(III) benzoate, In(η2-O2CC6H5)3(4- Mepy)2 4H2O (I), in yields of up to 60%. The indium(III) benzoate was fully characterized by elemental analysis, spectroscopy, and X-ray crystallography; (I) exists in the crystalline state as discrete eight-coordinate molecules; the coordination sphere around the central indium atom is best described as pseudo-square pyramidal. Thermogravimetric analysis of (I) and X-ray diffraction powder studies on the resulting pyrolysate demonstrate that this new benzoate is an inorganic precursor to indium oxide. Decomposition of (I) occurs first by loss of 4-methylpyridine ligands (100°-200°C), then loss of benzoates with formation of In2O3 at 450°C. We discuss both use of carboxylates as precursors and our approach to their preparation.