AN INVESTIGATION OF GROUP-(IV) ALKOXIDES AS PROPERTY CONTROLLING REAGENTS IN THE SYNTHESIS OF CERAMIC MATERIALS

Chemical synthetic methodologies are frequently employed to fabricate ceramic materials. To assist in determining methods for control over t he final properties of ceramic materials, we have begun an investigati on of the basic chemistry of sol-gel precursor solutions for lead zirc onate titanate (PZT) thin films. The reactions between ''M(OCHMe(2))(4 )'' (M = Ti, Zr) and acetic acid were monitored by H-1, C-13, O-17 NMR , and X-ray crystallography. The results of this investigation, the co mplexes generated, (Ti-6(OCHMe(2))(12)(OAc)(4)O-4, 1, Ti-6(OCHMe(2))(8 ),(OAc)(8)O-4, 2), and the types of films produced are reported. The s ynthesis of novel Group (IV) metal alkoxide complexes has been underta ken to generate precursors for ceramic materials with the desired char acteristics internalized. In an attempt to reduce hydrolysis, the form ation of a variety of metallo-organic compounds containing the sterica lly bulky adamantan-1-ol ligand (AdamO-H) was studied. It was demonstr ated that the OCHMe(2) ligands of ''M(OCHMe(2))(4)'' (M = Ti, Zr) were easily replaced with AdamO, forming compounds with the empirical form ula ''(AdamO)(n)M(OCHMe(2))(4-n),'' (n = 1,2, 3, or 4). Spin-cast depo sited films of these compounds were not affected by ambient humidity a nd crystallize upon evaporation of the solvent. Another set of alkoxid e ligands which has been investigated is a series of tridentate alkyl alkoxides: 1,1,1-tris(hydroxymethyl)ethane (THME-H-3), 1,1,1-tris(hydr oxymethyl)propane (THMP-H-3), 1,3,5-cyclohexanetriol (CYHT-H-3,), and 2,2-bis(hydroxymethyl) proprionic acid (BHMP-H-3). These ligands have been reacted with Group 4 metal alkoxides to form a variety of precurs ors that have been identified by spectroscopic and analytical methods. The THME and THMP ligated complexes are of the general formula (THMR) (2)M(4)(OCHMe(2))(10) [R = E, M = Ti, 3, and Zr, 4; R = P, M = Ti, 5 a nd Zr]. Films of these compounds demonstrate reduced susceptibility to hydrolysis when compared to the standard starting materials Ti(OCHMe( 2))(4), 6, and [Zr(OCHMe(2))(4) . HOCHMe(2)](2), 7.