Structural investigation of the hydrolysis-condensation process of modified titanium isopropoxide

The structures of modified Ti(OPri)(4) with chelating ligands (L) such as e thylaceroacetate (Etac), acetylacetone (Acac) and methylacetoacetate (Mtac) were identified by using IRI H-1 NMR and C-13 NMR spectroscopies, and the octahedral structure was confirmed after modification. The pre-edge peaks o f XANES spectra of modified metal alkoxides also denoted the mixture of fiv e-fold and six-fold structures. The EXAFS fitting results showed the local structure around Ti atom after alkoxide modification. The hydrolysis-conden sation rates of modified Ti alkoxide with organic additives were investigat ed by H-1 NMR spectroscopy, The Ti(OPri)(4) modified by Acac was less react ive toward hydrolysis-condensation reaction than those modified by the othe r alkoxides, which can be attributed to the stable ligand structure between Ti(OPri)(4) and Acac. The small pal-tide size of modified Ti(OPri)(4) sol was obtained when Acac was employed.