FT-IR Spectroscopy of Acid-Modified Titanium Alkoxides: Investigations on the Nature of Carboxylate Coordination and Degree of Complexation

Modification of titanium butoxide by acetic acid has been studied by means of FT-IR spectroscopy. A deconvolution procedure was carried out to give further insight concerning the coordination modes of acetate ligands in Ti_aO_b(OBu)_c(OAc)_d complexes. From these results, molecular structures of the acetic acid modified precursor in a stoichiometric Ti(OBu)₄/AcOH (1:1) were proposed. On the basis of ATR spectroscopic data, the degree of complexation in Ti_aO_b(OBu)_c(OAc)_d oligomers as a function of the molar ratio Ti/AcOH was also estimated. Organic/inorganic hybrids were prepared from titanium butoxide and acrylic terpolymers bearing active acid groups via the sol-gel process. The interactions between the acid groups of the polymer and titanium butoxide were investigated by FT-IR spectroscopy and the carboxylate coordination modes were compared with the coordination modes in the acetato complexes.