Ethyl acetoacetate ligand distribution in the course of titanium n-butoxide chelation

• Published in: Materials chemistry and physics 2014-10, Vol.147 (3), p.1058-1067
• Main Authors: Kurajica, S., Škorić, I., Lozić, I., Mandić, V.
• Format: Article
• Language: English
• Subjects: Fourier transform infrared spectroscopy (FTIR); Nanostructures; Nuclear magnetic resonance (NMR); Organometallic compounds
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2014.06.059

Sols obtained by chelation of titanium n-butoxide with ethyl acetoacetate, Eaa, in various ratios have been subjected to FTIR, 1H and 13C NMR, HSQC and UV–Vis spectroscopy in order to provide insight in the compounds obtained, their structure and quantitative relationships. Three compounds, the bis-chelated monomer, Ti(OnBu)2(Eaa)2, bis-chelated dimer, (Ti(OnBu)3Eaa)2 and monochelated dimer, Ti2(OnBu)7Eaa have been established. As the molar ratio Eaa/Ti(OnBu)4 increases, the coordination changes from the monochelated and bis-chelated dimer to the bis-chelated monomer. Additionally, the transesterification reaction, influencing the chemical composition of the compounds was noted. The hydrolysis of the prepared sols was partial, leaving some residual butoxy and ethyl acetoacetate groups attached to titanium. Thermal treatment of the prepared amorphous gels at 350 °C yielded with the formation of nanocrystalline anatase. It was noted that high Eaa/Tnb ratio slightly retards the anatase formation. [Display omitted] •Titanium n-butoxide was modified with ethyl acetoacetate in various ratios.•Among other chelate phases, previously undescribed Ti2(OnBu)7Eaa was obtained.•NMR-based mass balance procedure was introduced to obtain quantitative relationships.•The transesterification reaction has been noted.•Nanocrystalline anatase has been obtained by thermal treatment at 350 °C.