Structural and thermal stability studies of Ti(IV) hexanuclear oxo trimethylacetato isopropoxide complex

• Published in: Inorganica Chimica Acta Vol. 357; no. 9; pp. 2769 - 2775
• Main Authors: Piszczek, P, Grodzicki, A, Richert, M, Wojtczak, A
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.07.2004
• Subjects: Carboxylato complexes; Crystal structure; NMR and IR characteristics; Thermogravimetric and MS analysis; Titanium alkoxides; Thermogravimetric and MS analysis; Titanium alkoxides; NMR and IR characteristics; Carboxylato complexes; Crystal structure
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2004.02.022

Titanium(IV) hexanuclear oxo trimethylacetato isopropoxide complex has been synthesized in a reaction of titanium isopropoxide (Ti(OPr i ) 4) with Bu t COOH in the ratio 1:1. The structure was analyzed with the elemental analysis, IR and NMR spectroscopy, and X-ray singe-crystal diffraction methods. Titanium atoms form the hexanuclear cluster, where three μ 3-oxo, two μ-carboxylato bridges and the terminal alkoxide ligand, in the distorted octahedron, surround each central cation. Thermal stability of this compound was studied by TGA and MS methods. A new titanium hexanuclear oxo carboxylato alkoxide complex, with the general formula [Ti 6O 6(OPr i ) 6(OOCBu t ) 6] ( 1), has been synthesized in a reaction of titanium isopropoxide (Ti(OPr i ) 4) with Bu t COOH in the ratio 1:1. The structure was analyzed with the elemental analysis, IR and NMR spectroscopy, and X-ray single-crystal diffraction methods. Crystal structure of 1 was solved in the trigonal centrosymmetric system R 3 ̄ r . Titanium atoms form the hexanuclear cluster, where three μ 3-oxo, two μ-carboxylato bridges and the terminal alkoxide ligand, in the distorted octahedron, surround each central cation. Analysis of spectroscopic data revealed a significant nonequivalence of interactions formed by the carboxylate groups, resulting from the asymmetry of Ti-μ-OOC bonds of carboxylate bridges in the complex molecule. TGA and MS studies suggest that volatile, titanium hexanuclear species may be formed between 423 and 553 K.