Structural Investigation of Pyridinecarboxylato Titanium(IV) Complexes: An Uncommon Monomeric Octacoordinated Complex vs. a Hexaprismatic Architecture.

We report the synthesis and structural characterisation of two titanium(IV) complexes. A new titanium(IV) complex bearing four picolinato ligands, denoted as Ti(pic)4, has been prepared under solvothermal conditions. This complex identified by single-crystal diffraction is a new example of an octacoordinated environment for titanium(IV) and is close to an ideal triangular dodecahedron. A second synthesis of a hexaprismatric carboxylato titanium complex formulated as [Ti6(μ3-O)6(O iPr)6(μ-O2CC5H3NCOO iPr)6] starting from a dissymmetric anhydride pyridine carboxylic precursor is described. The solid-state analysis shows the presence of a single compound among 13 possible species. Calculations gave evidence of a highly selective mechanism leading to the formation of the final product. [ABSTRACT FROM AUTHOR]