Preparation and structures of complexes of titanium(IV) and 8-hydroxyquinoline: TiQ2(Opri)2 and [TiQ2(μ-O)]4·6H2O

Autor: Yen S. Chen, Shuenn Shing Chern, Wen Fong Zeng, Michael Y. Chiang, Cheu Pyeng Cheng
Rok vydání: 2002
Předmět:
Zdroj: Polyhedron. 21:1081-1087
ISSN: 0277-5387
DOI: 10.1016/s0277-5387(02)00873-2
Popis: The reaction between Ti(OPri)4 and 8-hydroxyquinoline (HQ) resulted in TiQ2(OPri)2, 1 in 90% yield. Further reaction of 1 with water yielded [TiQ2(μ-O)]4·nH2O, 2·nH2O, n=2 or 6 depending on whether the sample was dried. The structures of 1 and 2·6H2O were determined by X-ray diffraction method. In 1 and 2 the bonding situations around the pseudo-octahedrally coordinated Ti(IV) are very similar. The two oxygen atoms from Q− ligands are trans to each other, while the two nitrogen atoms are cis to each other and trans to the other two oxygen atoms of OPri in 1 and μ-O in 2. The [Ti(μ-O)]4 eight-membered ring is puckered. There is extensive hydrogen bonding of four water molecules with [TiQ2(μ-O)]4, two on each side of the eight-membered ring of [Ti(μ-O)]4. The two water molecules on the same face of the eight-membered ring are further hydrogen bonded to another water molecule. A novel feature in 2 is that the plane of each Q− ligand is parallel to that of another Q− ligand coordinated to a neighboring Ti(IV) in an eclipsed conformation. The average distance between the corresponding atoms in the parallel Q− ligands is 3.6 A. It is an indication that there is a strong non-bonding interaction between each pair of parallel Q− ligands. The hydrogen bonds and the non-bonding interactions lead to the most severely distorted plane of the [Ti(μ-O)]4 eight-membered ring.
Databáze: OpenAIRE
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