Details

Autor(en) / Beteiligte

• Boyle, Timothy J
• Sewell, Robin M
• Ottley, Leigh Anna M
• Pratt, Harry D
• Quintana, Christopher J
• Bunge, Scott D

Titel

Controlled Synthesis of a Structurally Characterized Family of Sterically Constrained Heterocyclic Alkoxy-Modified Titanium Alkoxides

Ist Teil von

• Inorganic chemistry, 2007-03, Vol.46 (5), p.1825-1835

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2007

Quelle

MEDLINE

Beschreibungen/Notizen

• The reaction of [Ti(μ-ONep)(ONep)3]2 (ONep = OCH2C(CH3)3) with a series of heterocyclic methanol derivatives [tetrahydrofurfuryl alcohol (H−OTHF), thiophene methanol (H−OTPM), or 2-pyridylcarbinol (H−OPy)collectively termed H−OR*], led to the isolation of a novel family of OR*-substituted titanium alkoxide precursors. Independent of the initial stoichiometry for the H−OTHF reaction, a monosubstituted, dinuclear species was isolated as [(ONep)3Ti(μc-OTHF)]2 (1). For 1, each Ti was octahedrally (Oh) bound by three terminal ONep ligands, one bidentate bridging OTHF ligand (μc-OTHF), and an oxygen from the other μc-OTHF ligand. For the OTPM derivatives, the product was identified as [(ONep)3Ti(μ-OTPM)]2 (2). For this ligand, the soft S atom does not bind to the Ti but the O atom does act as a bridge between the two trigonal bipyramidal bound Ti metal centers. The OPy system yielded (OPy)2Ti(OR)2 independent of the OR and the stoichiometry used [OR = ONep (3), OCHMe2 (4), OCMe3 (5)]. For 3−5, the two OPy ligands chelate to the Oh-bound Ti metal center with two terminal OR ligands. Compounds 1−5 were fully characterized using a variety of analytical techniques. An initial investigation of the proposed chemical stability of the ‘(OPy)2Ti' moiety of 3−5 to alcoholysis exchange pathways involving (i) alkyl alcohols, (ii) aryl alcohols, (iii) substituted phenols, (iv) H−OR* derivatives, and (v) silanols proved successful through the isolation of a novel family of structurally characterized (OPy)2Ti(OR‘)2 (7−24) compounds.