Titanium alkoxides heterometallic

Many low-valent heterometallic titanium-aluminium alkoxides that activate dinitrogen were reported in the reactions between titanium alkoxides and tri-alkylaluminium (113). 

Heterometallic oxo-alkoxides may also be formed by conversion from heterometallic alkoxides. Thus the insoluble [Pb(OPr)2]j reacted with Ti(OPr% to form [Pb4Ti403PPr g] and [Pb2Ti2(Ai4-0)(/u,3-0Pr )2(/Li-0Pr )4(0Pr )4] presumably by ether elimination. Similarly, from reactions of barium alkoxides and titanium alkoxides the heterometallic oxo-alkoxides [Ba4Ti404(OPr )i6(Pr OH)4][Ba4Ti404(OPr )io(Pr OH)3] and [Ba2Ti40(0Me)ig(Me0H)7]2° were obtained as a result of ether elimination, although similar complexes are readily prepared when the barium alkoxide solution is aerobically oxidized. ... 

Both homometallic and heterometallic oxo-alkoxides can be produced by partial hydrolysis of metal alkoxide precursors via dehydroxylation and dealkoxolation of metal hydroxo alkoxides. The crystal structures of a number of polynuclear titanium oxo alkoxides have been elucidated, these structures having evolved during the slow addition of small amounts of water to Ti(OEt)4 47,48,76-79... 

Table 4.20 Heterometallic alkoxides of titanium, zirconium, and hafnium...

Titanium Sub-group Metal-containing Oxo-alkoxides (Including Heterometallic Compounds) (Table 5.4)... 

Table 5.4 Titanium and zirconium-containing oxo-alkoxides (including heterometallic compounds) ...

A vanadium(v)-molybdenum(vi) heterometallic oxo-alkoxide [V2Mo2(0)g (0Me)2 (0CH2)3C(CH20H) 2] has also been characterized. The V2M02O16 core involving octahedral metals is reminiscent of the Ti40ie core of titanium tetraUcoxides. ... 

The first type of transformations is characteristic of both homo- and heterometallic derivatives and leads to formation of stable fully substituted complexes with chelating ligands from the mixed-ligand derivatives. It has been first observed and described in detail by Wengrovius (1986) for the alkoxide )8-diketonate derivatives of aluminium and then was studied also by Errington (1998) for the same type of titanium derivatives ... 

Kuhlman R., Vaarstra B.A., Streib W.E., Huffman J.C., Caulton K.G. Primary steps in the hydrolyses of two heterometallic alkoxides. Characterization of lithium-titanium and barium-zirconium isopropoxides [LiTiO(0-wo-Pr)3]4 and BaZr4(OH)(O-W0-Pr)i7. Inorg. Chem. 1993 32 ... 

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