Tantalum complexes alkoxo

We then studied group 5 metals, especially tantalum-for which the laboratory already had great experience. Because of the studied reaction, alkyl or hydride-type compounds such as those developed in the laboratory could not be employed. Consequently, we became interested in alkoxo-type derivatives, either synthesized by reaction of the grafted complex with an alcohol or obtained by direct synthesis starting from an alkoxy-tantalum compound grafted on silica. In all cases, resulting complexes have been characterized by surface organometallic chemistry techniques, especially EXAFS and solid-state NMR (ID and 2D with C-labeled compounds). Indeed various compounds bonded by one, two or three surface bonds have been prepared and characterized. 

Reactions between MClj and hydrogen phosphonates (HL = (RO)2P(0)H R = Et, Pr", Bu, Ph) afforded [MCls L ] (jc = 1-3), wWch were reported to be polymeric through —O— P—O bridges. NbXs when allowed to react with Na[S2P(OR)2] (R = Me, Et, cyclohexyl) gave [Nb(OMe)2Cl S2P(OR)2 2] recrystallization from the appropropriate alcohol afforded complexes having other alkoxo groups. The reaction of dithiophosphates with TaXs did not afford the analogous tantalum derivatives. 

Tantalum(III) complexes, 655-667 activation reactions, 660 alkoxo, 664 carboxylatotrihalo, 664 dialkylphosphido, 665 3-diketonatotribalo, 664 dithiocarbamato, 664 halo... 

Tantalum(IV) complexes, 639-655 activation of small molecules, 654 alkoxo, 649 alkylamido, 652 carboxylato, 650 chalcogeno, 654 clusters, 667... 

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