Reactivity of yttrium carboxylates toward alkylaluminum hydrides

Christoph Schädle; Andreas Fischbach; Eberhardt Herdtweck; Karl W Törnroos; Reiner Anwander

doi:10.1002/chem.201302944

Reactivity of yttrium carboxylates toward alkylaluminum hydrides

Chemistry. 2013 Nov 25;19(48):16334-41. doi: 10.1002/chem.201302944. Epub 2013 Oct 21.

Authors

Christoph Schädle¹, Andreas Fischbach, Eberhardt Herdtweck, Karl W Törnroos, Reiner Anwander

Affiliation

¹ Department of Inorganic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen (Germany), Fax: (+49) 7071-29-2436.

PMID: 24151216
DOI: 10.1002/chem.201302944

Abstract

Yttrocene-carboxylate complex [Cp*2Y(OOCAr(Me))] (Cp*=C5Me5, Ar(Me) =C6H2Me3-2,4,6) was synthesized as a spectroscopically versatile model system for investigating the reactivity of alkylaluminum hydrides towards rare-earth-metal carboxylates. Equimolar reactions with bis-neosilylaluminum hydride and dimethylaluminum hydride gave adduct complexes of the general formula [Cp*2Y(μ-OOCAr(Me))(μ-H)AlR2] (R=CH2SiMe3, Me). The use of an excess of the respective aluminum hydride led to the formation of product mixtures, from which the yttrium-aluminum-hydride complex [{Cp*2Y(μ-H)AlMe2(μ-H)AlMe2(μ-CH3)}2] could be isolated, which features a 12-membered-ring structure. The adduct complexes [Cp*2Y(μ-OOCAr(Me))(μ-H)AlR2] display identical (1)J(Y,H) coupling constants of 24.5 Hz for the bridging hydrido ligands and similar (89)Y NMR shifts of δ=-88.1 ppm (R=CH2SiMe3) and δ=-86.3 ppm (R=Me) in the (89)Y DEPT45 NMR experiments.

Keywords: aluminum; carboxylato ligands; hydrides; reaction mechanisms; yttrium.