Charge-separated and molecular heterobimetallic rare earth-rare earth and alkaline earth-rare earth aryloxo complexes featuring intramolecular metal-pi-arene interactions

Deacon, Glen B., Junk, Peter C., Moxey, Graeme J., Ruhlandt-Senge, Karin, Prix, Courtney St., and Zuniga, Maria F. (2009) Charge-separated and molecular heterobimetallic rare earth-rare earth and alkaline earth-rare earth aryloxo complexes featuring intramolecular metal-pi-arene interactions. Chemistry, 15 (22). pp. 5503-5519.

[img] PDF (Published Version) - Published Version
Restricted to Repository staff only

View at Publisher Website: http://dx.doi.org/10.1002/chem.200900229
 
38
1


Abstract

A new family in town! Treatment of a rare-earth metal (Ln) and either a potential divalent rare-earth metal (Ln') or an alkaline earth metal (Ae) with 2,6-diphenylphenol (HOdpp) at elevated temperatures (200–250 °C) afforded heterobimetallic aryloxo complexes (see figure). Both a charge-separated species, [(Ln'/Ae)2(Odpp)3][Ln(Odpp)4], and a neutral species, [AeEu(Odpp)4], were obtained and crystallographically characterised. Treatment of a rare earth metal (Ln) and a potential divalent rare earth metal (Ln') or an alkaline earth metal (Ae) with 2,6-diphenylphenol (HOdpp) at elevated temperatures (200–250 °C) afforded heterobimetallic aryloxo complexes, which were structurally characterised. A charge-separated species [(Ln'/Ae)2(Odpp)3][Ln(Odpp)4] was obtained for a range of metals, demonstrating the similarities between the chemistry of the divalent rare earth metals and the alkaline earth metals. The [(Ln'/Ae)2(Odpp)3]+ cation in the heterobimetallic structures is unusual in that it consists solely of bridging aryloxide ligands. A molecular heterobimetallic species [AeEu(Odpp)4] (Ae=Ca, Sr, Ba) was obtained by treating an alkaline earth metal and Eu metal with HOdpp at elevated temperatures. Similarly, [BaSr(Odpp)4] was prepared by treating Ba metal and Sr metal with HOdpp. Treatment of [Ba2(Odpp)4] with [Mg(Odpp)2(thf)2] in toluene afforded [Ba2(Odpp)3][Mg(Odpp)3(thf)]. Analogous solution-based syntheses were not possible for [(Ln'/Ae)2(Odpp)3][Ln(Odpp)4] complexes, for which the free-metal route was essential. As a result of the absence of additional donor ligands, the crystal structures of the heterobimetallic complexes feature extensive π-Ph–metal interactions involving the pendant phenyl groups of the Odpp ligands, thus enabling the large electropositive metal atoms to attain coordination saturation. The charge-separated heterobimetallic species were purified by extraction with toluene/thf mixtures at ambient temperature (Ba-containing compounds) or by extraction with toluene under pressure above the boiling point of the solvent (other products). In donor solvents, heterobimetallic complexes other than those containing barium were found to fragment into homometallic species.

Item ID: 29700
Item Type: Article (Research - C1)
ISSN: 1521-3765
Keywords: alkaline earth metals, heterobimetallic complexes, O ligands, pi interactions, rare earths
Funders: Australian Research Council (ARC), Monash University, National Science Foundation, Syracuse University, WM Keck Foundation
Projects and Grants: National Science Foundation (CHE-0505863, 055273, 0753807, 9527858)
Date Deposited: 02 Oct 2013 10:34
FoR Codes: 03 CHEMICAL SCIENCES > 0302 Inorganic Chemistry > 030202 f-Block Chemistry @ 100%
SEO Codes: 97 EXPANDING KNOWLEDGE > 970103 Expanding Knowledge in the Chemical Sciences @ 100%
Downloads: Total: 1
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page