Heterometallic Mg−Ba Hydride Clusters in Hydrogenation Catalysis. Issue 21 (7th September 2021)

• Record Type: Journal Article
• Authors: Wiesinger, Michael; Knüpfer, Christian; Elsen, Holger; Mai, Jonathan; Langer, Jens; Harder, Sjoerd
• Is Part Of: ChemCatChem. Volume 13:Issue 21(2021)
• Page Start: 4567
• Page End: 4577
• Publication Date: 2021-09-07
• Subjects: alkaline earth metal -- hydride -- heterometallic -- catalysis -- DFT calculations; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.202101071
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: Reaction of a MgN"2 /BaN"2 mixture (N"=N(SiMe3 )2 ) with PhSiH3 gave three unique heterometallic Mg/Ba hydride clusters: Mg5 Ba4 H11 N"7 ⋅ (benzene)2 (1 ), Mg4 Ba7 H13 N"9 ⋅ (toluene)2 (2 ) and Mg7 Ba12 H26 N"12 (3 ). Product formation is controlled by the Mg/Ba ratio and temperature. Crystal structures are described. While 3 is fully insoluble, clusters 1 and 2 retain their structures in aromatic solvents. DFT calculations and AIM analyses indicate highly ionic bonding with Mg−H and Ba−H bond paths. Also unusual H − ⋅⋅⋅H − bond paths are observed. Catalytic hydrogenation with MgN"2, BaN"2 and the mixture MgN"2 /BaN"2 has been studied. Whereas MgN"2 is only active in imine hydrogenation, alkene and alkyne hydrogenation needs the presence of Ba. The catalytic activity of the MgN"2 /BaN"2 mixture lies in general between that of its individual components and strong cooperative effects are not evident. Abstract : Heterometallic catalysis : Three different Mg/Ba hydride clusters have been prepared and were studied in the solid state and in solution. Cooperative effects between Mg and Ba in hydrogenation catalysis have been evaluated.