Reactivity of Hydride Bridges in High-Spin [3M–3(μ-H)] Clusters (M = FeII, CoII)

• Published in: Journal of the American Chemical Society Vol. 137; no. 33; pp. 10610 - 10617
• Main Authors: Lee, Yousoon, Anderton, Kevin J, Sloane, Forrest T, Ermert, David M, Abboud, Khalil A, García-Serres, Ricardo, Murray, Leslie J
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 26.08.2015
• Subjects: Chemical Sciences; Coordination chemistry; Physics
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.5b05204

The designed [3M–3­(μ-H)] clusters (M = FeII, CoII) Fe3H3L (1-H) and Co3H3L (2-H) [where L3– is a tris­(β-diketiminate) cyclophane] were synthesized by treating the corresponding M3Br3L complexes with KBEt3H. From single-crystal X-ray analysis, the hydride ligands are sterically protected by the cyclophane ligand, and these complexes selectively react with CO2 over other unsaturated substrates (e.g., CS2, Me3SiCCH, C2H2, and CH3CN). The reaction of 1-H or 2-H with CO2 at room temperature yielded Fe3(OCHO)­(H)2L (1-CO 2 ) or Co3(OCHO)­(H)2L (2-CO 2 ), respectively, which evidence the differential reactivity of the hydride ligands within these complexes. The analogous reactions at elevated temperatures revealed a distinct difference in the reactivity pattern for 2-H as compared to 1-H; Fe3(OCHO)3L (1-3CO 2 ) was generated from 1-H, while 2-H afforded only 2-CO 2 .