Reversible Hydride Migration from C5Me5 to RhI Revealed by a Cooperative Bimetallic Approach.
The use of cyclopentadienyl ligands in organometallic chemistry and catalysis is ubiquitous, mostly due to their robust spectator role. Nonetheless, increasing examples of non-innocent behaviour are being documented. Here, we provide evidence for reversible intramolecular C-H activation at one methyl terminus of C5Me5 in [(η-C5Me5)Rh(PMe3)2] to form a new Rh-H bond, a process so far restricted to early transition metals. Experimental evidence was acquired from bimetallic rhodium/gold structures in which the gold center binds either to the rhodium atom or to the activated Cp* ring. Reversibility of the C-H activation event regenerates the RhI and AuI monometallic precursors, whose cooperative reactivity towards polar E-H bonds (E=O, N), including the N-H bonds in ammonia, can be understood in terms of bimetallic frustration.
['Alférez|Macarena G|MG|', 'Moreno|Juan J|JJ|', 'Hidalgo|Nereida|N|', 'Campos|Jesús|J|http://orcid.org/0000-0002-5155-1262']
hydride migration cyclopentadienyl ligands transition metals metal–ligand cooperation non-innocent ligands