Reductive activation of N 2 using a calcium/potassium bimetallic system supported by an extremely bulky diamide ligand
Résumé
An extremely bulky xanthene bridged diamide ligand ((NON)-N-TCHP = 4,5-bis(2,4,6-tricyclohexylanilido)-2,7-diethyl-9,9-dimethyl-xanthene) has been developed and used to prepare two monomeric diamido-calcium complexes [((NON)-N-TCHP)Ca(D)(n)] (D = THF, n = 2, 3; D = toluene, n = 1, 4). Reduction of 4 with 5% w/w K/KI under an N-2 atmosphere gave the first well-defined, hetero-bimetallic s-block complex of activated dinitrogen, [{K((NON)-N-TCHP)Ca}(2)(mu-eta(2):eta(2)-N-2)] 5, presumably via a transient calcium(i) intermediate.