Abstract
The reaction of phenazine with standard aluminum alkyls AlR3 (R = Me (a), Et (b), Et/Cl (c), i-Bu (d)) afforded, after initial coordination and formation of [AlMe3](2)(mu-eta(1):eta(1)-C12H8N2) (1), a further slow and complex transformation. As a result, the dinuclear and diamagnetic [AlR2](2)(mu-eta(1):eta(1)-C12H8N2)(2) (R = Me (2a), Et (2b), Et/Cl (2c), i-Bu (2d)) were formed in parallel to the paramagnetic and monomeric (AlR3)[eta(1)-C14H13NN(R)] (3). The diamagnetism of 2 is obtained via dimerization and implementation of an efficient intramolecular antiferromagnetic coupling. In the case of the reaction with Et2AlCl, the corresponding (AlEtCl2)[eta(1)-C14H13NN(Et)] (3c) was isolated and fully characterized. In all the other cases, only compelling ESR evidence was obtained for b the formation of isostructural species. On the basis of the isolation of both 2c and 3c from the same reaction, a mechanism is proposed involving ligand-assisted homolysis of Al-C bonds.