Salt metathesis as an alternative approach to access aluminium(i) and gallium(i) β-diketiminates.

Salt metathesis, i.e. the reaction of sodium β-diketiminate with (AlCp*)4 and GaCp*, respectively, is a valuable pathway to access the respective aluminium(i) and gallium(i) β-diketiminates I and II. The protocol gives better yields compared to the established procedures and avoids the use of strong reducing agents such as metallic potassium. Furthermore, the aluminium(i) β-diketiminate I was found to react with itself and yields upon C-N bond cleavage and hydrogen-atom transfer the asymmetric dinuclear aluminium(iii) complex V that is readily separated from I by crystallisation. The reaction mechanism has been probed by means of DFT and DLPNO-CCSD(T) calculations and the computational findings are in good agreement with the experimental observations.