Lithium and sodium N,N′-di(2,6-dialkylphenyl)formamidinate complexes

A study has been undertaken of the lithium and sodium metallation of N,N′-di(aryl)formamidines with alkyl groups at the 2- and 6-aryl position. 1H NMR and X-ray diffraction data indicate an increase in steric bulk from 2,6-dimethylphenyl to 2,6-diethylphenyl to 2,6-diisopropylphenyl incites incremental changes in amidinate binding and nuclearity. In selected instances, this invokes the first lithium and sodium amidinate/guanidinate complexes to exhibit metal–arene contacts.