NacNac

[1] Acetylacetone and related 1,3-diketones condense with primary alkyl- or arylamines resulting in replacement of the carbonyl oxygen atoms with NR groups, where R = aryl, alkyl.

To prepare 1,3-diketimines from bulky amines, e.g. 2,4,6-trimethylanilines, prolonged reaction times are required.

Deprotonation of HNacNac compounds affords anionic bidentate ligands that form a variety of coordination complexes.

[3] Unlike the situation for the acetylacetonates, the steric properties of the coordinating atoms in NacNac− ligands is adjustable by changes in the R substituent.

Attachment to a metal center is usually carried out by initial deprotonation of HNacNac with n-butyllithium; the lithium derivative is then treated with a metal chloride to eliminate lithium chloride.

Tautomers of a substituted HNacNac ligand precursor and an idealized complex (right) of the conjugate base (M = metal, L = other ligand)
Structure of [(C 6 H 3 -2,6-(i-Pr) 2 ) 2 NacNac]NiSCPh 3 viewed down the C 2 axis, illustrating the steric bulk of this NacNac ligand (CPh 3 removed for clarity). Color code=gray = C, white = H, blue=N, yellow=S, green=Ni). [ 4 ]
Synthesis of Jäger's N 2 O 2 ligand. [ 5 ]