Divergent Malonamides/Ti(NMe2)4 System for the Synthesis of Mono-, Bis-, and Tris(dimethylamide)-Titanium(IV) Complexes

Modifying the synthesis time and temperature in the reaction of 2,2-dimethyl-N,N′-dimesityl-propanediamide (H₂DMDMMA) and 2,2-dimethyl-N,N′-ditert-butyl-propanediamide (H₂DTDMMA) with Ti(NMe₂)₄ produces five distinct titanium amide malonamides (4–8). Three, two, or one −NMe₂ group is present in these complexes, all of which are cis-OO′ chelated except for one with a unique cis-NO chelate.In the literature, a variety of synthetic methodologies for malonamides (MAs is informed. The chelating features of MAs have been the subject of extensive investigation for use in liquid extraction of lanthanides (Ln) and actinides (An). However, no comparative study has explored the substituents influence the nucleophilic behavior of anionic MAs in their role as ligands. Herein, we present insight into the divergent 2,2-dimethyl-N,N′-dimesityl-propanediamide (H₂DMDMMA) and 2,2-dimethyl-N,N′-ditert-butyl-propanediamide (H₂DTDMMA)/ tetrakis(dimethylamido)titanium [Ti(NMe₂)₄] system, which allowed a collection of five complexes. The titanium amide malonamides obtained have three, two, or one -NMe₂ group and are cis-OO′ chelated, except for one complex that exhibits the unprecedented cis-NO chelate mode.