Solid state π-π stacking and higher order dimensional crystal packing, reactivity, and electrochemical behaviour of salphenazine actinide and transition metal complexes

Condensation of a 2,3-diaminophenazine or 2,3-diamino-2-quinoxalinol with two equivalents of 3,5-ditertbutylsalicylaldehyde affords new Schiff base ligands. Here, we describe and compare the synthesis, UV-Vis, electrochemical, solution, and solid state behaviour of the free base, salphenazine ligand [L I ], and M[L I ] complexes, where M = UO 2 ( vi ), Cu( ii ), VO( iv ), Zn( ii ), Co( ii ), and Ni( ii ). The change in π-overlap and π-stacking between molecules and long-range ordering of the solid-state structure is vastly different depending on the size and electronic character of the metal. A sterically constrained μ-oxo Fe( iii ) dimer complex is also reported. Here, we describe and compare the synthesis, solution characterization, and solid-state behaviour of the salphenazine ligand and metal complexes.