Effect of the ligand conformation on the properties of complexes of Mn(II) and Zn(II) with asymmetric diimines | Poster Board #2532

Asymmetric (E)-[(2-pyridyl)methylene]aniline ligands (abbreviated ppa^X, where X is the substituent on the aniline ring) have been reported in complexes of a multitude of divalent transition metals (Fe, Ni, Pd, Cd, Zn, Mn, etc.). The electronic and spectroscopic properties of such complexes seem to be markedly affected by the conformation of the ligand: in some cases, this effect is even stronger than that of the substituents on the aniline ring. Despite numerous reports on complexes of this kind, there has not been a systematic study of how the substitution pattern of the ligand and its conformation affect the properties of such complexes.
We have prepared a series of Mn(II) and Zn(II) ppa^X complexes to better understand the relationship between the conformation of the ligand, the identity of its substituents, and its electronic properties, as well as the properties of the corresponding coordination complexes. Herein, we report the syntheses of the ppa^X ligands and their transition-metal complexes, describe their crystal structures, and use optical spectroscopy and electrochemistry to interrogate the properties of these compounds.