Tuning the Properties of Redox‐Active Guanidino‐Functionalized Aromatic Ligands by Substitution: Experiment and Theory

Abstract

Abstract Substitution of the aromatic hydrogen atoms in the electron donors 1,2,4,5‐tetrakis(tetramethylguanidino)benzene ( 1a ) and 1,2,4,5‐tetrakis( N , N ′‐dimethyl‐ N , N ′‐ethyleneguanidino)benzene ( 1b ) by iodide (to give 2a and 2b ) and nitro groups (to give 3a and 3b ) afforded new redox‐active ligands. Their properties (electron donor capacity, Brønsted basicity and optical spectra) have been analyzed and compared with the unsubstituted 1,2,4,5‐tetrakis(guanidino)benzenes. The experimental results are supplemented by quantum chemical calculations. The first late‐transition metal complex of the push–pull ligand 3a was prepared and characterized and its oxidation studied.