Tuning the redox properties of a 1-D supramolecular array via selective deprotonation of coordinated imidazoles around a Mn(II) center

A neutral 1-D supramolecular array containing [Mn(H2)2] building blocks was synthesized by the selective deprotonation of two coordinated imidazole moieties from the cationic Mn(II) complex, [Mn(H22)2]2+. Upon deprotonation the redox potential of [Mn(H2)2] shifts significantly more negative, when compared to the cationic Mn(II) complex. However, X-ray crystallographic studies done on both complexes show a very similarly distorted octahedral geometry around the Mn(II) ion. Interestingly, while [Mn(H2)2] lacks both charge and counterion to assist in crystal packing, both the neutral and cationic complexes self-organize, using primarily π–π and edge-to-π aryl interactions, into very similar 1-D zigzag ribbons in the solid-state.