Cationic Charges Leading to an Inverse Free‐Energy Relationship for N−N Bond Formation by Mn^VI Nitrides

Abstract

Mn N Schiff-base complexes incorporating a Na (1Na), K (1K), Ba (1Ba), or Sr (1Sr) ion in the ligand framework are reported. The Mn reduction potentials for 1Na, 1K, 1Ba, and 1Sr are 0.591, 0.616, 0.805, and 0.880 V vs. Fe(C H ) , respectively, exhibiting significant positive shifts compared to a MnN Schiff-base complex in the same primary coordination environment but with no associated alkali or alkaline earth metal ion (A, E =0.427 V vs. Fe(C H ) ). One-electron oxidation of the Mn N complexes results in bimolecular coupling to form N with rates (k ) at 20 °C of 2166, 684, 857, and 99.7, an 87 m s for A, 1Na, 1K, 1Ba, and 1Sr respectively, following an inverse linear free energy relationship. Thus, increasing charge through proximal cations results in Mn N complexes that are both more oxidizing and more stable to bimolecular coupling, a trend diametrically opposed to when complexes were modified by ligand substituents through inductive effects.

Installation of internal electric fields by non-redox active cations in transition metal complexes

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The Effect of Guest Metal Ions on the Reduction Potentials of Uranium(VI) Complexes: Experimental and Theoretical Investigations

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Dreyfus‐Preis und Camille‐Dreyfus‐Teacher‐Scholar‐Preise 2019

“…Yang untersucht die Grundlagen von Redoxreaktionen, um gezielt Katalysatoren für die Herstellung, Umwandlung und Nutzung chemischer Brennstoffe zu entwickeln. Sie berichtete in einer Angewandte‐Chemie ‐Zuschrift über eine inverse Freie‐Energie‐Beziehung für eine N‐N‐Verknüpfung durch Mangannitride …”