Nitrogen Fixation by Manganese Complexes - Waiting for the Rush?

Manganese is currently experiencing a great deal of attention in homogeneous catalysis as a sustainable alternative to platinum group metals due to its abundance, affordable price and low toxicity. While homogeneous nitrogen fixation employing well-defined transition metal complexes has been an important part of coordination chemistry, manganese derivatives have been only sporadically used in this research area. In this contribution, the authors systematically cover manganese organometallic chemistry related to N2 activation spanning almost 60 years, identify apparent pitfalls and outline encouraging perspectives for its future development. In the context of nitrogen fixation, manganese complexes seem to be set back when compared to other early-to-mid transition metals. This does not reflect the rush this metal has experienced in homogeneous hydrogenation catalysis and related processes. Giving an overview of the relevant literature, the authors attempt to answer why this metal has not yet made its breakthrough in N2 activation. image