Steric Control in Low-Valent Mn Diamide Complexes: Contrasting Magnesium and Manganese in N2 and Benzene Activation.

Reduction of MnII precursors with bulky diamide ligands provided access to a complex with the longest known Mn-Mn bond and to a rare example of N2 activation at high-spin MnI centers. While some instructive parallels can thus be drawn to observations made for Mg analogues, the accessibility of filled d orbitals in the respective MnI intermediates leads to a distinct behavior toward benzene that undergoes an oxidative addition.