The hangman effect boosts hydrogen production by a manganese terpyridine complex.

The manganese terpyridine complex 1 with a coordinated carboxylate in the axial position was obtained in situ . By virtue of a hangman effect, complex 1 catalyzes electrochemical hydrogen evolution from phenol in acetonitrile solution with a turnover frequency of 525 s -1 at a low overpotential of ca. 230 mV.