A bio-inspired heterodinuclear hydrogenase CoFe complex

Herein, a new heterobimetallic CoFe complex is reported with the aim of comparing its performance in terms of H-2 production within a series of related MFe complexes (M = Ni, Fe). The fully oxidized [(L-N2S2)Co-II(CO)(FeCp)-Cp-II](+) complex ((CoFeII)-Fe-II, LN2S2 2- = 2,2 '-(2,2 '-bipyridine-6,6 '-diyl)bis(1,1 '-diphenylethanethiolate), Cp- = cyclopentadienyl anion) can be (electro)chemically reduced to its (CoFeII)-Fe-I form, and both complexes have been isolated and fully characterized by means of classic spectroscopic techniques and theoretical calculations. The redox properties of (CoFeII)-Fe-II have been investigated in DMF, revealing that this complex is the easiest to reduce by one-electron among the analogous MFe complexes (M = Ni, Fe, Co). Nevertheless, it displays no electrocatalytic activity for H-2 production, contrary to the FeFe and NiFe analogs, which have proven remarkable performance.