in tetrahydrofuran byproducts: N2; (inert atm.); dissolving cobalt complex in THF, addn. of iron complex, stirring overnight; evapn. in vac., drying in vac., dissolving in THF, cooling to -40°C overnight;

in THF-d8 (tetrahydrofuran-d8) byproducts: N2; (inert atm.); addn. of THF-d8 to a mixt. of cobalt and iron complexes inan NMR tube; not isolated, detected by NMR;