Recent Studies on Nitrogenase

Vanadium, Molybdenum and Iron Complexes Based on a Trithiolate Ligand 

Semi-reduced, isolated FeMoco has not been observed to interact with N2, but kinetic studies have shown that it binds thiols and selenols (probably at the cysteinyl Fe), cyanide (at two sites, this Fe and the Mo) and protons (at the bridging sulfurs). Reduction of acetylene to ethylene and of protons to H2 has also been demonstrated with various preparations of isolated FeMoco.  

---