N2 activation by iron-sulfur complexes

Inspired by the determination of the structure of the nitrogenase enzyme cofactor by Rees et al., the binding of an N₂ molecule to some model iron-sulfur compounds was investigated usingab initio calculations. Side-on and end-on coordination to one two and four iron centers were investigated. In most cases, the N₂ is loosely bound and retains its internal triple bond, but a few examples are found where the N₂ is “activated” and has a longer N-N bond length.