Dinitrogen Activation By A Penta-Pyridyl Molybdenum Complex

A new dinitrogen (N-2) molybdenum(0) complex supported exclusively by pyridine ligands was synthesized. The X-ray crystal structure of the complex elucidated the activated nature of the N-2 ligand, consistent with a low N-N IR stretching frequency. Natural bond orbital (NBO) analyses on this system confirmed a strong pi-backdonation arising from the large p orbital character in molybdenum lone pairs. The protonation of the N-2 ligand using decamethyl chromocene (CrCp*(2)) in the presence of lutidinium salt afforded 1.22 equivalents of ammonia (NH3).