Observation of Terahertz Vibrations in the Nitrogenase FeMo Cofactor by Femtosecond Pump-Probe Spectroscopy

Pump it upl The FeMo cofactor (see picture) has resisted characterization by resonance Raman spectroscopy. Impulsive coherent vibrational spectroscopy may be an alternative probe of its dynamics. A 15 fs visible laser pulse pumped the sample to an excited electronic state, and a second < 10 fs pulse probed the change in transmission as a function of the time delay. (Figure Presented)