Knowledge Bank

Metal cation-nitrogen clusters, $M+(N2)n$, of the first row transition metals are produced in a laser vaporization pulsed nozzle cluster source, size selected and excited in the infrared with an infrared OPO/OPA. Infrared photodissociation occurs by elimination of whole $N2$ molecules and the photofragement yield versus wavelength produces IR resonance-enhanced photodissociation (REPD) spectra for the clusters. Vibrational bands seen in the 2100 to $2400cm-1$ region correspond to the N-N stretch but are shifted from those of free $N2$. Density functional theory calculations on the bond enegeries, geometries and frequency shifts for first row $M+(N2)$ are also discussed in regard to periodic trends.