15min:

E. D. PILLAI AND M. A. DUNCAN, University of Georgia, Department of Chemistry, Athens, GA, 30602-2556.

Transition metal-nitrogen complexes of the form TM⁺(N₂)_n (TM=V, Fe, Nb) are produced in a laser vaporization pulsed nozzle cluster source, size selected with a time-of-flight mass spectrometer 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 - 2400 cm^-1 region correspond to the N-N stretch but are shifted from those of free N₂. Density functional theory calculations on the bond energeries, geometries and frequency shifts for the TM⁺(N₂)_n are also discussed in regard to periodic trends.