Rhodium dinitrogen complexes Rh(NN)x (x=1-3) and anions:: Matrix infrared spectra and DFT calculations

Reactions of laser-ablated rhodium atoms with molecular nitrogen in excess neon produce the rhodium nitrogen complexes Rh(NN)(x) (x = 1-3) and their counterpart anions through the capture of ablated electrons. The observed absorption bands are identified by isotopic substitution and DFT calculations of vibrational fundamentals. The N-N stretching fundamental at 2162.0 cm(-1) for RhNN and the antisymmetric N-N mode for Rh(NN)(2) at 2199.3 cm(-1) in solid neon are in accord with earlier argon matrix assignments. Three N-N stretching frequencies at 2185.2, 2203.3, and 2235.6 cm(-1) are assigned to Rh(NN)3, which is calculated to have a T-shaped structure with a (2)A(1) ground state. The photosensitive Rh(NN)(x)(-) (x = 1-3) anions are eliminated with CCI4 doping to capture ablated electrons.