Evidence for the formation of (NN)xMN(M=Os and Ru) (x=1–3) complexes

Abstract

MN and their N2 complexes (NN)MN, (NN)2MN, and (NN)3MN (M=Os and Ru) were obtained in the reaction of laser-ablated transition metal Os and Ru atoms with nitrogen in excess solid argon at 4 K through matrix isolation infrared spectroscopy and quantum chemical calculations. The maximum coordinated N2 number is got according to the energy surface. With the increase of coordinated number, the M-N bond length increase in accordance with the red shift of M-N stretching mode from 1130.2 cm−1 to 1052.1 cm−1 for OsN series and from 1119.1 cm−1 to 984.1 cm−1 for RuN series. In addition, a new product (NN)2NOsOsN(NN)2 was discovered in the reaction of laser-ablated Os with N2 in N2 matrix, which could be regarded as NOsOsN coordinated by four N2 molecules. The reason that growth of M-N bond length in (NN)xMN with the N2 coordination was explained in detail, which was mainly caused by relativistic effect.