Tantalum Dioxide Complexes with Dinitrogen. Formation and Characterization of the Side-on and End-on Bonded TaO2(NN)x (x = 1−3) Complexes
journal contributionposted on 12.08.2010, 00:00 by Caixia Wang, Jia Zhuang, Guanjun Wang, Mohua Chen, Yanying Zhao, Xuming Zheng, Mingfei Zhou
The reaction of tantalum dioxide molecule with dinitrogen has been studied by matrix isolation infrared spectroscopy. The tantalum dioxide molecules produced from laser evaporation of bulk Ta2O5 target reacted with dinitrogen to form the TaO2(η1-NN)x (x = 1−3) complexes on annealing, in which the N2 ligands are end-on bonded to the tantalum metal center. The TaO2(η1-NN)3 complex decomposed to TaO2(η1-NN)2 under infrared irradiation. The TaO2(η1-NN)2 and TaO2(η1-NN)3 complexes rearranged to the less stable TaO2(η1-NN)(η2-N2) and TaO2((η1-NN)2(η2-N2) isomers under visible light excitation. Both the mono- and bis-dinitrogen complexes were predicted to have 2A′ or 2A1 ground states arising from the 2A1 ground state of TaO2, whereas the two tridinitrogen complexes were predicted to have 2B2 ground states with C2v symmetry, which are derived from the 2B1 excited state of TaO2.