Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (06): 1346-1356.doi: 10.3866/PKU.WHXB20110522

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Structures and Properties of NFeN and the Reaction Potential Energy Curves

CAI Yue-Piao, WANG Chao-Jie   

  1. School of Pharmacy, Wenzhou Medical College, Wenzhou 325035, Zhejiang Province, P. R. China
  • Received:2011-02-24 Revised:2011-03-21 Published:2011-05-31
  • Contact: WANG Chao-Jie E-mail:chjwang@wzmc.edu.cn
  • Supported by:

    The project was supported by the Natural Science Foundation of Zhejiang Province, China (Y404085) and Foundation of Science and Technology Bureau of Wenzhou City, Zhejiang Province, China (Y20080103).

Abstract:

The geometrical structures, electronic structures, energetics and vibrational frequencies of bent and linear NFeN molecules with different spin multiplicities were studied at the B3LYP/6-311+G(d) level. We find that: (1) the Fe―N bond length is about 155 pm for singlet states and this is shorter than those in triplets and in quintets; (2) the electronic structures of triplet bent NFeN are more complicated than that of the others. Natural bonding orbital and Mulliken population data indicate that the Fe―N bond displays ionicity; (3) the most stable electronic state among all the states is 15A2 and the energies of 13B1, 13A2, 13B2, and 11A1 are similar, however, the most stable electronic state of linear NFeN is 3Δg. This reaction is endothermic because the energies of all the states are higher than those of the ground state Fe(a5D)+N2(X1Σg+) reactants while Fe(a5D)+2N(4S) is exothermic; (4) according to the calculated structure and vibrational characteristics the 13B1 state might be observed in the reported experiments; (5) compared with our previous results the structures of the FeN2 complexes are very different from that of the NFeN compound; (6) the Fe atom direct insertion reaction into the triple bonds of N2 is especially difficult because of the energy barriers in the reaction potential energy curves.

Key words: Density functional theory, Iron atom, Nitrogen molecule, NFeN