Acta Phys. -Chim. Sin. ›› 1999, Vol. 15 ›› Issue (06): 495-499.doi: 10.3866/PKU.WHXB19990603

• ARTICLE • Previous Articles     Next Articles

Calculation of (CH2)2N和(CH3)2NH+ by Density Functional Theory

Chen Bo-Zhen, Huang Ming-Bao, Yan Da-Yu   

  1. Graduate School at Beijing,University of Science and Technology of China,Beijing 100039
  • Received:1998-08-25 Revised:1998-11-02 Published:1999-06-15
  • Contact: Chen Bo-Zhen

Abstract:

 Conformations and hyperfine structures of the dimethylamino radical (CH_3)_2N and its protonated cation radical (CH3)2NH+ were studied at the UB3LYP/6-31G(d p) level, and isotropic hyperfine coupling constants on the α-proton, β-proton, and nitrogen nucleus (A(Hα), A(Hβ) and A(N)) of the two radicals were calculated using two DFT (UB3LYP and UB3PW91) methods and ab initio UHF and UMP2 (FULL) methods. The results of calculation indicate that the barriers to methyl group rotation in the two radicals are very low, being 0.46 and 2. 6 kJ•mol-1 for (CH3)2NH+ and (CH3)2N, respectively. The A (Hα), A(Hβ) and A(N) values in the two radicals are predicted by the UB3LYP/6-31G(d, p) and UB3PW91/6-31G(d, p) calculations in excellent agreement with experimental ones, and the UMP2 (FULL) /6-31G (d, p ) values are in quite good agreement with the experimental values.

Key words: Radical, Conformation, Hyperfine structure, Density functional theory