Examples



mdbootstrap.com



 
Статья
2020

Role of Fullerene–Nitrogen Complexes of Alkali Metals in C60-Catalyzed Nitrogen Fixation


A. F. ShestakovA. F. Shestakov
Российский журнал физической химии А
https://doi.org/10.1134/S0036024420050209
Abstract / Full Text

The key stage of the activation of a nitrogen molecule upon the catalytic reduction of N2 to ammonia in an aqueous medium in the presence of a complex of C60 with γ-cyclodextrin, in the range of potentials of C60 reduction to the dianione, is considered using the PBE density functional. The possible role of the ionic associates (C60)2−(M+)n (n = 1, 2) that inevitably form upon the reduction of C60, due to the presence of a background electrolyte containing alkali metal ions M+, is also studied. It is found that in complexes (C60MN2), the bond energy of N2 is 7.0, 5.3, and 4.7 kcal/mol for M = Li, Na, and K, respectively. The M–N distances are 0.2 Å shorter than in cationic complexes (MN2)+, due to electron density transfer from the ligand \({\text{C}}_{{60}}^{{2 - }}\) to the nitrogen molecule. As a result, the N2 molecule is protonated upon the interaction of the neutral associates (C60Li2N2) with a hydroxonium ion. At low energies of activation, the adduct (LiC60LiN2H+ · H2O) transforms to the primary protonated product with a N–C bond and a gain in energy of 10 kcal/mol. Its subsequent reduction to two NH3 molecules encounters no thermodynamic obstacles.

Author information
  • Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432, Chernogolovka, Moscow oblast, RussiaA. F. Shestakov
  • Department of Physical and Chemical Engineering, Lomonosov Moscow State University, 119991, Moscow, RussiaA. F. Shestakov
References
  1. Y. Nishibayashi, M. Saito, S. Uemura, et al., Nature (London, U.K.) 428, 279 (2004).
  2. L. Pospısil, J. Bulıckova, M. Hromadova, et al., Chem. Commun., 2270 (2007).
  3. A. F. Shestakov, Russ. J. Gen. Chem. 78, 811 (2008). https://doi.org/10.1134/S1070363208040403
  4. N. Yu. Trifonov and A. F. Shestakov, Butler. Soobshch. 43 (8), 147 (2015).
  5. Y. Zhang, D. Ye, X. Gao, W. Liu, and F. Li, Fullerenes, Nanotubes, Carbon Nanostruct. 15, 317 (2007).
  6. J. P. Perdew, K. Burke, and M. Ernzerhof, Phys. Rev. Lett. 77, 3865 (1996).
  7. W. J. Stevens, H. Basch, and M. Krauss, J. Chem. Phys. 81, 6026 (1984).
  8. D. N. Laikov, Chem. Phys. Lett. 416, 116 (2005).
  9. F. L. Hirshfeld, Theor. Chim. Acta 44, 129 (1977).
  10. R. G. Parr, P. W. Ayers, and R. F. Nalewajski, J. Phys. Chem. A 109, 3957 (2005). https://doi.org/10.1021/jp0404596
  11. J. W. Ho, R. J. Drake, and D. W. Stephan, J. Am. Chem. Soc. 115, 3792 (1993).
  12. T. A. Bazhenova, A. V. Kulikov, A. F. Shestakov, et al., J. Am. Chem. Soc. 117, 12176 (1995).