The ten chemically transparent dinitronaphthalene isomers and their radical anions

Abstract

Dinitroaromatics have a long scientific history, with very recent (e.g. S.F. Nelsen, M.N. Weaver and J.P. Telo, J. Phys. Chem. A 113, 7730 (2009)) important contributions. The electron affinities for the nitrobenzene, dinitrobenzene and dinitronaphthalene isomers are predicted. The ten obvious structures of neutral dinitronaphthalene (DNN) have been predicted from theory. These ten isomers span an energetic range of 14 kcal mol⁻¹, with the global minimum 2,7 structure lying only 0.3 kcal mol⁻¹ below 2,6. The analogous ten isomers of the DNN radical anion have also been optimized and display a broader range of 25 kcal mol⁻¹. Among the anions 2,6-DNN lies below the next most favourable isomer (2,7) by 6.5 kcal mol⁻¹. The three known adiabatic electron affinities are predicted to be 1.12 (nitrobenzene), 1.91 (ortho-dinitrobenzene), 1.94 (meta-dinitrobenzene), and 2.32 eV (para-dinitrobenzene), values that range from 0.12 to 0.32 eV above the most recent experiments. We conclude that the experimental vertical detachment energy (VDE) of 3.10 eV for para-dinitrobenzene is too high by a surprising 0.85 eV. For the dinitronaphthalenes the following adiabatic electron affinities are estimated; 1.70 (1,2-dinitronaphtalene), 1.81 (1,3), 2.12 (1,4), 1.85 (1,5), 1.78 (1,6), 1.86 (1,7), 1.47 (1,8), 1.53 (2,3), 1.99 (2,6), and 1.69 eV (2,7).

Keywords:

• electron affinity
• dinitrobenzene
• dinitronaphthlane

Acknowledgements

This research was supported by the U.S. National Science Foundation, Grant CHE-074986. U.B. thanks the Scientific and Technological Research Council of Turkey (TUBITAK) for supporting his scientific study at the University of Georgia. The authors thank Aaron Lu, Katie Compaan, and Dr. Yaoming Xie for many helpful discussions. We also thank Professor J. Mathias Weber (University of Colorado) for valuable email correspondence.

Notes

Note

Supporting information available online

Total energies and ZPVE values for neutral species and anions are reported in the Supplementary Material.