The Structure and Chemical Bond of FOX-7: The AIM Analysis and Vibrational Normal Modes

Document Type : Research Note

Authors

1 Department of Chemistry, Faculty of Science, Shahr-e Rey Branch, Islamic Azad University, P.O. Box 18155-144 Tehran, I.R. IRAN

2 Malek-Ashtar University of Technology, Tehran, I.R. IRAN

Abstract

FOX-7 (1,1-diamino-2,2-dinitroethylene) recently is expected as a relatively new energetic material with high-performance and low sensitivity. The RHF and MP2 levels and DFT method with B3LYP functional with aug-cc-pVDZ basis set have been used for obtaining equilibrium geometry and Rho function (electron density distribution). By the aid of fundamental physical theorems implemented in the Quantum Theory of Atoms In Molecules (QTAIM), the structure, the physical nature of chemical bonds and all Bond Critical Points (BCPs) properties have been determined for FOX-7 at the mentioned theoretical levels. Existence of resonance due to "electron-withdrawing" nitro groups and "electron-donating" amine groups in ethene backbone and intra-molecular hydrogen bonding are shown with AIM analysis and then the resonance structures of FOX-7 are found. Also the calculated IR spectrum of FOX-7 is compared with the experimental IR spectrum. It is demonstrated that the mathematical properties of molecular graph derived from charge density analysis are in good correlation with that of the vibrational normal modes derived from ab initio computations.

Keywords

Main Subjects

References

[1] Dorsett H., Computational Studies of FOX-7, A New Insensitive Explosive, DSTO-TR-1054, Australia, (2000).
[2] Xu K.Z., Chang C.R., Song J.R., Zhao F.G., MA H.X., Lü X.G., Hu R.Z.,Preparation, Crystal Structure and Theoretical Calculation of G(FOX-7), Chinese J. Chem., 26, p. 495 (2008).
[3] Crawford M.J., Evers J., Göbel M., Klapötke T.M., Mayer P., Oehlinger G., Welch J.M., g-FOX-7: Structure of a High Energy Density Material Immediately Prior to Decomposition, Propellants, Explos., Pyrotech., 32, p. 478 (2007).
[4] Kempa P.B., Herrmann M., Temperature Resolved X-Ray Diffraction for the Investigation of the Phase Transitions of FOX-7, Part. Part. Syst. Charact., 22, p. 418 (2005).
[5] Politzer P., Concha M., Grice M., Murray J., Lane P., Habibollazadeh D., Computational Investigation of the Structures and Relative Stabilities of Amino/Nitro Derivatives of Ethylene, J. Mol. Struct. (Theochem), 452, p. 75 (1998).
[6] Chaoyang Z., Yuanjie S., Xiaodong Z., Haishan D., Xinfeng W., Computational Investigation on HEDM of Azoic and Azoxy Derivatives of  DAF, FOX-7, TATB, ANPZ and LLM-105, J. Mol. Struct. (Theochem), 728, p. 129 (2005).
[7] Meents A., Dittrich B., Johnas S.K.J., Thome V., Weckert E.F., Charge-density Studies of Energetic Materials: CL-20 and FOX-7, Acta Cryst., B64, p. 42 (2008).
[8] Becke A.D., Density-Functional Thermochemistry. III. The Role of Exact Exchange, J. Chem. Phys., 98, p. 5648 (1993).
[9] Lee C., Yang W., Parr R.G.,Development of the Colle-Salvetti Correlation-Energy Formula into a Functional of the Electron Density, Phys. Rev. B, 37, p. 785 (1988).
[10] Spartan'06. Deppmeier B.J., Driessen A.J., Hehre T.S., Hehre W.J., Johnson J.A., Klunzinger P.E., Leonard J.M., Ohlinger W.S., Pham I.N., Pietro W.J., Jianguo Yu., Wavefunction, Inc., Irvine, CA, (2006).
[11] A.A. Granovsky, http://classic.chem.msu.su/gran/ gamess/index.html, Schmidt M.W., Baldridge K.K., Boatz J.A., Elbert S.T., Gordon M.S., Jensen J.H., Koseki S., Matsunaga N., Nguyen K.A., Su S.J., Windus T.L., Together with Dupuis M., Montgomery J.A., General Atomic and Molecular Electronic Structure System, J. Comput. Chem., 14, p. 1347 (1993).
[12] Biegler-König F., Schönbohm J., Bayles D., AIM2000 - A Program to Analyze and Visualize Atoms in Molecules, J. Comp. Chem., 22, p. 545 (2001).
[13] Bader R.F.W., “Atoms in Molecules, A Quantum Theory; International Series of Monographs in Chemistry”, OxfordUniversityPress: Oxford, 22 (1990).
[14] Bader R.F.W.,A Quantum Theory of Molecular Structure and Its Applications, Chem. Rev., 91, p. 893 (1991).
[15] Bader R.F.W., The Quantum Mechanical Basis of Conceptual Chemistry, Monatshefte für Chemie, 136, p. 819 (2005).
[16] Bader R.F.W.,Everyman's Derivation of the Theory of Atoms in Molecules, J. Phys. Chem. A, 111, p. 7966 (2007).
[17] Popelier P.L.A., “Atoms in Molecules: An Introduction”, PrenticeHall,England, (2000).
[18] Bader R.F.W.,A Bond Path: A Universal Indicator of Bonded Interactions, J. Phys. Chem. A, 102, p. 7314 (1998).
[19] BemmU., Östmark H., 1,1-Diamino-2,2-Dinitroethylene: a Novel Energetic Material with Infinite Layers in Two Dimentions, Acta Cryst., C54, p. 1997 (1998).
[20] Gillespie R.G., Popelier P.L.A., “Chemical Bonding and Molecular Geometry”OxfordUniversityPress,New York, (2001).
[21] Levine I.N., “Molecular Spectroscopy” John Wiley & Sons, USA, p. 264 (1975).
[22] Pavia D.L., Lampman G.M., Kriz G.S., Vyvyan J.R., “Introduction to Spectroscopy” 4rd. Ed. Brooks/Cole, Cengage Learning, USA, p. 17 (2009).
Iranian Journal of Chemistry and Chemical Engineering
Volume 30, Issue 3 - Serial Number 59
September 2011
Pages 113-120

Files

Share

How to cite

Statistics