Theoretical Analysis of the Electronic Structure and Bonding Stability of the TCNE Dimer Dianion (TCNE)22-

Journal of the American Chemical Society

Volumn 125, Issue 51, 2003, Pages 16089-16096

  Jakowski, Jacek ^a   Simons, Jack ^a  

^a UNIVERSITY OF UTAH   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

COUNTERIONS; SOLVENT STABILIZATION;

CHEMICAL BONDS; DISSOCIATION; ELECTRON ABSORPTION; ELECTRON TRANSITIONS; ELECTRONIC STRUCTURE; NEGATIVE IONS; SPECTRUM ANALYSIS; THERMODYNAMIC STABILITY;

ORGANIC COMPOUNDS;

ANION; DIMER; TETRACYANOETHYLENE;

ABSORPTION SPECTROSCOPY; ARTICLE; CHEMICAL BOND; CHEMICAL STRUCTURE; GEOMETRY; MOLECULAR STABILITY; SIMULATION; SOLVATION; STRUCTURE ANALYSIS; THEORY; THERMODYNAMICS; THERMOSTABILITY;

EID: 0346364989     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja030240p     Document Type: Article

References (25)

1. (a) Novoa, J. J.; Lafuente, P.; Del Sesto, R. E.; Miller, J. S. Angew. Chem., Int. Ed. 2001, 40, 2540-2545.
2. (b) Del Sesto, R. E.; Miller, J. S.; Lafuente, P.; Novoa, J. J. Chem. Eur. J. 2002, 8, 4894-4908.
3. - anions. The four π electrons are not what is forming the inter-TCNE bond; rather, it is the two π* electrons.
4. 1 configuration. However, the fact that the findings presented later in this paper, based upon the former electronic configuration, are consistent with the observed experimental data (including the UV-vis spectra) suggest the closed-shell rather than the singlet open-shell configuration is more likely.
5. Very recently, another group has examined the same dimer dianion's UV-vis spectra as well as the thermodynamics involved in the ion-pairing process: Lü, J.; Roscokha, S. V.; Kochi, J. K. J. Am. Chem. Soc. 2003, 125, 12161-12171.
6. For example, as discussed later, the bases we employ produce dianion-to-anion energy gaps (i.e., vertical electron detachment energies) in good agreement with those found in the following reference where the larger basis mentioned earlier was used: Zakrzewski, V. G.; Dolgounitcheva, O.; Ortiz, J. V. J. Chem. Phys. 1996, 105, 5872.
7. van Duijneveldt, F. B.; van Duijneveldt-van de Rijdt, J. G. C. M.; van Lenthe, J. H. Chem. Rev. 1994, 94, 1873-1885.
8. Jeziorski. B.; Szalewicz, K. Intermolecular Interactions by Perturbation Theory. In The Encyclopedia of Computational Chemistry; von Rague Schleyer, P., Allinger, N. L., Clark, T., Gastaiger, J., Kollman, P. A., Schaefer. H. F., Schreiner, P. A., Eds.; Wiley: Chichester, 1998.
9. Frisch, M. J.; Trucks, G. W.; Schlegel, H., B.; et al. Gaussian 98, Revision A7: Gaussian, Inc.: Pittsburgh, PA, 1998.
10. Tomasi, J.; Persico, M. Chem. Rev. 2027-2094.
11. We could not use methyl-tetrahydorfuran because the Gaussian 98 program we employ does not contain explicit solvation parameters for this solvent, whereas it does for THF.
12. See, for example, p 327 of An Introduction to Statistical Thermodynamics; Hill, T. L., Ed.; Addison-Wesley: Reading, MA, 1960.
13. For these calculations, we used the more recent Gaussian 03 suite of codes (Frisch, M. J.: Trucks, G. W.; Schlegel, H. B.; et al. Gaussian 03; Gaussian, Inc.: Pittsburgh, PA, 2003.).
14. We observed negligible changes in the geometry of the anion when BSSE corrections were performed, and we found the BSSE energy corrections for the dimer monoanion to be very near to those of the dimer dianion.
15. 2/R). See, for example: Senekowitsch, J.; Oneil, S. V.; Wemer, H.-J.; Knowles, P. J. J. Phys. B 1991, 24, 1529-1538, and references therein.
16. This calculation is not meant to produce an accurate representation of the dimer dianion curve either within the solids of ref I or in THF solution. It is intended to simply suggest that it is reasonable that Coulomb repulsion is the primary reason for the dianion not displaying a minimum in its potential curve.
17. 2-, so this does not mutate the dianion into the monoanion. Instead, it produces a potential that can more tightly bind the electrons to the nuclear framework.
18. Simons, J. J. Chem. Phys. 1981, 75, 2465-2467.
19. Frey, R.; Simons, J. J. Chem. Phys. 1986, 84, 4462-4469.
20. Hazi, A. U.; Taylor, H. S. Phys. Rev. A 1970, 1, 1109.
21. e energy of -3.3 eV, and the R = 6 Å Coulomb repulsion (to extrapolate the energy to R = ∞) of 0.32 eV. That is, the energy difference is [0.32 + 3.4] - 3.3 = 0.42 eV.
22. -
23. -1, and we do not include any solvent dielectric screening because it was included in the calculations leading to the 0.4 eV energy difference obtained from Figure 6.
24. - monoanion.
25. These calculations were performed by altering the α and β spin-orbital occupations of the ground state dianion, using these altered occupations to initiate a UHF calculation, after which MP2 corrections were computed. We should note that we found correlation contributions to the excitation energies of these states to be large. As noted elsewhere in this text, if these states are examined at the UHF or singly excited configuration interaction (C1S) level, one does not achieve very reasonable values of the excitation energies.