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Measures of unpaired electrons for large conjugated systems

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Abstract

It is shown that the numerical measure of effectively unpaired electrons N eff, proposed by Head-Gordon in 2003, is a particle-hole index: N eff is reduced to the average occupation of virtual particle-hole pairs. Specific π calculations of the N eff index provide a reasonable interpretation of the radicaloid character of the singlet ground state in complex conjugated systems. The results of the accurate π model (based on the total configuration interaction) and approximate approaches are compared. The coupled cluster method and various Hartree-Fock schemes (UHF and Löwdin EHF scheme) demonstrate an acceptable quantitative description of unpairing effects, UHF being favorable in simplicity of obtaining the measure of unpairing in megamolecules, such as graphene structures. The application of the known Yamaguchi index results in a rougher representation of the radical character of a system.

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References

  1. Y. Geerts, G. Klärner, and K. Müllen, Electronic Materials: The Oligomer Approach, Wiley-VCH, Weinheim (1998); K. P. Loh, Q. Bao, P. K. Ang, and J. Yang, J. Mater. Chem., 20, No. 12, 2277–2289 (2010).

    Google Scholar 

  2. K. Müllen and U. Scherf (eds.),in: Organic Light Emitting Devices, Synthesis, Properties and Applications, Wiley-VCH, Weinheim (2006).

    Google Scholar 

  3. K. Mullen and J. P. Rabe, Acc. Chem. Res., 41, No. 4, 511–520 (2008).

    Article  Google Scholar 

  4. W. Choi, I. Lahiri, R. Seelaboyina, and Y. S. Kang, Crit. Rev. Solid State, 35, No. 1, 52–71 (2010).

    Article  CAS  Google Scholar 

  5. K. M. Kadish and F. D’Souza (eds.), in: Handbook of Carbon Nano Materials. Volume 1. Synthesis and Supramolecular Systems, World Scientific Publishing, Singapore (2011).

    Google Scholar 

  6. A. L. Ivanovskii, Usp. Khim., 81, No. 7, 571–605 (2012).

    Article  Google Scholar 

  7. J. Hachmann, J. J. Dorando, M. Aviles, and G. K.-L. Chan, J. Chem. Phys., 127, No. 13, 134309-1–134309-9 (2007).

    Article  Google Scholar 

  8. E. F. Sheka, Int. J. Quant. Chem., 100, No. 4, 375–387 (2004).

    Article  CAS  Google Scholar 

  9. K. Yoneda, M. Nakano, K. Fukuda, and B. Champagne, J. Phys. Chem. Lett., 3, No. 22, 3338–3342 (2012).

    Article  CAS  Google Scholar 

  10. W. Mizukami, Y. Kurashige, and T. Yanai, J. Chem. Theor. Comp., 9, No. 1, 401–407 (2012).

    Article  Google Scholar 

  11. F. Plasser, H. Pašalic, M. H. Gerzabek, et al., Angew. Chem. Int. Ed., 52, No. 9, 2581–2584 (2013).

    Article  CAS  Google Scholar 

  12. K. Takatsuka, T. Fueno, and K. Yamaguchi, Theor. Chim. Acta, 48, No. 3, 175–183 (1978).

    Article  CAS  Google Scholar 

  13. D. Döhnert and J. Koutecky, J. Am. Chem. Soc., 102, No. 6, 1789–1796 (1980).

    Article  Google Scholar 

  14. V. N. Staroverov and E. R. Davidson, Chem. Phys. Lett., 330, Nos. 1–2, 161–168 (2000).

    Article  CAS  Google Scholar 

  15. R. C. Bochicchio, L. Lain, and A. Torre, Chem. Phys. Lett., 374, Nos. 5–6, 567–571 (2003); L. Lain, A. Torre, D. R. Alcoba, and R. C. Bochicchio, Chem. Phys. Lett., 476, Nos. 1–3, 101–103 (2009).

    Article  CAS  Google Scholar 

  16. M. Head-Gordon, Chem. Phys. Lett., 380, Nos. 3–4, 488/489 (2003).

    Google Scholar 

  17. A. V. Luzanov and O. A. Zhikol, Int. J. Quant. Chem., 104, No. 2, 167–180 (2005).

    Article  CAS  Google Scholar 

  18. A. V. Luzanov and O. V. Prezhdo, J. Chem. Phys., 124, No. 22, 224109-1–224109-16 (2006).

    Article  Google Scholar 

  19. A. V. Luzanov and O. V. Prezhdo, J. Chem. Phys., 125, No. 15, 154106-1–154106-14 (2006).

    Article  Google Scholar 

  20. C. Lambert, Angew. Chem. Int. Ed. Eng., 50, No. 8, 1756–1758 (2011).

    Article  CAS  Google Scholar 

  21. P. Karafiloglou and K. Kyriakidou, Int. J. Quant. Chem., 113, No. 13, 1775–1786 (2013).

    Article  CAS  Google Scholar 

  22. J. R. Dias, Mol. Phys., 111, No. 6, 735–751 (2013).

    Article  CAS  Google Scholar 

  23. A. A. Ovchinnikov, I. I. Ukrainskii, and G. V. Kventsel, Usp. Fiz. Nauk, 108, No. 1, 81–111 (1972); O. V. Yazyev, Acc. Chem. Res., 46, No. 10, 2319–2328 (2013).

    Article  CAS  Google Scholar 

  24. W. Kutzelnigg and V. H. Smith, Int. J. Quant. Chem., 2, No. 4, 531–552 (1968).

    Article  CAS  Google Scholar 

  25. A. V. Luzanov, Int. J. Quant. Chem., 113, No. 23, 2489–2505 (2013).

    Article  CAS  Google Scholar 

  26. I. A. Misurkin and A. A. Ovchinnikov, Pis’ma v ZHETF, 4, No. 7, 248–252 (1966).

    CAS  Google Scholar 

  27. E. F. Sheka and L. A. Chernozatonskii, J. Phys. Chem. C, 111, No. 29, 10771–10779 (2007); E. F. Sheka, Int. J. Quant. Chem., 112, No. 18, 3076–3090 (2012).

    Article  CAS  Google Scholar 

  28. A. T. Amos and G. G. Hall, Proc. R. Soc. (London) A, 263, No. 1315, 483–493 (1961).

    Article  Google Scholar 

  29. P.-O. Löwdin, Phys. Rev., 97, No. 12, 1509–1520 (1955).

    Article  Google Scholar 

  30. I. Mayer, Adv. Quant. Chem., 12, 189–262 (1980).

    Article  CAS  Google Scholar 

  31. M. M. Mestechkin, G. E. Vaiman, V. Climo, and I. Tin’o, Extended Hartree-Fock Method and its Application to Molecules [in Russian], Naukova dumka, Kiev (1983).

    Google Scholar 

  32. A. V. Luzanov and V. V. Ivanov, Theor. Èkserim. Khim., 26, No. 4, 385–396 (1990).

    CAS  Google Scholar 

  33. I. Shavitt and R. J. Bartlett, Many-Body Methods in Chemistry and Physics: MBPT and Coupled-Cluster Theory, Cambridge University Press, Cambridge (2009).

    Book  Google Scholar 

  34. A. V. Luzanov and Yu. F. Pedash, Theor. Èkserim. Khim., 21, No. 4, 385–391 (1985).

    CAS  Google Scholar 

  35. D. Crawford and H. F. Schaefer, Rev. Comput. Chem., 14, 133–136 (2000).

    Google Scholar 

  36. C. D. Sherrill, A. I. Krylov, E. F. C. Byrd, and M. Head-Gordon, J. Chem. Phys., 109, No. 11, 4171–4181 (1998).

    Article  CAS  Google Scholar 

  37. K. Yankowski and K. Rubiniec, Mol. Phys., 100, No. 11, 1741–1754 (2002).

    Article  Google Scholar 

  38. P. Pulay and T. P. Hamilton, J. Chem. Phys., 88, No. 8, 4926–4933 (1988).

    Article  CAS  Google Scholar 

  39. I. Murata, Pure & Appl. Chem., 65, No. 1, 97–103 (1993).

    Article  CAS  Google Scholar 

  40. V. N. Staroverov and E. R. Davidson, J. Am. Chem. Soc., 122, No. 1, 186/187 (2000).

    Article  Google Scholar 

  41. J. Fernández-Rossier and J. J. Palacios, Phys. Rev. Lett., 99, No. 17, 177204-1–177204-4 (2007).

    Article  Google Scholar 

  42. M. R. Philpott and Y. Kawazoe, J. Chem. Phys., 134, No. 12, 124706-1–124706-9 (2011).

    Article  Google Scholar 

  43. A. S. Barnard and I. K. Snook, Modelling Simul. Mater. Sci. Eng., 19, No. 5, 054001 (2011).

    Article  Google Scholar 

  44. X. Jia, J. Campos-Delgado, M. Terrones, V. Meunier, et al., Nanoscale, 3, No. 1, 86–95 (2011).

    Article  CAS  Google Scholar 

  45. M. Acik and Y. J. Chabal, J. Appl. Phys., 50, 070101-1–070101-16 (2011).

    Article  Google Scholar 

  46. R. Zan, Q. M. Ramasse, U. Bangert, and K. S. Novoselov, Nano Lett., 12, No. 8, 3936–3940 (2012).

    Article  CAS  Google Scholar 

  47. Y. Liu, A. Dobrinsky, and B. I. Yakobson, Phys. Rev. Lett., 105, No. 23, 235502-1–235502-4 (2010).

    Article  Google Scholar 

  48. A. V. Luzanov, J. Struct. Chem., 54, No. 1, 1–9 (2013).

    Article  CAS  Google Scholar 

  49. P. Szakács, Á. Szabados, and P. R. Surján, Chem. Phys. Lett., 498, Nos. 4–6, 292–295 (2010).

    Article  Google Scholar 

  50. V. V. Ivanov, I. P. Kisil, and A. V. Luzanov, J. Sruct. Chem., 37, No. 4, 537–543 (1996).

    Article  Google Scholar 

Download references

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Correspondence to A. V. Luzanov.

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Original Russian Text © 2014 A. V. Luzanov.

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Translated from Zhurnal Strukturnoi Khimii, Vol. 55, No. 5 pp. 845–854, September–October, 2014.

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Luzanov, A.V. Measures of unpaired electrons for large conjugated systems. J Struct Chem 55, 799–808 (2014). https://doi.org/10.1134/S0022476614050011

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