Conceptual and Computational Density Functional Theory in the
Study of Chemical Reactivity
Frank De Proft
Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel (VUB), Faculteit
Wetenschappen en Bio-ingenieurswetenschappen, Pleinlaan 2, B-1050 Brussels,
Belgium.
e-mail : fdeprof@vub.ac.be
Density Functional Theory (DFT)1 is a branch of quantum chemistry which uses
the electron density (r) as the basis of all the information of an atomic or molecular
. Next to the well-established computational
advantages of DFT, it is the source for a series of chemical concepts, readily used by
chemists but previously only empirically defined. Examples are the electronegativity,
hardness and softness and Fukui's frontier molecular orbital reactivity index.
Moreover, within this theory, theoretical justification was provided for several
principles, such as Sanderson's principle of electronegativity equalization and
Pearson's Hard and Soft Acids and Bases and Maximum Hardness principles. This
area of DFT was termed by R. G. Parr as "conceptual DFT".1,2
In this contribution, we will present some recent examples of the use of
computational and conceptual DFT in the study of chemical reactivity, concentrating
both on applications in organic and inorganic chemistry. The most relevant DFTbased reactivity indices and principles will first be outlined. In a second part, we
present the construction of a DFT based scale of radical electrophilicity and
nucleophilicity.3 Next, we will discuss the use of this concept in the establishment of a
companion intrinsic radical stability scale.4 These concepts will then be used in the
study of divalent Ge and Sn compounds, and in the interpretation of their possible
complexation with aromatic -clouds.5 Following this part, attention will be devoted to
the so-called linear response function as a measure for electron delocalization and its
relationship with the concept of aromaticity will be established. 6 This aromaticity
concepts also plays a vital role in the recovering of the famous Woodward-Hoffmann
rules for pericyclic reactions in conceptual DFT, which will then be discussed using
both the concept of the initial hardness response and the so-called dual descriptor.7
In a final part, we discuss a recent application in the area of catalysis focussing on
the use of DFT based reactivity indices to study the support effect in supported
vanadium oxide catalysts.8
References
[1] R. G. Parr and W. Yang, Density Functional Theory of Atoms and Molecules,
Oxford University Press, New York, 1989.
[2] (a) R. G. Parr and W. Yang, Ann. Rev. Phys. Chem. 46, 701 (1995). (b) H.
Chermette, J. Comput. Chem. 20, 129 (1999). (c) P. Geerlings, F. De Proft and W.
Langenaeker, Chem. Rev. 103, 1793 (2003). (d) P. W. Ayers, J. S. M. Anderson
and L. J. Bartolotti, Int. J. Quant. Chem. 101, 520 (2005).
[3] F. De Vleeschouwer, V. Van Speybroeck, M. Waroquier, P. Geerlings and F. De
Proft, Org. Lett. 9, 2721 (2007).
[4] F. De Vleeschouwer, V. Van Speybroeck, M. Waroquier, P. Geerlings and F. De
Proft, J. Org. Chem. 73, 9109 (2008).
[5] L. Broeckaert, P. Geerlings, A. Růžička, R. Willem and F. De Proft, submitted.
[6] (a) N. Sablon, F. De Proft and P. Geerlings, J. Phys. Chem. Lett. 1, 1228 (2010).
(b) N. Sablon, F. De Proft and P. Geerlings, Chem. Phys. Lett. 498, 192 (2010). (c)
N. Sablon, F. De Proft, P. W. Ayers and P. Geerlings J. Chem. Theory Comput. 6,
3671 (2010).
[7] (a) F. De Proft, P. W. Ayers, S. Fias and P. Geerlings, J. Chem. Phys. 125, 21410
(2006). (b) P.W. Ayers, C. Morell, F. De Proft and P. Geerlings, Chem. Eur. J. 13,
8214 (2007). (c) F. De Proft, P.K. Chattaraj, P.W. Ayers, M. Torrent-Sucarrat, M.
Elango, V. Subramanian, S. Giri and P. Geerlings, J. Chem. Theory Comput. 4,
595 (2008). (d) P. Jaque, J. V. Correa, A. Toro-Labbé, F. De Proft and P.
Geerlings, Can. J. Chem. 88, 858 (2010).
[8] T. Fievez, B. M. Weckhuysen, P. Geerlings and F. De Proft, J. Phys. Chem. C
113, 19905 (2009).