Structure–reactivity relationships for aromatic molecules: electrostatic potentials at nuclei and electrophile affinity indices

Abstract

Recent advances have been achieved in the quantitative description of the reactivity of aromatic compounds in terms of simple parameters derived from theoretical computations. The first part of this review surveys the use of electrostatic potentials at nuclei (EPN) in characterizing the reactivity of substituted aromatic compounds when the reaction center is situated outside the aromatic ring. The application of EPN for several typical reactions of substituted aromatic systems is described in detail. The performance of alternative reactivity descriptors, such as theoretical atomic charges, the Parr electrophilicity index, and the experimental Hammett constants, is considered as well. The second part of this review discusses the recently proposed electrophile affinity construct for quantifying reactivity and regiospecificity for the most typical reaction of arenes: electrophilic aromatic substitution. The characterization of reactivity of aromatic molecules in terms of proton affinities and arene nucleophilicity indices is surveyed briefly. C 2012 John Wiley & Sons, Ltd.

Effects of structural variations on the hydrogen bond pairing between adenine derivatives and thymine

“…Since the atoms in the vicinity of N1 and N6 atoms in adenine remain the same throughout the investigated series (Scheme 1), it can be considered that the shifts of V Y (Y = N1, H6) upon the distant structural variations (at position C8) are dominated by electron density variations near atoms Y. Numerous successful application of EPN as a reactivity index for hydrogen bonding and chemical reactivity confirm the credibility of this hypothesis [53][54][55][56][57][58][59][60][61][62][63][64][65]. Figure 1 illustrates key geometrical parameters of some optimized complexes.…”

“…Z A is the charge of nucleus A at position R A , and ρ(r) is the electron density func-tion. Following the original findings [53][54][55][56][57] that EPN values define quantitatively the ability of molecules to form hydrogen bonds, the EPN index was extensively applied in describing both hydrogen bonding and chemical reactivity of various molecular systems [58][59][60][61][62][63][64][65]. In a recent review, we surveyed the application of EPN in quantifying various molecular properties of aromatic systems [62].…”

Theoretical vs. Experimental Ir Frequency Shifts Upon Π- Hydrogen Bonding: Complexes of Substituted Phenols With Hexamethylbenzene

“…EPN was first introduced by Wilson in 1962 [41]. In a number of studies from our laboratory, we have established that EPN is a remarkably accurate descriptor of the abilities of specific atomic centers in molecules to form hydrogen bonds [42][43][44][45][46][47] and also in quantifying chemical reactivity [48][49][50][51]. In later years, EPN values have been successfully employed by other authors in examining reactivity trends [52][53][54][55][56][57][58][59][60].…”

Surface enhanced Raman scattering investigation of two novel piperazine carbodithioic acids adsorbed on Ag and ZnO nanoparticles

“…24,46 The MEP surfaces of the optimized PZCDT/ PZbCDT ions and their Ag (n¼1-4) complexes are illustrated in Fig. MEPS are completely related to the electron density and a very useful descriptor for determining the sites for electrophilic attack and nucleophilic reaction as well as structure-reactivity relationship of the molecules.…”