Nucleophilicities of Lewis Bases B and Electrophilicities of Lewis Acids A Determined from the Dissociation Energies of Complexes B⋯A Involving Hydrogen Bonds, Tetrel Bonds, Pnictogen Bonds, Chalcogen Bonds and Halogen Bonds

• Published in: Molecules (Basel, Switzerland) Switzerland), 2017-10, Vol.22 (10), p.1786
• Main Authors: Alkorta, Ibon, Legon, Anthony C
• Format: Article
• Language: English
• Subjects: ab initio calculations; Acids; binary complexes; Carbon dioxide; Chalcogen bonds; Chalcogens - chemistry; Chemical bonds; dissociation energies; electrophilicity; Energy of dissociation; Free energy; geometry; Halogens - chemistry; Heat of formation; Hydrogen - chemistry; Hydrogen Bonding; Hydrogen bonds; Hydrogen sulfide; Lewis Acids - chemistry; Lewis Bases - chemistry; Models, Molecular; Nitrous oxide; noncovalent bonds; nucleophilicity; Quantum Theory; Selenium dioxide; Sulfur dioxide; Thermodynamics
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules22101786

It is shown that the dissociation energy D e for the process B⋯A = B + A for 250 complexes B⋯A composed of 11 Lewis bases B (N₂, CO, HC≡CH, CH₂=CH₂, C₃H₆, PH₃, H₂S, HCN, H₂O, H₂CO and NH₃) and 23 Lewis acids (HF, HCl, HBr, HC≡CH, HCN, H₂O, F₂, Cl₂, Br₂, ClF, BrCl, H₃SiF, H₃GeF, F₂CO, CO₂, N₂O, NO₂F, PH₂F, AsH₂F, SO₂, SeO₂, SF₂, and SeF₂) can be represented to good approximation by means of the equation D e = c ' N B E A , in which N B is a numerical nucleophilicity assigned to B, E A is a numerical electrophilicity assigned to A, and c ' is a constant, conveniently chosen to have the value 1.00 kJ mol here. The 250 complexes were chosen to cover a wide range of non-covalent interaction types, namely: (1) the hydrogen bond; (2) the halogen bond; (3) the tetrel bond; (4) the pnictogen bond; and (5) the chalcogen bond. Since there is no evidence that one group of non-covalent interaction was fitted any better than the others, it appears the equation is equally valid for all the interactions considered and that the values of N B and E A so determined define properties of the individual molecules. The values of N B and E A can be used to predict the dissociation energies of a wide range of binary complexes B⋯A with reasonable accuracy.