A reduced electrophilicity for simple Lewis acids A involved in non-covalent interactions with Lewis bases B

Dissociation energies D-e for BMIDLINE HORIZONTAL ELLIPSISA = B + A can be written D-e = c ' NBEA, where N-B and E-A are the nucleophilicities and electrophilicities of the Lewis base B and the Lewis acid A, respectively. A reduced electrophilicity is defined Xi(A) = E-A/sigma(max), where sigma(max) is the maximum electrostatic surface potential on iso-surface of A, the atom directly involved in the non-covalent interaction. This definition is tested for halogen-bonded complexes BMIDLINE HORIZONTAL ELLIPSISYX, with Lewis bases B = N-2, CO, C2H2, C2H4, H2S, HCN H2O or NH3. D-e plotted against N-B for several series BMIDLINE HORIZONTAL ELLIPSISYX yields straight lines of gradient E-A. When D-e/sigma(max) is the ordinate, the straight lines conflate to a single line, gradient Xi(IX) = E-IX/sigma(max). Hydrogen-bonded complexes BMIDLINE HORIZONTAL ELLIPSISHX (X = F, Cl, Br, I), coinage-metal complexes BMIDLINE HORIZONTAL ELLIPSISMX (M = Cu, Ag, Au; X = F, Cl, Br, I), and alkali-metal bonded complexes BMIDLINE HORIZONTAL ELLIPSISMX (M = Li, Na: X = F, H, CH3) behave similarly. Xi(A) is an intrinsic property of the atom immediately involved in the non-covalent bond.

Automated summary

This paragraph discusses the relationship between dissociation energies D-e and nucleophilicities and electrophilicities, and defines reduced electrophilicity Xi(A). It also provides validation through examples of various complexes.