Determination of gas-phase nucleophilicities and electrophilicities using B•••HX bond critical point properties of AIM analysis

The values of nucleophilicity and electrophilicity have been established in gas phase for some nucleophiles (B = CH3CN, CO, H2O, H2S, HCN, N-2, NH3, PH3) and electrophiles (HX = HF, HCl, HBr, HCN HCF3) from properties of bond critical points of atoms in molecules (AIM) analysis. On the basis of the meaningful relationship, the recent method has been applied to electron density (rho), Laplacian of electron density (del(2)(rho)), and electronic kinetic energy density (G), of B-... HX bond critical point. AIM analysis has been performed on the obtained wave functions at MP2/6-311++G(d,p) level of theory. The correlation between averaged calculated values of nucleo-philicity (or electrophilicity), using different properties of B... HX bond critical points, and complexation energies (Delta E-comp) is satisfactory. The best correlation coefficient between nucleophilicity and Delta E-comp is related to rho values of bond critical points. But, the best correlation coefficient between electrophilicity and Delta E-comp is allied to del(2)(rho) and G values of bond critical points. (c) 2006 Elsevier B.V. All rights reserved.