Molecular Electrostatics for Exploring Complexes of Carbonyl Compounds and Hydrogen Fluoride

Abstract

The negative-valued molecular electrostatic potential (MESP) minima (V min) observed in the substituted carbonyl molecules are found to be a sensitive measure for the analysis of the electronic charge perturbations due to the substituents. MESP topography of eight monosubstituted aliphatic carbonyl molecules (HCOR: R = H, F, Cl, CN, OH, SH, NH2, CH3, CF3, NO2) [following Bobadova-Parvanova, P.; Galabov, B. J. Phys. Chem. A 1998, 102, 1815] is carried out at the HF-SCF/6-31G** level for assessing this scheme. The V min values are seen to clearly reflect the changes due to the electron donating/withdrawing substituents. The electrostatic potential for intermolecular complexation (EPIC) model is used for predicting the possible hydrogen-bonded structures of the carbonyl molecules with the hydrogen fluoride. These complexes are further optimized at the HF-SCF/6-31G** level of theory. An excellent linear correlation is obtained with EPIC energy and the corresponding optimized interaction energy of the complex. Total correction to the ab initio SCF interaction energy due to basis set superposition error and zero-point energy is found to be about 40% of the SCF interaction energy. The HF molecule binds from the nonsubstituted sides of the HCOR molecules for RH, F, Cl, CN, and CF3. On the other hand, it is seen to bind from the substituted side for ROH, SH, NH2, and CH3. The effect of substitution on the charge distribution and on hydrogen bonding is discussed.

Electrostatics for probing lone pairs and their interactions

“…Here the largest eigenvalues are in the range 0.0262 to 0.1619 au. The distance d 1 of V min from the lone‐pair‐bearing atom is useful for interpreting the likely distance of interaction between the lone‐pair‐bearing atom and the electron deficient atom in another molecule . As may be noticed from Table , the distances d 1 of sp 3 ‐P and sp 3 ‐S are large compared to those for sp 3 ‐N and sp 3 ‐O which is obviously due to the larger size of the valence orbital in the case of third‐row elements compared to the corresponding second‐row ones.…”

“…WWW.C-CHEM.ORG atom in another molecule. [6,53,54] As may be noticed from Table 1, the distances d 1 of sp 3 -P and sp 3 -S are large compared to those for sp 3 -N and sp 3 -O which is obviously due to the larger size of the valence orbital in the case of third-row elements compared to the corresponding second-row ones.…”

Structuring and destructuring effects along a pathway toward formation of zwitterionic glycine···(H2O)2 complex: many body analysis of clusters and molecular electrostatic potential investigations

“…These negative‐valued isosurfaces indicate the sites of attack by a positively charged end favorable for the formation of a weak bond. A detailed discussion on MESP complementarity and its application to weakly interacting complexes will be found elsewhere, in the studies by Gadre et al41, 42, 46–52…”

Charge doping effect on σ-π conjugated copolymers

“…Molecular electrostatic potentials [44][45][46] were computed to examine the doping effect on the charge density distributions. Molecular electrostatic potentials of all structures were calculated at the BH&HLYP/6-31G* optimized geometries and plotted using gOpenMol 2.32 [47].…”