Effect of optimised hybridization displacement charge on the description of molecular electrostatic potentials of some substituted acetaldehydes

Molecular electrostatic potential (MEP) maps of acetaldehyde, fluoroacetaldehyde, trifluoroacetaldehyde, hydroxyacetaldehyde and aminoacetaldehyde were studied usingab initio SCF wavefunctions with 6–31G** basis set as well as a recently developed and optimised new method in which a combination of Lowdin and hybridization displacement charges (HDC) at the MNDO level is used. An important point of this method is the distribution of electronic charges continuously and spherically in three dimensions, which helps reproduce most of the important features of the correspondingab initio MEP maps that cannot be achieved using point charges. Electrophilic reactivity of the molecules has been discussed using the MEP results.