Study of static dipole polarizabilities, dipole moments, and chemical hardness for linear CH3-(CC)n-X (X=H, F, Cl, Br, and NO2 and n=1-4) molecules

Ab initio and density functional theory calculations have been performed to determine the dipole moment and static polarizabilities for CH3-(CC)n-X (X=H, F, CL, Br, NO2 and n=1-4) molecules. It is shown that a simple linear relation involving the aggregation number fits the polarizability results well with a correlation coefficient greater than 0.99 at ab initio and dft levels of calculations. The chemical hardness, global softness, and chemical potential have been calculated for the above molecules at HF and B3LYP levels of theory. It has been shown that good linear correlation between the dipole polarizabilities and cube root of static polarizabilities with dipole moments. Similarly, the softness parameters correlate well with the dipole polarizabilities and cube root of static polarizabilities. In addition to the above, we have calculated the cube root of static polarizabilities with the distortion of C-X bonds in CH3-(CC)-X (X=H, F, CL, Br, and NO2) molecules and tested the principle of maximum hardness.