A RELATIONSHIP BETWEEN THE MOLECULAR POLARIZABILITY, MOLECULAR DIPOLE-MOMENT AND ATOMIC ELECTRONEGATIVITIES IN AB AND ABN MOLECULES

Electroneptivity equalization considerations applied to diatomics and AB(n) molecules of C(nv) symmetry lead to a simple relationship between the static molecular dipole moment m0, the static polarizability alpha along the principal axis and the electroneptivity difference DELTA(CHI) between atoms A and B. The relationship is alpha = m0 R/DELTA(CHI), where R is the bond length (or height in the case of AB(n)). Ab initio calculations are used to assess this equation. For single bonds it is found that DELTA(CHI) is remarkably constant over a range of bond lengths, or moderately changing at most. However, DELTA(CHI) is found to be sensitive to valence coordinates that can modify the hybridization of the atoms. For equilibrium structures the electronegativity differences determined in this work are found to be within the range spanned by other scales.