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 betwee n the static molecular dipole moment m0, the static polarizability alp ha 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 ini tio 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 hybridizati on of the atoms. For equilibrium structures the electronegativity diff erences determined in this work are found to be within the range spann ed by other scales.