Bond Lengths and Atomic Radii in Compounds EX3 (E = N, P, As, Sb; X = F, Cl, Br, I)

Correlations between bond lengths d and the first ionization potentials of atoms and molecules are established on the basis of experimental data. Functional dependences are obtained for the series of compounds EX3 (E = N, P, As, Sb; X = F, Cl, Br, I) when X or E are substituted. The difference between dependences with varied E or X are explained by the differing effects on electron pairs of ion E3-. A way of estimating the values of ion radii R-E for the elements N, P, As, and Sb is proposed. Interdependences of the values of radii of ions, their dipole moments, and refractions are discussed. The effect substituents X have on the values of radii R-E is shown. The values of radii R-E(3-) are evaluated for spherically symmetric ions. Linear dependences of radii R-E(3-) and ionization potentials of the corresponding ions E3- and atoms of inert gases on their effective charges are established.