Molecular-Orbital Theory of Diamagnetism. II. Calculation of Pascal Constants for Some Noncyclic Molecules

Abstract

The general formulas for atomic contributions to diamagnetic susceptibilities derived in part I are used to calculate Pascal-type constants for some simple molecules containing hydrogen, carbon, nitrogen, oxygen, and fluorine. For noncyclic saturated molecules, the theory reproduces the relative values of empirical atomic contributions fairly satisfactorily, although absolute numerical agreement is poor. For unsaturated groups, the theory provides an interpretation of the constitutive corrections required in the Pascal scheme. Considerable positive corrections are calculated for the carbon—carbon double bond and the carbonyl group, but not for the carbon—carbon triple bond. This is in agreement with the empirical rules. The theory also makes a number of predictions about diamagnetic anisotropies.