Zu Fragen der Polarität

Die Methode der Linearkombination der Wechselwirkungskräfte (LKWW)

Abstract

It is proposed that an organic molecule can be characterised by a «property vector» of the following form:

E =  ( D P   H_a/H_d E_a/E_d L_a/L_d)  [sqrt(energy/mole)] (1)

The terms of this vector show the ability of the molecule to attract other organic molecules: D: by dispersion forces and P: by the inhomogeneity of its electrical field. The remaining terms symbolise properties in which forces between two molecules exist only if one of them is an acceptor, the other a donor: H_a/H_d: interaction by displacement of a nucleus of the donor towards the acceptor («hydrogen bridge»), E_a/E_d: by displacement of «one» electron in one molecule towards the other («charge transfer») and L_a/L_d: Lewis acid-base type interaction.
All terms beside D should be small and in any case not greatly exceed the magnitude of sqrt(RT). In this case a linear combination of the interaction forces (LCID) is admissible as approximation to calculate the resulting force as shown by the equations (2), (3), (4) and (5). Note that P is defined to represent an additional effect to D furthermore H, E and L represent additional effects over D + P.
Existing polarity scales are discussed in the light of the method of LCIF in a qualitative manner.