Polarity of organometallic systems: Correlation analysis via substituent constants

Abstract

The mechanism of the substituent influence on polarity of organometallics is poorly understood. In this work, literature data on the substituent influence on dipole moments μ as a measure of the bond polarity for 43 narrow series of organometallic complexes have been considered using correlation analysis. Generally, the μ values for series studied, including complexes of organometallics with benzene, were first established to depend on the joint influence of the inductive, resonance, polarizability, and steric effects of substituents. The presence or absence of certain effects are dictated by the type of series. The polarizability effect (an electrostatic ion-dipole interaction) is caused by an excess charge appearing on indicator centre as a result of the complexation. The contribution of the polarizability effect ranges up to about 50%.