Predicting Reduction Potentials of 1,3,6-Triphenyl Fulvenes Using Molecular Electrostatic Potential Analysis of Substituent Effects

Abstract

The influence of mono- and multiple substituent effect on the reduction potential (E0) of 1,3,6-triphenyl fulvenes is investigated using B3LYP-SMD/6-3111G(d,p) level density functional theory. The molecular electrostatic potential (MESP) minimum at the fulvene p-system (Vmin) and the change in MESP at any of the fulvene carbon atoms (DVC) for both neutral and reduced forms are used as excellent measures of substituent effect from the para and meta positions of the 1,3 and 6-phenyl moieties. Substitution at 6-phenyl para position has led to significant change in E0 than any other positions. By applying the additivity rule of substituent effects, an equation in DVC is derived to predict E0 for multiply substituted fulvenes. Further, E0 is predicted for a set of 2000 hexa-substituted fulvene derivatives where the substituents and their positions in the system are chosen in a random way. The calculated E0 agreed very well with the experimental E0 reported by Godman et al. Predicting E0 solely by substituent effect offers a simple and powerful way to select suitable combinations of substituents on fulvene system for light harvesting applications. VC 2018 Wiley Periodicals, Inc.