Chemphyschem : a European journal of chemical physics and physical chemistry | 2021
Composing NLO chromophore as a puzzle: electrochemistry-based approach to the design and effectiveness.
Abstract
A series D-π-A, D-π-D -π-A, D-π-A -π-A nonlinear optical chromophores with vinylene π-electron bridges or bridges with π-deficient/π-excessive heterocyclic moieties along with the corresponding precursors D-vinylene, D-π-D , D -π-A, D-π-A and A -π-A are obtained and studied both experimentally and computationally. The effect of heterocycle in π-electron bridge on the oxidation/reduction potentials and the energy gaps, ΔE el , is specially investigated. The properties of the D-π-A (D )-π-A chromophores are shown to correlate with those of building blocks: oxidation potential is determined by the D-vinylene, and reduction potential is determined by A (D )-π-A truncated compounds. The contribution of the acceptor to the oxidation potential of chromophores in comparison with those of the precursors was estimated and analyzed in terms of electronic communication between the end groups. A good correlation between the ΔE el and the chromophores first hyperpolarizability is revealed.