Linear and Nonlinear Optical Properties of Azobenzene Derivatives Modified with an (Amino)naphthalene Moiety

Abstract

The design of two-photon absorbing azobenzene (AB) derivatives has received much attention; however, the two-photon absorption (2PA) properties of bis-conjugated azobenzene systems are relatively less explored. Here, we present the synthesis of six azobenzene derivatives and three bis-azobenzenes substituted (or not) at para position(s) with one or two amino group(s). Their linear and nonlinear absorption properties are studied experimentally and theoretically. The switching behavior and thermal stability of the Z -isomer are studied for unsubstituted mono- ( 1a , 2a ) and bis-azobenzene ( 3a ) compounds, showing that when the length of the π system increases, the half-life of the Z -isomer decreases. Moreover, along with the increase of π-conjugation, the photochromic characteristics are impaired and the photostationary state (PSS) related to E – Z photoisomerization is composed of 89% of the Z -isomer for 2a and 26% of the Z -isomer for 3a . Importantly, the 2PA cross-section increases almost five-fold on extending the π-conjugation ( 2a vs 3a ) and by about one order of magnitude when comparing two systems: the unsubstituted π-electron one ( 2a , 3a ) with D-π-D ( 2c , 3c ). This work clarifies the contribution of π-conjugation and substituent effects to the linear and nonlinear optical properties of mono- and bis-azobenzene compounds based on the experimental and theoretical approaches.

Hybrids of Polyynes and Azo Dyes: Synthesis, Characterization, and Two-Photon Absorption

“…The cross section of 2PA of RC 8 R is even higher than 2PA organometallic platinum end-capped octatetrayne measured at similar wavelengths . At the same time, 2PA of compound RC 8 R might be regarded as rather strong if some of the best diazobenzenes (entries 10–12) are considered. − …”

Azo Appended Modified Lawsone Derived Ru‐Systems with Multi‐Redox Entities. Competitive Electronic Form and the Question of Azo Reduction

“…Further, under the specialized circumstances, uptake of additional two electrons leads to the cleavage of the −N−N− bond to the imido form (Scheme 1). [8] Metallated azobenzene is also recently shown to extend modulation of the NLO (non‐linear optical) response with special reference to the free ligand [9] …”

“…[8] Metallated azobenzene is also recently shown to extend modulation of the NLO (non-linear optical) response with special reference to the free ligand. [9] On the other hand, environmentally hazardous waste produces out of the extensive usage of industrially significant azo dyes demands its facile degradation. Reduction of azocontaining compounds is thus considered as the first step forward in the direction of the degradation process.…”

Light-responsive organic polaritons from first principles

“…13 Dudek et al elucidated the contribution of π-conjugation and substituent effects to the linear and nonlinear optical properties of mono- and bis-azobenzene compounds based on experimental and theoretical approaches. 14 For porphyrin molecules, Palummo et al theoretically investigated the electronic and optical properties of free base porphyrin and free base tetraphenyl porphyrin molecules (H 2 TPP) by using density functional theory and many-body perturbation theory. 4 Lopes et al demonstrated that endocyclic substituents can make asymmetric Q-bands of free base porphyrins relatively symmetric.…”