Linear and Nonlinear Optical Properties of Triphenylamine–Indandione Chromophores: Theoretical Study of the Structure–Function Relationship under the Combined Action of Substituent and Symmetry Change

Abstract

Linear and nonlinear optical properties of experimentally synthesized triphenylamine-indandione chromophores were investigated by time-dependent density functional theory calculations. The absorption and emission spectra, as well as the static and dynamic first hyperpolarizabilities related to the combined effect of substituent introduction and symmetry breaking, were discussed in detail. Theoretical analysis indicated the uniting of indandione acceptor group(s) with a precursor (triphenylamine, TriPhA), with the molecular symmetry destroyed simultaneously, leads to an obvious change in both the peak position and intensity of the linear spectra. The same process can also substantially magnify the molecular first hyperpolarizabilities. The triphenylamine-indandione molecules exhibit efficiencies in static first hyperpolarizability relative to that of the electron-donating TriPhA component and the electron-accepting indandione moiety. The optical nonlinearity would be further expanded under the influence of a resonance effect induced by appropriate excitation. Incident light with a wavelength nearly two times the one-photon absorption is likely to cause a greater frequency dispersion response. In particular, the first hyperpolarizabilities of the title compounds can be enlarged by about 3.2 times on average by resonance enhancement at a fundamental wavelength of 1064 nm.

Spectroscopic and theoretical optical properties of indoleninyl‐substituted dibenzotetraaza[14]annulenes

“…Also, the decrease of the HOMO‐LUMO energy gap from the effect of the substituent groups might contribute to a higher β tot value. [ 48,49 ] Interestingly, 6 has a larger β tot value compared to experimental values of various substituted metal free phthalocyanines ( β = 25.1‐44.9 × 10 −30 esu). [ 50 ] Hence, 6 could be useful for NLO applications.…”

Effects of External Field Wavelength and Solvation on the Photophysical Property and Optical Nonlinearity of 1,3-Thiazolium-5-Thiolates Mesoionic Compound

“…Therefore, the field of optical materials has been exploring how to develop new compounds with tunable photophysical properties or enhanced (hyper)polarizabilities for a long time. [4][5][6] So far, researchers have successfully recognized a variety of molecules with exciting optical properties, including inorganic complexes, [7][8][9] organic molecules, [10][11][12][13] metal clusters, 14,15 doped polarizable electrides, 16,17 and even macrocyclic compounds with special topology, 6,18,19 and applied some of them into practice. Among them, the conjugated organic chromophores with electron donating and electron accepting groups at both ends were one of the most popular optical units, partially due to their convenient structural tailoring.…”

Theoretical Framework of 1,3-Thiazolium-5-Thiolates Mesoionic Compounds: Exploring the Nature of Photophysical Property and Molecular Nonlinearity

“…24 However, in general, it is difficult to reveal the nature and origin of the optical properties of molecules by experimental observation alone, and meanwhile, most of the previous theoretical studies on such molecules only focused on the numerical value of their first-order hyperpolarizability. 19,24 Therefore, in view of the fact that the optical properties of mesoionic compounds can be controlled through structural tailoring and continuing our consistent interest in the molecules with abnormal structures, [25][26][27][28][29] we have conducted detailed studies on the photophysical and nonlinear properties of these experimental molecules.…”