Nonlinear optical performance of poled liquid crystalline azo-dyes confined in SiO<sub>2</sub>sonogel films

Torres-Zúñiga, V.; Morales–Saavedra, Omar G.; Rivera, Ernesto; Flores-Flores, José O.; Bañuelos, J.G.; Ortega-Martı́nez, R.

doi:10.1080/09500340903521843

Cited by 5 publications

(3 citation statements)

References 33 publications

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“…13,14 Among the large variety of ABs, push-pull azobenzenes (pp-ABs) are attractive because of their intense colour, strong dipolar character and good non-linear optical properties. [15][16][17][18][19] ABs are grouped according to the energy spacing between their two lowest singlet excited states. 1 In the unsubstituted AB, the S 2 pp* state is well above the S 1 np* state (B1 eV) and both states can be directly populated upon optical excitation.…”

Section: Introductionmentioning

confidence: 99%

Influence of the hydrogen-bond interactions on the excited-state dynamics of a push–pull azobenzene dye: the case of Methyl Orange

Nançoz

Licari

Beckwith

et al. 2018

Phys. Chem. Chem. Phys.

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The excited-state dynamics of the push-pull azobenzene Methyl Orange (MO) were investigated in several solvents and water/glycerol mixtures using a combination of ultrafast time-resolved fluorescence and transient absorption in both the UV-visible and the IR regions, as well as quantum chemical calculations. Optical excitation of MO in its trans form results in the population of the S ππ* state and is followed by internal conversion to the S nπ* state in ∼50 fs. The population of this state decays on the sub-picosecond timescale by both internal conversion to the trans ground state and isomerisation to the cis ground state. Finally, the cis form converts thermally to the trans form on a timescale ranging from less than 50 ms to several minutes. Significant differences depending on the hydrogen-bond donor strength of the solvents, quantified by the Kamlet Taft parameter α, were observed: compared to the other solvents, in highly protic solvents (α > 1), (i) the viscosity dependence of the S state lifetime is less pronounced, (ii) the S state lifetime is shorter by a factor of ≈1.5 for the same viscosity, (iii) the trans-to-cis photoisomerisation efficiency is smaller, and (iv) the thermal cis-to-trans isomerisation is faster by a factor of ≥10. These differences are explained in terms of hydrogen-bond interactions between the solvent and the azo nitrogen atoms of MO, which not only change the nature of the S state but also have an impact on the shape of ground- and excited-state potentials, and, thus, affect the deactivation pathways from the excited state.

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Section: Introductionmentioning

confidence: 99%

Influence of the hydrogen-bond interactions on the excited-state dynamics of a push–pull azobenzene dye: the case of Methyl Orange

Nançoz

Licari

Beckwith

et al. 2018

Phys. Chem. Chem. Phys.

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“…For example, morphological and optical properties including nonlinear optical performance have been studied for azo-polymer-based sonogel hybrid composites and azo-dye confined SiO 2 sonogel films [20,21]. The sonogel host systems have provided thermal and mechanical stability protecting the activate chromophores and preserving their optical properties.…”

Section: Introductionmentioning

confidence: 98%

Photochemistry of azobenzene in sol–gel systems

Ide

Ozama

Matsui

2011

Journal of Non-Crystalline Solids

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“…The isomerizable azobenzenes dispersed in silica matrix have been reported by several groups. [47][48][49][50][51] The reported conventional counterparts include thin lms [48][49][50][51][52] or sonogels. 51 The highest doping ratio (12 wt%, at least several orders of magnitude larger than conventional azobenzene-SiO 2 composites) and the homogeneous and transparent ionogel glass of azobenzene related COP obtained in this study could have some unique advantages.…”

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confidence: 99%

Three-arm star compounds composed of 1,3,5-tri(azobenzeneethynyl)benzene cores and flexible PEO arms: synthesis, optical functions, hybrid Ormosil gel glasses

Xie

Deng

et al. 2013

J. Mater. Chem. C

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A three-arm star rod-coil block conjugated compound composed of 1,3,5-tri(azobenzeneethynyl)benzene core and flexible poly(ethylene oxide) arms was synthesized. For comparison, two others with the same core but different end groups were also prepared. The compounds show thermotropic discotic liquid crystalline phase behavior and properties of optical limiting and photo-induced trans-cis isomerization.The star-shaped compound with poly(ethylene oxide) arms can be homogeneously dispersed into Ormosil gel glass monoliths up to 12 wt% without any compatibilizer. The glasses are mechanically stable and highly transparent in the visible and near IR region. The nonlinear optical and optical limiting properties of the gel glasses are comparable or superior to those of the corresponding solutions. The photochromic property of the azobenzene units can be maintained in the gel glass state.

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Nonlinear optical performance of poled liquid crystalline azo-dyes confined in SiO₂sonogel films

Cited by 5 publications

References 33 publications

Influence of the hydrogen-bond interactions on the excited-state dynamics of a push–pull azobenzene dye: the case of Methyl Orange

Influence of the hydrogen-bond interactions on the excited-state dynamics of a push–pull azobenzene dye: the case of Methyl Orange

Photochemistry of azobenzene in sol–gel systems

Three-arm star compounds composed of 1,3,5-tri(azobenzeneethynyl)benzene cores and flexible PEO arms: synthesis, optical functions, hybrid Ormosil gel glasses

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Nonlinear optical performance of poled liquid crystalline azo-dyes confined in SiO2sonogel films

Cited by 5 publications

References 33 publications

Influence of the hydrogen-bond interactions on the excited-state dynamics of a push–pull azobenzene dye: the case of Methyl Orange

Influence of the hydrogen-bond interactions on the excited-state dynamics of a push–pull azobenzene dye: the case of Methyl Orange

Photochemistry of azobenzene in sol–gel systems

Three-arm star compounds composed of 1,3,5-tri(azobenzeneethynyl)benzene cores and flexible PEO arms: synthesis, optical functions, hybrid Ormosil gel glasses

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Product

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Nonlinear optical performance of poled liquid crystalline azo-dyes confined in SiO₂sonogel films