Browsing by Author "Szukalski, Adam"

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All-Optical Switching and Two-States Light-Controlled Coherent-Incoherent Random Lasing in a Thiophene-Based Donor-Acceptor System
(2018-07-05)
Szukalski, Adam
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Ayadi, Awatef
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Haupa, Karolina
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El-Ghayoury, Abdelkrim
;
Sahraoui, Bouchta
We describe herein the synthesis and characterization of a thiophene-based donor-acceptor system, namely (E)-2-(4-nitrostyryl)-5-phenylthiophene (Th-pNO(2)), which was prepared under Horner-Wadsworth-Emmons conditions. The UV/Vis absorption bands, including the intramolecular charge transfer (ICT) band, were fully assigned using DFT and TD-DFT computations. The results of both efficient third-order nonlinear optical properties and light-amplification phenomena are presented. Investigations of photoinduced birefringence (PIB) in optical Kerr effect (OKE) experiments showed a great potential for this particular compound as an efficient, fully reversible, and fast optical switch. Time constants for the observed trans-cis-trans molecular transitions are in the range of microseconds and give a competitive experimental result for the well-known and exploited azobenzene derivatives. Random lasing (RL) investigations confirmed that this organic system is potentially useful to achieve strong light enhancement, observed as a multimode lasing action. Both RL and OKE measurements indicate that this material is a representative of thiophene derivatives, which can be utilized to fabricate fast all-optical switches or random lasers (light amplifiers).
Lasing Properties Activation by Constitutional Isomerism of an Electron-Accepting Group
(2020-06-25)
Szukalski, Adam
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Haupa, Karolina A.
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Janczak, Jan
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Przybyl, Bartosz
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Sznitko, Lech
Materials engineering plays a pivotal role considering its manifold applications, i.e., in medicine as individualized drug carriers or in advanced technologies such as optoelectronic devices and others. Recently, increasing interest in the pyrazoline derivatives family of compounds was noticed. In this paper, we report on the constitutional isomerism influence on photophysical properties of low molecular, push-pull type of pyrazole-based organic chromophores. Particularly, we show the ability of optical properties tailoring by changing the substitution of phenyl ring extended by effective electron-accepting moiety in ortho and para positions. Such a structural change in molecule results in a shift of photoluminescence spectra as well as the activation or deactivation of gain mechanism for multimode laser emission. In order to confirm ground state molecular structures for both isomers we performed time-dependent DFT calculations in a solvent environment. In addition, structural analysis of spontaneously grown single crystals was carried out using X-ray spectroscopy. The above-mentioned studies allowed us to define the isomer's molecular geometries and charge distribution in excited and ground states and to distinguish the significant differences in crystallographic structures. Combined experimental and theoretical research have resulted in a hypothesis of the molecular mechanism standing behind observed differences in optical properties of both isomers. Importantly, such an approach can be useful for materials engineering, allowing us to predict the features of novel materials for optoelectronics and photonics.
Low-Molecular Push Pull Pyrazoline Derivatives: Solvatochromic Effect and Theoretical Insights into Dye-based Molecular Engineering
(2018-10-04)
Haupa, Karolina Anna
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Szukalski, Adam
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Mysliwiec, Jaroslaw
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應用化學系
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應用化學系分子科學碩博班
Intermolecular interactions between dyes and solvents are essential in understanding a number of phenomena. In this contribution, we focused on similarities and differences between two molecules belonging to the same pyrazoline derivatives group: the small and rigid- 3-(1,1-dicyanoethenyl)-1-phenyl-4,5-dihydro-1H-pyrazole (DCNP) molecule and the quite long and 3 flexible one of (4-(2-(1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)vinyl)-benzylidene) malononitrile (PY-PhdiCN). We experimentally show and use theoretical calculations to prove that extension of pi-connector significantly changes the electrostatic potential distribution, which results in delocalization of negative charge along the whole donor group and increases potential surface of interaction with solvent molecules giving large spectral shifts. We also show that pyrazoline derivatives are very effective and sensitive solvent indicators with long-time stability.
TTF based donor-pi-acceptor dyads synthesized for NLO applications
(2017-03)
Ayadi, Awatef
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Szukalski, Adam
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El-Ghayoury, Abdelkrim
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Haupa, Karolina
;
Zouari, Nabil
Two new TTF-pi-acceptor dyads that contain p-nitrophenyl group as acceptor and bis-(styryl)benzene system as an efficient pi-conjugated bridge have been synthesized by multistep synthetic procedure and their electrochemical behavior has been studied by cyclic voltammetry (CV). The occurrence of an intramolecular charge transfer (ICT) in these molecules has been evidenced by UV-Visible electronic absorption spectroscopy and these studies were completed by DFT calculations in both gas phase and in solution. The nonlinear optical parameters obtained via SHG and THG measurements are described and indicate that these materials are valuable candidates for the construction of optoelectronic and photonic devices. The Optical Kerr Effect measurements indicate that these materials exhibit a great potential in the field of optical switchers construction, where the material\'s photoresponse time is a crucial parameter. (C) 2016 Elsevier Ltd. All rights reserved.