Paweł Szlachcic

Silesian University of Technology, Gleiwitz, Silesian Voivodeship, Poland

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Publications (23)22.26 Total impact

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    ABSTRACT: Three fluoro-substituted pyrazoloquinoline derivatives have been placed in polymer matrices: polycarbonate, poly(methyl methacrylate) and polystyrene. Absorption, excitation and time-resolved fluorescence spectra have been recorded and luminescence lifetime of the optically active composites has been determined. Influence of the dielectric environment the optical properties of the chromophores are discussed. Experimental data and conclusions are supported with (TD)DFT calculations.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 10/2013; 120C:494-498. · 1.98 Impact Factor
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    Paweł Szlachcic, Tomasz Seidler, Katarzyna Stadnicka
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    ABSTRACT: The crystal structure of the title compound, C22H26S4·2I2, contains two centrosymmetric molecules of 1,2,4,5-bis{8′,11′-dithia[4.3.3]propella(3′,4′)}benzene, and four I2 molecules in the unit cell of space group P21/c. The cyclohexene rings adopt boat conformation, whereas tetrahydrothiophene rings have envelope conformation. The iodine molecules are linked to one type of the sulphur atoms of the propellane molecule by a charge-transfer bond, with S⋯I distance of 2.7844(12) and I–I = 2.8153(5) Å. The second type of symmetrically independent sulphur atoms are engaged in a weak interaction of C–H⋯S type with the H⋯S distance of 3.09(1) Å. The geometry optimisation of the crystal structure at the B3LYP level with MIDI! basis set gave good agreement with the experimental data (S⋯I distance of 2.754 and I–I = 2.923 Å). NBO analysis for the complex showed that the S⋯I interaction is due to charge transfer from the lone pair on the sulphur to the vacant σ* orbital of the I2 acceptor.
    Journal of Molecular Structure 02/2013; 1033:162–170. · 1.40 Impact Factor
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    ABSTRACT: Three fluoro- substituted pyrazoloquinoline derivatives have been placed in polymer matrices: polycarbonate, poly(methyl methacrylate) and polystyrene. Absorption, excitation and time-resolved fluorescence spectra have been recorded and luminescence lifetime of the optically active composites has been determined. Influence of the dielectric environment the optical properties of the chromophores are discussed. Experimental data and conclusions are supported with (TD)DFT calculations.
    Spectrochimica Acta Part A Molecular Spectroscopy 01/2013;
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    Paweł Szlachcic, Katarzyna Stadnicka
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    ABSTRACT: The 1H-pyrazolo-[3,4-b]quinoline (PQ) core of the title mol-ecule, C(23)H(14)F(3)N(3), is aromatic and essentially planar (r.m.s. deviation = 0.015 Å) and the two phenyl substituents at positions 1 and 3 are twisted relative to this fragment by 29.74 (7) and 25.63 (7)°, respectively. In the crystal, mol-ecules are arranged along the b axis into stacks via π-π inter-actions, with an inter-planar distance of the PQ core of 3.489 (4) Å.
    Acta Crystallographica Section E Structure Reports Online 07/2012; 68(Pt 7):o2287. · 0.35 Impact Factor
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    ABSTRACT: The molecular and crystal structures of two derivatives containing 8,11-dioxa[4.3.3]propellane moiety: 8,11-dioxa[3,4-(4′-methylbenzo)]-[4.3.3]propellane and 8,11-dioxa[3,4-(4′-tert-butylbenzo)]-[4.3.3]propellane, were determined and compared with those found for 1,2,4,5-bis{8′,11′-dioxa[4.3.3]propella(3′,4′)}benzene. The discussion of the most stable conformation of cyclohexene and tetrahydrofurane rings for isolated 8,11-dioxa(3,4-benzo)]-[4.3.3]propellane molecule was made using the DFT calculations. The results were compared with those performed for tetraline and 2,2,3,3-tetramethyltetraline. 8,11-Dioxa[3,4-(4′-methylbenzo)]-[4.3.3]propellane is important as a reference compound because the unsubstituted 8,11-dioxa(3,4-benzo)-[4.3.3]propellane cannot be obtained in the form of crystalline phase suitable for X-ray diffraction. 1H NMR spectroscopic analysis showed that the methyl group does not induce expected splitting of the appropriate signals, observed in the case of tert-butyl derivative.
    Journal of Molecular Structure 03/2012; 1012:87–96. · 1.40 Impact Factor
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    ABSTRACT: Theoretical simulations of UV-vis spectra for organic chromophores: 3-(4-fluorophenyl)-1,4-diphenyl-, 1-(4-fluorophenyl)-3,4-diphenyl- and 4-(4-fluorophenyl)-1,3-diphenyl-1H-pyrazolo[3,4-b]quinoline. Density Functional Theory 6-31G calculations were performed. The molecular geometry and UV-vis spectra were simulated with the time-dependent DFT calculations. Influence of number of occupied and excited states on the behavior of the spectra is explored. To further improve the calculations a Polarizable Continuum Model (PCM) was employed to simulate the influence of solvent polarity. It was used in both geometry optimization and spectra simulation. An attempt to find a correlation between the values of dipole moments and the spectral shifts was performed. The results were compared with experiment.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 09/2010; 77(1):130-4. · 1.98 Impact Factor
  • Paweł Szlachcic, Bozena Jarosz, Katarzyna Stadnicka
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    ABSTRACT: In the structure of the title compound, C(29)H(18)F(3)N(3), belonging to the space group P6(5) (or P6(1)), three symmetry-independent molecules are arranged in two chains, with two molecules alternating along the 3(2) axes, whereas the remaining molecule forms a chain along [0001] due to the 6(5) screw axis. The conformation of each of the molecules is stabilized by an intramolecular C-H...N hydrogen bond, with C...N distances in the range 2.964 (6)-3.069 (5) A at room temperature (293 K) and 2.943 (4)-3.084 (4) A at low temperature (100 K). One molecule has its -CF(3) group ordered even at 293 K, which can be explained only by considering its involvement in two weak intermolecular C-H...F interactions, with C...F distances in the range 3.084 (6)-3.302 (5) A at 293 K and 3.070 (3)-3.196 (3) A at 100 K, and also a C-F...N interaction, with a C...N distance of 3.823 (5) A at 293 K and 3.722 (4) A at 100 K. The trifluoromethyl groups in the two remaining molecules are disordered at 293 K, whereas at 100 K the continuous (dynamic) positional disorder of one of the -CF(3) groups (of the molecule forming the chain along [0001]) is totally eliminated while the -CF(3) group disorder remains for the third molecule.
    Acta crystallographica. Section C, Crystal structure communications 09/2010; 66(Pt 9):o488-92. · 0.78 Impact Factor
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    ABSTRACT: The results of experimental research and quantum-chemical simulations of the absorption spectra of 1-(4-fluorophenyl)-3,4-diphenyl, 3-(4-fluorophenyl)-1,4-diphenyl, and 4-(4-fluorophenyl)-1,3-diphenyl-pyrazolo[3,4-b] quinoline are presented. Although the fluorine atom is located on different phenyl rings in these molecules, the absorption spectra do not differ significantly. Semi-empirical AM1, PM3 and RM1 methods, as well as ab initio ADF code-based calculations were used to optimize geometry, calculate the infrared and visible spectra of the afore mentioned compounds and analyze the molecular orbitals schemes. The results of calculations are in good agreement with the experimental data. It was also demonstrated that the positions of the fluorescence maxima depend significantly on the solvent (contrary to the absorption spectra), in which the molecules are embedded, which allows for manipulating with fluorescence properties of the synthesized molecules by changing the solvent.
    Chemical Physics. 05/2010; 370(1-3):194-200.
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    ABSTRACT: The results of experimental research and quantum-chemical simulations of the absorption spectra of 1-(4-fluorophenyl)-3,4-diphenyl, 3-(4-fluorophenyl)-1,4-diphenyl, and 4-(4-fluorophenyl)-1,3-diphenyl-pyrazolo[3,4-b] quinoline are presented. Although the fluorine atom is located on different phenyl rings in these molecules, the absorption spectra do not differ significantly. Semi-empirical AM1, PM3 and RM1 methods, as well as ab initio ADF code-based calculations were used to optimize geometry, calculate the infrared and visible spectra of the afore mentioned compounds and analyze the molecular orbitals schemes. The results of calculations are in good agreement with the experimental data. It was also demonstrated that the positions of the fluorescence maxima depend significantly on the solvent (contrary to the absorption spectra), in which the molecules are embedded, which allows for manipulating with fluorescence properties of the synthesized molecules by changing the solvent.
    Chemical Physics. 05/2010; 370(1-3):194-200.
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    ABSTRACT: Absorption, photo- and electroluminescence spectra of some trityl substituted 1H-pyrazolo[3,4-b]quinolines derivatives (methyl- and phenyl substituted) and fabrication of the single layered organic light emitting diodes are reported. The bulky trityl substituent was introduced to prevent aggregation and crystallization of the dopant in polymer matrix. Role of ground state dipole moments in the observed red Stokes shift, electroluminescent features and photocarrier transport is explored. The maximally achieved brightness about 50Cd/m(2) is observed in the spectral range extending from 443nm up to 462nm. The voltage threshold was varied from 7.8V up to 10V. The brightness-current dependences show an existence of at least two types of carrier injections.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2010; 75(5):1501-5. · 1.98 Impact Factor
  • Paweł Szlachcic, Katarzyna Stadnicka
    Acta Crystallographica Section E-structure Reports Online - ACTA CRYSTALLOGR E-STRUCT REP. 01/2010; 66(3).
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    Paweł Szlachcic, Andrzej Danel, Katarzyna Stadnicka
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    ABSTRACT: In the title mol-ecule, C(23)H(17)N(3), the phenyl substituents at positions 1 and 4 are twisted relative to the central core by 27.09 (5) and 66.62 (4)°, respectively. In the crystal, mol-ecules are assembled into centrosymmetric dimers via π-π stacking inter-actions between the 1H-pyrazolo-[3,4-b]quinoline -units, with an inter-planar distance of 3.601 (2) Å and by weak inter-molecular C-H⋯N inter-actions.
    Acta Crystallographica Section E Structure Reports Online 01/2010; 66(Pt 11):o3009. · 0.35 Impact Factor
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    ABSTRACT: An influence of phenoxy groups for the luminescent and electroluminescent properties of spiro-compounds with pyrazolo [3,4-b] quinoline structure (fluorophore) chromophore has been studied. All the compounds exhibit strong fluorescence in solution and in solid state as well. The prepared compounds were used as dopant chromophore in PVK polymer matrices for electroluminescent (EL) and light-emitting diode (LED) devices with configuration ITO/PEDOT-PSS/PVK/PQ/Ca/Al. Role of the bathochromic shifts and solvent polarity in absorption and photoluminescent maxima is considered. Relation between the number of pyrazoloquinoline chromophore and presence of phenyl group on the fluorescence spectra is explored. Polarizability of the particular pyrazoloquinoline compounds on the solvatochromic effects is investigated. Possible ways of enhancement of the brightness in the light-emitting properties of the mentioned chromophore are discussed.
    Journal of Luminescence 01/2010; · 2.14 Impact Factor
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    Paweł Szlachcic, Katarzyna Stadnicka
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    ABSTRACT: In the title compound, C(28)H(18)FN(3)·0.5C(6)H(6), the 1H-pyrazolo[3,4-b]quinoline core is almost planar (r.m.s = 0.0371 Å, maximum deviation = 0.0571 Å) and aromatic. The solvent benzene mol-ecules are located around inversion centres. In the crystal, mol-ecules related by centres of symmetry form dimers, with distances of 3.932 (3) Å between best planes through the fused core due to π⋯π stacking. The phenyl substituents at positions 1, 3 and 4, are twisted away from the core, making dihedral angles of 29.66 (7), 44.59 (7) and 67.94 (6)°, respectively.
    Acta Crystallographica Section E Structure Reports Online 01/2010; 66(Pt 3):o575. · 0.35 Impact Factor
  • Paweł Szlachcic, Bożena Jarosz, Katarzyna Stadnicka
    Acta Crystallographica Section C-crystal Structure Communications - ACTA CRYSTALLOGR C-CRYST STR. 01/2010; 66(9).
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    ABSTRACT: The purpose of this work was synthesis of a new copolymer consisting of poly(N-vinylcarbazole) and pyrazoloquinoline based dye, suitable to provide electroluminescence in the wavelength range corresponding to the blue. The obtained material was tested in a simple, single layer electroluminescent device. It were studied both its electronic and optical performances. It was found that the maximum of electroluminescence spectrum can be tuned within the wavelength of 450 nm and 490 nm (what reads in terms of colours as the blue and the cyan) by simple variation of the dye content.
    IEEE Conference Proceedings. 3rd ICTON Mediterranean Winter Conference,2009IEEE Conference Proceedings. 3rd ICTON Mediterranean Winter Conference,2009; 01/2009
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    ABSTRACT: Optically and electric-field induced linear electrooptics effect (PILEOE) was discovered during investigations of the 3-(4-Nitrophenyl)-6-N,N-diphenylamine-1-phenyl-1H-pyrazolo[3,4-b]quinoline and stilbene chromophores embedded into polymer PMMA matrices. The PILEOE was discovered in the quinoline and stilbene derivatives incorporated into the polymer PMMA matrices. one can see that the PILEOE coefficients achieve their maxima after 130–140s of the bicolor photo-treatment with simultaneous applied electric field. For the both polarization geometries corresponding to two different electrode-laser polarizations the maximal value of the PILEOE coefficient is achieved for the two pyrazoloquinoline molecule and lower Pockels effect is achieved for the stilbene molecule. The behavior is changed drastically for cross-polarized (electrode-pump polarizations). In this case the effect is very low for pyrazoloquinoline chromophore (A and B) and is substantially larger for the C chromophore. Moreover, the absolute value of the achieved PILEOE is almost the same for co- and cross-polarized experimental geometry. The performed molecular geometry optimization and quantum chemical simulation have shown that the observed features are different for the two class of the chromophore and by different influence of external bicolor light on the photo-structural changes. For the quinoline crucial role belongs to co-planar nitrogen atoms, which are very sensitive to the geometry of photoinduced electrooptics effect. For the case of the stilbene role of the cis–trans isomerization is not so crucial and the corresponding anisotropy is almost absent contrary to the generally adopted model. For all the investigated chromophore maximal values of the PILEOE effect is smaller in the direction perpendicular the pump polarization (cross-polarized geometry) compared to the parallel (co-polarized) ones. The anisotropy is substantially larger for the quinoline chromophore compared to the stilbene ones. Analysis of photoinduced optical absorption and IR spectra of quinoline show principal role of the nitrogen-induced co-planarity inside the aromatic groups in the observed PILEOE anisotropy.
    Journal of Materials Science Materials in Electronics 04/2008; 19(5):434-441. · 1.49 Impact Factor
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    ABSTRACT: The fluorescence behaviour of some newdyes based on the pyrazolo[3,4-b]quinoline (PQ) ring has been investigated. Itwas found that introduction of electron withdrawing and electron donating groups into pyrazolo[3,4-b]quinoline molecule causes an increase of the ground and excited state dipole moments but more important is introduction of the N,N-dimethylamine group directly into the pyrazolo[3,4-b]quinoline skeleton. Further introduction of the cyano groups in the peripheral phenyl rings brings about only minor changes in the transition dipole moments (absorption and fluorescence). Such compounds exhibit a CT fluorescence. The fluorescence of these compounds was investigated in terms of the radiative charge transfer transition to obtain the charge transfer parameters such as the energy gap between the charge transfer and the ground states, solvent reorganization energies and internal reorganization energy. The magnitude of these parameters was discussed in terms of a modern electron transfer theory and the parameters were used to calculate the rate constants for non-radiative CT transition.
    Journal of Photochemistry and Photobiology A Chemistry 10/2007; · 2.42 Impact Factor
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    ABSTRACT: The fluorescence behaviour of some new dyes based on the pyrazolo[3,4-b]quinoline (PQ) ring has been investigated. It was found that introduction of electron withdrawing and electron donating groups into pyrazolo[3,4-b]quinoline molecule causes an increase of the ground and excited state dipole moments but more important is introduction of the N,N-dimethylamine group directly into the pyrazolo[3,4-b]quinoline skeleton. Further introduction of the cyano groups in the peripheral phenyl rings brings about only minor changes in the transition dipole moments (absorption and fluorescence). Such compounds exhibit a CT fluorescence. The fluorescence of these compounds was investigated in terms of the radiative charge transfer transition to obtain the charge transfer parameters such as the energy gap between the charge transfer and the ground states, solvent reorganization energies and internal reorganization energy. The magnitude of these parameters was discussed in terms of a modern electron transfer theory and the parameters were used to calculate the rate constants for non-radiative CT transition.
    Journal of Photochemistry and Photobiology A: Chemistry 01/2007; 187:78-86.
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    ABSTRACT: The fluorescence behaviour of some new dyes based on the pyrazolo[3,4-b]quinoline (PQ) ring has been investigated. It was found that introduction of electron withdrawing and electron donating groups into pyrazolo[3,4-b]quinoline molecule causes an increase of the ground and excited state dipole moments but more important is introduction of the N,N-dimethylamine group directly into the pyrazolo[3,4-b]quinoline skeleton. Further introduction of the cyano groups in the peripheral phenyl rings brings about only minor changes in the transition dipole moments (absorption and fluorescence). Such compounds exhibit a CT fluorescence. The fluorescence of these compounds was investigated in terms of the radiative charge transfer transition to obtain the charge transfer parameters such as the energy gap between the charge transfer and the ground states, solvent reorganization energies and internal reorganization energy. The magnitude of these parameters was discussed in terms of a modern electron transfer theory and the parameters were used to calculate the rate constants for non-radiative CT transition.
    Journal of Photochemistry and Photobiology A-chemistry - J PHOTOCHEM PHOTOBIOL A-CHEM. 01/2007; 187(1):78-86.