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Wrocław, Poland

Deperasinska I.,Polish Academy of Sciences | Szemik-Hojniak A.,Wroclaw University | Osowska K.,Wroclaw University | Rode M.F.,Polish Academy of Sciences | And 5 more authors.
Journal of Photochemistry and Photobiology A: Chemistry | Year: 2011

The Cadiot-Chodkiewicz type C2-elongation of p-tolylacetylene followed by dimerization of the resulted diyne p-CH3C 6H4(C≡C)2TMS (1) gave thermally stable octatetrayne p-CH3C6H4(C≡C) 4-p-C6H4CH3 (2) as light yellow powder in 75% yield. Compound 2 was characterized by spectroscopic methods and X-ray crystallography. Careful analysis of the crystal data revealed high degree of chain linearity with a potential for 1,n-topochemical polymerization. Next, photophysical properties of 2 were studied in details by experimental and advanced theoretical methods (ab initio HF as well as DFT calculations involving both the ground and excited state geometry optimization). These properties are similar to the properties of the parent polyyne C6H 5(C≡C)4C6H5 previously described in literature (in particular, the lowest electronic excited singlet state (S1) of 2 is a dark state). This was confirmed by the experimental facts, namely, few progressions of the stretching mode (a g) of the polyyne chain, starting from different "false origins" lying below the second excited (bright) state (S2), were observed in the fluorescence excitation spectrum. The red shift of the electronic spectra (155 cm-1 and 300 cm-1 for absorption and fluorescence, respectively) and an increase of an energy gap between S 1 and S2 states by 450 cm-1 are the effects of methylation of C6H5(C≡C)4C 6H5 to 2. Theoretical results showed that in the excited state of 2 a shortening of single bonds and elongation of triple bonds occurred. This is in accordance with an observation of a long progression of the stretching vibration mode in the experimental absorption spectrum of 2. Besides that, stretching vibration of the polyyne chain is also active in the fluorescence spectra. © 2010 Elsevier B.V. All right reserved.

Klocek J.,TU Brandenburg | Henkel K.,TU Brandenburg | Kolanek K.,TU Brandenburg | Broczkowska K.,Wroclaw University of Technology | And 4 more authors.
Thin Solid Films | Year: 2012

Among an extremely large number of possible fullerene applications in the field of electronics, optics and photovoltaics, C 60-cages are also considered as a promising dopant for low dielectric constant (low-k) materials. In this study, we incorporated C 60 species into a 3-aminopropyltrimethoxysilane (APTMS) based material. We prepared thin films by spin coating. Using X-ray photoelectron spectroscopy we analyzed the time-related interactions between the components of the prepared samples and the influence of the C 60 replacement by its better soluble derivative [6,6]-phenyl-C 61-butyric acid methyl ester (PCBM) on the chemical properties of the material. We applied atomic force microscopy to investigate the surface texture and thicknesses of the obtained films. In order to obtain information concerning the electrical properties of the material we performed capacitance-voltage characterization. We have proven that the increase of C 60 species realized by PCBM incorporation within the APTMS-based matrix reduces the dielectric constant of the examined films while preserving its homogeneity. © 2011 Elsevier B.V. All rights reserved.

Smolarek J.,University of Silesia | Marynowski L.,University of Silesia | Spunda K.,Wroclaw Research Center Ltd | Trela W.,Polish Geological Institute National Research Institute
Mineralogia | Year: 2014

A number of independent methods have been used to measure the thermal maturity of Silurian rocks from the Holy Cross Mountains in Poland. Black shales are characterized by diverse TOC values varying from 0.24-7.85%. Having calculated vitrinite equivalent reflectance using three different formulas, we propose that the most applicable values for the Silurian rocks are those based on Schmidt et al. (2015) equation. Based on this formula, the values range from % 0.71 VReqvVLR (the vitrinite equivalent reflectance of the vitrinite-like macerals) to % 1.96 VReqvVLR. Alternative, complementary methods including Rock Eval pyrolysis and parameters based on organic compounds (CPI, Pr/n-C17, Ph/n-C18, MPI1, and MDR) from extracts did not prove adequate as universal thermal maturity indicators. We have confirmed previous suggestions that Llandovery shales are the most likely Silurian source rocks for the generation of hydrocarbons in the HCM. © 2014 Justyna Smolarek et al., published by De Gruyter Open.

Wojcik A.B.,Wroclaw Research Center Ltd | Wojcik A.B.,Hybrid Glass Technologies Inc. | John L.,Wroclaw Research Center Ltd | John L.,Wroclaw University | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

The series of inorganic-organic hybrid materials were prepared from silane precursors by the sol-gel process. The resulted perfluorinated organosilicate liquid oligomers were applied on glass substrates and cured by heat yielding hard, clear and well adhering films. The films porosity, water contact angle, refractive index, and absorption in UV-Vis and IR were measured to characterize optical and physicochemical properties of the prepared films. The perfluorinated organosilicate films exhibited excellent optical transparency, low refractive indices, low porosity as well as non-wetting, hydrophobic behavior. © 2011 SPIE.

Kubik R.,University of Silesia | Kubik R.,Wroclaw Research Center Ltd | Uhl D.,Senckenberg Forschungsinstitut and Naturmuseum Frankfurt | Marynowski L.,University of Silesia
Annales Societatis Geologorum Poloniae | Year: 2015

Charcoals from the Upper Triassic vertebrate-bearing clays of the Zawiercie area (Upper Silesia, S-Poland) were analyzed using petrographic methods, to reconstruct burning temperatures as well as taphonomic processes. SEM and reflected light microscopy show excellent preservation of charcoals most probable connected with early diagenetic permineralization by calcite. The charcoal was assigned to three morphotypes, probably corresponding to three different fossil taxa. Fusinite reflectance data suggest, that the highest temperature reached above 600 °C (fusinite reflectance of 3.59%), what counterparts to the lower limit crown fire temperature. The values for most of the samples are lower (ca. 1% to 2.5%) what is typical for surface fires. In many cases fusinite reflectance values depends on the measured zone within the sample. Such zonation formed due to charring temperature differences. In zones remote from the potential fire source, reflectance values gradually decreases. It implies that calculation of fire temperatures based on average fusinite reflectance values might be too far-reaching simplification. Occurrence of fungal hyphae within the charcoal supports the interpretation of a predomination of surface fire, consuming dead twigs and stems. The low content of micro-charcoals in charcoal-bearing rocks as well as roanded to sub-roanded shapes of large specimens indicates that they were transported after burning, deposited away from the burning area, and finally early diagenetic mineralization. © 2015, Geological Society of Poland. All rights reserved.

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