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161.
Urszula Śliwińska Florian P. Pruchnik Stanisław Ułaszewski Małgorzata Latocha Dominika Nawrocka-Musiał 《Polyhedron》2010
Reaction of dimers [M(η5-C5Me5)Cl2]2 (M-Rh, Ir) with quinolin-8-ol in molar ratio 1:2 leads to formation of monomer complexes [Rh(η5-C5Me5)Cl(qol)] (1) and [Ir(η5-C5Me5)Cl(qol)] (2) (qol = quinolin-8-olate). Compounds 1 and 2 have been characterized with elemental analysis and spectroscopic methods. 1H NMR spectra revealed that quinolin-8-olate is coordinated via oxygen and nitrogen atoms. The 1H NMR and 13C NMR spectra showed that carbon and hydrogen atoms of pentamethylcyclopentadienyl ligand are equivalent. The structure of rhodium complex has been calculated using DFT B3LYP method. The calculated geometry of complex 1 agrees very well with data found for rhodium complexes containing Cl, C5Me5 and qol ligands. Both complexes are active antitumor and antibacterial agents. 相似文献
162.
Urszula Domańska Zuzanna Żołek-Tryznowska 《The Journal of chemical thermodynamics》2010,42(3):363-370
163.
Urszula Domańska Maciej Zawadzki M. Marc Tshibangu Deresh Ramjugernath Trevor M. Letcher 《The Journal of chemical thermodynamics》2010,42(9):1180-1186
Quinolinium ionic liquid has been prepared from 1-butylquinolinium bromide as a substrate. The work includes specific basic characterization of synthesized compound by NMR spectra, elementary analysis and water content. The basic thermal properties of the pure IL, i.e. melting and glass-transition temperatures, as well as the enthalpy of fusion have been measured using a differential scanning microcalorimetry technique (DSC). (Solid + liquid) phase equilibria (SLE) and (liquid + liquid) phase equilibria (LLE) for the binary systems: ionic liquid (IL) N-butylquinolinium bis{(trifluoromethyl)sulfonyl}imide, {([BQuin][NTf2]) + aromatic hydrocarbon (benzene, or toluene, or methylbenzene, or propylbenzene, or thiophene), or an alcohol (ethanol, or 1-butanol, or 1-hexanol, or 1-octanol, or 1-dodecanol)} have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from (260 to 330) K. For the binary systems, the simple eutectic diagrams were observed with immiscibility in the liquid phase with an upper critical solution temperature (UCST). For mixtures with alcohols, it was observed that with increasing chain length of an alcohol the solubility decreases and the UCST increases. In the case of mixture (IL + benzene, or alkylbenzene, or thiophene) the eutectic systems with mutual immiscibility in the liquid phase with very high UCSTs were observed. These points were not detectable with our method and they were observed at low ionic liquid mole fraction. Densities at high temperatures were determined and extrapolated to T = 298.15 K. Well-known UNIQUAC, and NRTL equations have been used to correlate experimental SLE data sets. For the systems containing immiscibility gaps {IL + an alcohol} parameters of the LLE correlation equation have been derived using only the NRTL equation. 相似文献
164.
This paper studies the group theoretical protocol of Diffie?CHellman key exchange in the case of symmetrical group ${S_{p^n}}$ and more general Cremona group ${C(\mathbb K^n)}$ of polynomial automorphisms of free module ${\mathbb K^n}$ over arbitrary commutative ring ${\mathbb K}$ . This algorithm depends very much on the choice of the base ${g_n \in C( \mathbb K^n)}$ . It is important to work with the base ${g_n \in C( \mathbb K^n)}$ , which is a polynomial map of a small degree and a large order such that the degrees of all powers ${g_n^k}$ are also bounded by a small constant. We suggest fast algorithms for generation of a map ${g_n={f_n} \xi_nf_n^{-1}}$ , where ?? n is an affine transformation (degree is 1) of a large order and f n is a fixed nonlinear polynomial map in n variables such that ${f_n^{-1}}$ is also a polynomial map and both maps f n and ${f_n^{-1}}$ are of small degrees. The method is based on properties of infinite families of graphs with a large cycle indicator and families of graphs of a large girth in particular. It guaranties that the order of g n is tending to infinity as the dimension n tends to infinity. We propose methods of fast generation of special families of cubical maps f n such that ${f_n^{-1}}$ is also of degree 3 based on properties of families of graphs of a large girth and graphs with a large cycle indicator. At the end we discuss cryptographical applications of maps of the kind ?? f n ???1 and some graph theoretical problems motivated by such applications. 相似文献
165.
Monika Pitucha Liliana Mazur Urszula Kosikowska Anna Pachuta‐Stec Anna Malm ukasz Popioek Zofia Rzaczyska 《Heteroatom Chemistry》2010,21(4):215-221
Novel N‐substituted‐3‐amino‐5‐oxo‐4‐phenyl‐2,5‐dihydro‐1H‐pyrazole‐1‐carbothioamide derivatives were synthesized by means of two methods. First is the cyclization reaction of 1‐(cyanophenyl)acetyl‐4‐substituted thiosemicarbazide, and the second one is reaction of cyanophenyl acetic acid hydrazide with isothiocyanate. Structures of new compounds were confirmed by elemental analysis, 1H NMR, and X‐ray diffraction analysis. Biological evaluation showed that some of them possess promising antibacterial activities. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:215–221, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20598 相似文献
166.
167.
Mariusz Mital Nina E. Wezynfeld Tomasz Frczyk Magdalena Z. Wiloch Urszula E. Wawrzyniak Arkadiusz Bonna Carolin Tumpach Kevin J. Barnham Cathryn L. Haigh Wojciech Bal Simon C. Drew 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(36):10606-10610
Accumulation of the β‐amyloid (Aβ) peptide in extracellular senile plaques rich in copper and zinc is a defining pathological feature of Alzheimer′s disease (AD). The Aβ1–x (x=16/28/40/42) peptides have been the primary focus of CuII binding studies for more than 15 years; however, the N‐truncated Aβ4–42 peptide is a major Aβ isoform detected in both healthy and diseased brains, and it contains a novel N‐terminal FRH sequence. Proteins with His at the third position are known to bind CuII avidly, with conditional log K values at pH 7.4 in the range of 11.0–14.6, which is much higher than that determined for Aβ1–x peptides. By using Aβ4–16 as a model, it was demonstrated that its FRH sequence stoichiometrically binds CuII with a conditional Kd value of 3×10−14 M at pH 7.4, and that both Aβ4–16 and Aβ4–42 possess negligible redox activity. Combined with the predominance of Aβ4–42 in the brain, our results suggest a physiological role for this isoform in metal homeostasis within the central nervous system. 相似文献
168.
Aroop K. Roy Urszula G. Wettermark Gary M. Scheide Patty Wisian-neilson Robert H. Neilson 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):147-153
Abstract The reactions of a variety of electrophiles with the N-silyl-P-trifluoroethoxyphosphoranimine anion Me3Sin°P(Me)(OCH2CF3)CH? 2 (1a), prepared by the deprotonation of the dimethyl precursor Me3SiN[dbnd]P(OCH2CF3)Me2 (1) with n-BuLi in Et2O at-78°C, were studied. Thus, treatment of 1a with alkyl halides, ethyl chloroformate, or bromine afforded the new N-silylphosphoranimine derivatives Me3SiN[dbnd]P(Me)(OCH2CF3)CH2R [2: R = Me, 3: R = CH2Ph, 4: R = CH[sbnd]CH2, 5: R = C(O)OEt, and 6: R = Br]. In another series, when 1a was allowed to react with various carbonyl compounds, 1,2-addition of the anion to the carbonyl group was observed. Quenching with Me3SiCl gave the O-silylated products Me3SiN[dbnd]P(Me)(OCH2CF3)CH2°C(OSiMe3)R1R2 [7: R 1 = R 2 = Me; 8: R 1 = Me, R 2 = Ph; 9: R1 = Me, R 2 = CH[sbnd]CH2; and 10: R 1 = H, R 2 = Ph]. Compounds 2–10 were obtained as distillable, thermally stable liquids and were characterized by NMR spectroscopy (1H, 13C, and 31P) and elemental analysis. 相似文献
169.
Łukasz Popiołek Urszula Kosikowska Maria Dobosz Anna Malm 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):468-481
Abstract 1,2,4-triazole and 1,3,4-thiadiazole derivatives are still considered a viable lead structure for the synthesis of more efficient antimicrobial agents having a broad spectrum of activity. This study presents the synthesis and antimicrobial evaluation of a new series of substituted 1,2,4-triazole and 1,3,4-thiadiazole derivatives. Reaction of 4-phenyl-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-thione with ethyl bromoacetate yields the corresponding ethyl acetate (1). In the subsequent reaction with 100% hydrazine hydrate, the hydrazide (2) was obtained, which was converted with isothiocyanates to new acyl derivatives of thiosemicarbazide (3a–l). The cyclization of these compounds in alkaline media resulted in the formation of new derivatives of 1,2,4-triazole (4a–i), whereas in acidic media new derivatives of 1,3,4-thiadiazole (5a,b,g) were obtained. All synthesized compounds were screened for their in vitro antimicrobial activities. 相似文献
170.
Urszula Chodorow Janusz Parka Przemyslaw Kula Jakub Herman Olga Chojnowska Roman Dabrowski 《Liquid crystals》2013,40(11):1586-1590
In this article, optical properties of four fluoro-substituted 4-propyl-4′-[(4-ethylphenyl)ethynyl] biphenyls and liquid crystal mixture A are presented in the terahertz (THz) range. Birefringence, refractive indices and absorption coefficients for ordinary and extraordinary ray of liquid crystals are described in the range of 0.3 to 3.0 THz. It shows that the measured parameters are dependent on the number and placement of fluorine atoms in the molecules. Measurements have been performed using time-pulsed spectroscopy. 相似文献