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101.
Grala A Ejfler J Jerzykiewicz LB Sobota P 《Dalton transactions (Cambridge, England : 2003)》2011,40(16):4042-4044
Alkyl-(S,S)-O-lactyllactate was prepared by chemoselective alcoholysis of lactide LA mediated by a magnesium catalyst. When ROH reacted with LA it yielded the ring-opened product R-(S,S)-O-lactyllactate exclusively, which remained intact as long as LA was present in the reaction mixture. Consumption of LA caused the reaction to proceed further giving R-(S)-lactate. 相似文献
102.
Han T Utko J Jerzykiewicz LB Sobota P 《Dalton transactions (Cambridge, England : 2003)》2011,40(47):12660-12662
Polylactide conjugates of the muscle contraction agent Pridinolum (PriOH = 1,1-diphenyl-3-(1-piperidinyl)-1-propanol) were prepared directly by ring-opening polymerization of L-lactide (L-LA) mediated by the pridinolum magnesium complex [Mg(μ,η(2)-OPri)(η(1)-OPri)](2). The ancillary O,N - bifunctional drug as a ligand stabilizes the magnesium species and initiates L-LA polymerization affording a polymer chain terminated by covalently attached drug molecules to the PLLA through ester linkers to form PriO-PLLA conjugate. Up to 80% of the pridinolum can be released from the conjugate by treatment with deuterated hydrochloric acid DCl at pH = 1.5 for 10 h at 37 °C. 相似文献
103.
Magdalena Jabłońska Lucjan Chmielarz Agnieszka Węgrzyn Katarzyna Guzik Zofia Piwowarska Stefan Witkowski Richard I. Walton Peter W. Dunne František Kovanda 《Journal of Thermal Analysis and Calorimetry》2013,114(2):731-747
Layered double hydroxides (LDHs) containing Mg2+, Cu2+ or Zn2+ cations in the MeII positions and Al3+ and Fe3+ in the MeIII positions were synthesized by co-precipitation method. Detailed studies of thermal transformation of obtained LDHs into metal oxide systems were performed using high temperature X-ray diffraction in oxidising and reducing atmosphere, thermogravimetry coupled with mass spectrometry and temperature-programmed reduction. The LDH samples calcined at 600 and 900 °C were tested in the role of catalysts for selective oxidation of ammonia into nitrogen and water vapour. It was shown that all copper congaing samples presented high catalytic activity and additionally, for the Cu–Mg–Al and Cu–Mg–Fe hydrotalcite samples calcined at 600 °C relatively high stability and selectivity to dinitrogen was obtained. An increase in calcination temperature to 900 °C resulted in a decrease of their catalytic activity, possibly due to formation of well-crystallised metal oxide phases which are less catalytically active in the process of selective oxidation of ammonia. 相似文献
104.
EPR in the environmental control: Copper complexes and free radicals in soil and municipal solid waste compost 总被引:1,自引:0,他引:1
A. Jezierski J. Drozd M. Jerzykiewicz Y. Chen K. J. Kaye 《Applied magnetic resonance》1998,14(2-3):275-282
Quantitative EPR technique was applied to examine Cu(II) complexes and free radicals in soil and municipal solid waste composts. Production and stabilization of free radicals in humic and humic-like substances depend on transition metal containing red-ox systems in soil. Termination of the reaction pathways yields relatively stable semiquinone free radicals in the polyphenol and melanoidin matrices. EPR investigations of municipal solid waste composts in different stages of their maturity show distinct correlation between free radical concentration and microbiological activity. Copper(II) sorption by living microorganisms and formation of the copper(II) complexes by humic substances in soils (Cambisols and Luvisols) result in decrease of the concentration of the semiquinone radicals. The Cu(II) complexes formed by various natural humic and humic-like substances produced in the composts were characterized on the basis of EPR measurements. The process of solubilization of inorganic copper compounds in soil and composts, and free radical activity in soil and composts can be characterized using EPR technique as the monitoring method. 相似文献
105.
5-(2-Aminophenyl)isoxazoles are obtained in good yields by the reaction of 2-(trifluoromethyl)aniline with dilithio derivatives of oximes of acetone, 3-pentanone, propiophenone, and cyclohexanone. An analogous synthesis of a substituted isoxazole from 4-(trifluoromethyl)aniline and 3-pentanone oxime and the synthesis of a substituted pyrazole from 2-(trifluoromethyl)aniline and 3-pentanone hydrazone are less efficient. 相似文献
106.
107.
Piotr Chmielewski Valery A. Ozeryanskii Lucjan Sobczyk Alexander F. Pozharskii 《Journal of Physical Organic Chemistry》2007,20(9):643-648
The primary 1H/2H isotope effect for a number of protonated naphthalene proton sponges (DMAN‐s) was measured and correlated with the δ(1H) value and IR spectroscopic characteristics of the [NHN]+ hydrogen bonds. A particular role of the unusual anharmonicity expressed in the isotopic ratio ISR ? is discussed when the fundamental vibrational levels are close to the barrier top for proton/deuteron motion. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
108.
Janas Z Wiśniewska D Jerzykiewicz LB Sobota P Drabent K Szczegot K 《Dalton transactions (Cambridge, England : 2003)》2007,(20):2065-2069
The direct reaction between [VCl(3)(thf)3] or [VO(OEt)3] and 2,2'-thiobis{4-(1,1,3,3-tetramethyl-butyl)phenol (tbopH(2)) leads to the formation of [V(2)(micro-tbop-kappa(3)O,S,O)2Cl(2)(CH(3)CN)(2)] (1).4CH(3)CN or [V(2)(micro-OEt)2(O)2(tbop-kappa(3)O,S,O)2] (2), respectively, in high yield. Compounds 1 and 2 were characterized by chemical and physical techniques including X-ray crystallography and variable temperature magnetic susceptibility studies (J = -29.1 cm(-1)) for 1. Complexes 1 and 2 were supported on MgCl2 and when activated with aluminium alkyls, were found to effectively polymerize ethene to produce polyethylene with a narrow molecular weight distribution M(w)/M(n) approximately 3. 相似文献
109.
110.
Lucjan Chmielarz Andrzej Kowalczyk Magdalena Wojciechowska Paweł Boroń Barbara Dudek Marek Michalik 《Chemical Papers》2014,68(9):1219-1227
The intercalation of natural montmorillonite with SiO2, SiO2-Al2O3 or SiO2-TiO2 pillars by the surfactant-directed method resulted in the formation of high surface area porous materials; these were tested as catalytic supports for the process of selective catalytic reduction of NO (DeNOx). The incorporation of titanium or aluminium into the structure of the silica pillars significantly increased the surface acidity of the clay samples. Iron and copper were deposited onto the surface of the pillared clays mainly in the form of monomeric isolated cations and oligomeric metal oxide species. The contribution of the latter species was higher in the clay intercalated with SiO2-TiO2 pillars than in the samples modified with SiO2 and SiO2-Al2O3 pillars. The pillared clay-based catalysts were active in the DeNOx process but, in this group, the best results were obtained for the clay intercalated with SiO2-TiO2 pillars and doped with iron and copper. The catalytic performance of the samples is discussed in respect of their surface acidity and active forms of transition metal species deposited. 相似文献