Filters
total: 1938
filtered: 1724
-
Catalog
Chosen catalog filters
displaying 1000 best results Help
Search results for: DRGANIA SAMOWZBUDNE
-
Base-Catalyzed, Solvent-Free Synthesis of Rigid V-Shaped Epoxydibenzo[b,f][1,5]diazocines
Publication -
In Depth Analysis of Chiroptical Properties of Enones Derived from Abietic Acid
Publication -
Photoinduced Isomerization of 23-Oxosapogenins: Conformational Analysis and Spectroscopic Characterization of 22-Isosapogenins
Publication -
Chromane helicity rule – scope and challenges based on an ECD study of various trolox derivatives
Publication -
Amine-Catalyzed Direct Aldol Reactions of Hydroxy- and Dihydroxyacetone: Biomimetic Synthesis of Carbohydrates
Publication -
Bypassing the stereoselectivity issue: transformations of Kinugasa adducts from chiral alkynes and non-chiral acyclic nitrones
Publication -
A Unique and Stable Polyproline I Helix Sorted out from Conformational Equilibrium by Solvent Polarity
Publication -
Practical Method for the Absolute Configuration Assignment of tert/tert 1,2-Diols Using Their Complexes with Mo2(OAc)4
Publication -
The Oxolane Ring Opening of Some Muramic Acid Derivatives Under Acidic Conditions
Publication -
Chemical Reduction of 2,4,6-Tricyano-1,3,5-triazine and 1,3,5-Tricyanobenzene. Formation of Novel 4,4‘,6,6‘-Tetracyano-2,2‘-bitriazine and Its Radical Anion
Publication -
Toward an Understanding of the Chemiluminescence Accompanying the Reaction of 9-Carboxy-10-methylacridinium Phenyl Ester with Hydrogen Peroxide
Publication -
Enantiomeric Resolution of N,N'-Dimethyldithiodianthranilide through Diastereomeric silver(I) complex. Chiroptical spectra, racemization barrier and molecular self-assembly
PublicationN,N'-dimetyloditiodiantranilid, związek o chiralności płaszczyznowej, rozdzielono na enancjomery. Optycznie czynne molekuły uzyskano w wyniku tworzenia chiralnego kompleksu N,N'-dimetyloditiodiantranilidu z solą srebrową kwasu (1S)-kamforosulfonowego. W oparciu o badania rentgenostrukturalne monokryształu uzyskanego kompleksu określono absolutną konfigurację przykoordynowanego ligandu jako (R). Enancjomery N,N'-dimetyloditiodiantranilid...
-
Conformation Properties, Chiroptical Spectra, and Molecular Self-Assembly of 2,3-Piperazinodiones and Their Dithiono Analogues
PublicationRodzina chiralnych cyklicznych oksamidów została otrzymana przez kondensację optycznie czynnych 1,2-diamin ze szczawianem dietylu. Tionowanie produktów odczynnikiem Lawessona doprowadziło do chiralnych 2,3-dipiperazynodionów. Geometrie cząsteczkowe badano z użyciem obliczeń kwantowo-mechanicznych DFT i porównano z wynikami analizy krystalograficznej. Sześcioczłonowy pierścień heterocykliczny przyjmuje konformację półkrzesłową,...
-
Synthesis and structural investigation of N-acyl selenophosphoramides
PublicationN-acylowane amidy kwasu O,O-neopentylidenomonoselenofosforowego, w zależności od podstawnika na atomie azotu, krystalizują jako konformery zawierające selen w pozycji ekwatorialnej bądź aksjalnej. Wyniki tych eksperymentów wyjaśniono działaniem efektu anomerycznego.
-
Investigation of morphological and electrical properties of the PMMA coating upon exposure to UV irradiation based on AFM studies
PublicationCelem badania było określenie wpływu promieniowania ultrafioletowego na morfologię powierzchni powłoki i na jej właściwości elektryczne. Cienka powłoka z polimetakrylanu metylu została nałożona na podłoże stalowe metodą zanurzeniową. Oceny stanu przed ekspozycją UV i w jej trakcie dokonywano przy użyciu mikroskopu sił atomowych. Na obrazach AFM zaobserwowano pojawienie się mikropęknięć. Celem zweryfikowania czy wykryte nieciągłości...
-
Fate of Ionic Liquids in Soils and Sediments
PublicationZrozumienie losu cieczy jonowych w glebach i osadach dennych jest istotnym elementem ich implementacji z zachowaniem idei zrównoważonego rozwoju. Niniejsza publikacja zawiera analizę i podsumowanie danych dotyczących oddziaływań cieczy jonowych w roztworach wodnych oraz agregacji na powierzchniach stałych. Zaobserwowano, że silnie lipofilowe ciecze jonowe zawierające długi łańcuch węglowodorowy lub duży organiczny anion wykazują...
-
Lower rim substituted p-tert-Butylcalix[4]arenes: Part XI. New ester derivatives of calix[4]arene, their ionophoric properties and x-ray structure studies
PublicationPrzedstawiono syntezę 6-ciu nowych estrowych pochodnych kaliks[4]arenuw konformacji stożkowej. Pierwsze badania kompleksowania jonów metali przeprowadzone w membranach elektrod jonoselektywnych (ISE) potwierdziły kompleksowanie jonów sodu w sposób selektywny. Zaprezentowano strukturę rentgenowską monokryształów związku 6.
-
Solid phase microextraction combined with chromatography - a powerful tool for determination of warfare agents and related compounds
PublicationOpisano zastosowanie mikroekstrakcji do fazy stacjonarnej do izolacji wzbogacania środków bojowych i produktów ich degradacji w powietrzu, wodzie i glebie oraz próbkach bilogicznych. Na etapie oznaczeń końcowych stosuje się najczęściej chromatografię gazową. Anality można pobierać przez bezpośrednie zanurzenie włókna w próbce ciekłej i gazowej oraz w fazie nadpowierzchniowej. Stosując SPME-GC można osiągnąć niskie granice oznaczalności...
-
Application of Monoferrocenylsumanenes Derived from Sonogashira Cross-Coupling or Click Chemistry Reactions in Highly Sensitive and Selective Cesium Cation Electrochemical Sensors
Publication -
Correction to Aromatic Dendrimers Bearing 2,4,6-Triphenyl-1,3,5-triazine Cores and Their Photocatalytic Performance
Publication -
Supramolecular Interactions between β-Cyclodextrin and the Nucleobase Derivatives of Ferrocene
Publication -
Aromatic Dendrimers Bearing 2,4,6-Triphenyl-1,3,5-triazine Cores and Their Photocatalytic Performance
Publication -
Multispectral impedance quality testing of coil-coating system using principal component analysis
PublicationThe task of quality checking of the coil-coated system was undertaken using impedance spectroscopy. In order to properly characterize the system the new impedance spectrum was calculated as an averaged result of 12 experimental spectra obtained from 12 different places of the sample at the same time of immersion in 3% of NaCl. The experimental spectra were recorded for a 24-h period at 1 h intervals between starting points of each...
-
Influence of Carbohydrate Residues on Antibacterial Activity of Vancomycin
Publication -
Botanical and geographical origin characterization of polish honeys by headspace SPME-GCxGC-TOFMS
PublicationVolatile organic compounds (VOCs) composition of Polish honeys obtained from various geographical regions was studied. Headspace solid phase microextraction (HS-SPME) using Divinylbenzene/Carboxen/Polydimethylsiloxane-coated fibers was used in combination with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC× GC-TOFMS) because of the complexity of the samples. Acacia, linden, rapeseed, buckwheat...
-
Benzophosphol-3-yl Triflates as Precursors of 1,3-Diarylbenzophosphole Oxides
PublicationAsimplemethodforthesynthesisof3-arylbenzophospholeoxidesunderSuzuki−Miyauracouplingconditionshasbeenpresented.Itemploysbenzophosphol-3-yltriflatestartingmaterialswhich,priortoourwork,hadnotbeenusedforthesynthesisof3-arylbenzophospholeoxides.Thereactionsproceedover24handprovidealibraryof3-arylbenzophospholeoxides.Thesyntheticaccesstothebenzophosphol-3-yltriflateshasbeenimproved.Thepreliminaryphotophysicalpropertiesofsome3-arylbenzophospholeoxideshavebeeninvestigatedbyabsorptionandemissionmeasurements.Thetheoreticalcalculationswereperformedtoestablishstructure−propertyrelationships.
-
Pincer Complexes Based on Phosphinoaminopyridines: Synthesis, Structural Characterization and Catalytic Applications
Publication -
Thermal decomposition of polyurethane pressure-sensitive adhesives dispersions
Publication -
The thermal degradation of acrylic pressure-sensitive adhesives based on butyl acrylate and acrylic acid
Publication -
Arylation of enelactams using TIPSOTf: reaction scope and mechanistic insight
Publication -
Regioselective synthesis of novel 4,5-diaryl functionalized 3,4-dihydropyrimidine-2(1H)-thiones via a non-Biginelli-type approach and evaluation of their in vitro anticancer activity
Publication -
Anticorrosive and antimicrobial efficiency of photopolymerizable phosphorus (meth)acrylate oligomers-based coating materials
Publication -
Synthesis of Polycyclic δ-Lactams with Bridged Benzomorphan Skeleton: Selectivity and Diversity Driven by Substituents
Publication -
Small isomeric push–pull chromophores based on thienothiophenes with tunable optical (non)linearities
Publication -
Performance of zinc-rich coatings evaluated using AFM-based electrical properties imaging
PublicationThe paper presents the results of investigation of polyvinyl zinc-rich coating exposed to 97% relativehumidity atmosphere for 40 days. Condition of the coating and evolution of its protective properties weredetermined with the novel AFM-based approach capable of providing surface profiles, local dc currentmaps as well as local impedance spectra. The proposed technique allowed insight into the local changesof coating topography...
-
Bio-based semi-aromatic polyesters for coating applications
PublicationLinear and branched bio-based semi-aromatic (co)polyesters were evaluated as resins for solvent-basedand powder coatings. Dimethyl-2,5-furandicarboxylate (DMF), 2,3-butanediol and various multifunc-tional comonomers were used to synthesize amorphous hydroxyl-end-capped (co)polyesters. The resinswere cross-linked using the -caprolactam blocked trimer of isophorone diisocyanate. Both the solvent-based and powder coatings proved to...
-
Multivariate analysis of impedance data obtained for coating systems of varying thickness applied on steel
PublicationElectrochemical impedance spectroscopy (EIS) has proven to be a valuable test method for the electrochemical characterization of protective coatings on metals. The common way of analysis in impedance spectroscopy is to model the impedance spectrum by means of an equivalent circuit and to extract the quantity of interest using optimization techniques. A model, corresponding to the behavior of the sample under testing, is important...
-
Transparent nanocomposite coatings based on epoxy and layered double hydroxide: Nonisothermal cure kinetics and viscoelastic behavior assessments
PublicationLayered double hydroxide (LDH) has a particular place in clay family because of its flame retardant action. The nanoplatelet-like structure of LDH makes possible development of polymer composites with cationic or anionic nature structures in which macromolecules are positioned in between nanoplatelet galleries. In this work, neat epoxy and its transparent nanocomposite coatings with sodium dodecylbenzene sulfonate (SDBS)-modified...
-
The changes of crosslink density of polyurethanes synthesised with using recycled component. Chemical structure and mechanical properties investigations.
PublicationThis paper aims at the utilisation of glycerolysate (Gly) obtained in polyurethane recycling process by means of crude glycerine, which has in its structure hydroxyl end groups that allow for further processing. Polyurethanes (PUs) were synthesised using prepolymer method with the mixture of neat polyol and glycerolysate, in different ratios, with 4,4-diphenylmethane diisocyanate (MDI). The prepolymer was subsequently extended...
-
Degradation of protective coatings in steel chimneys of flue gas desulfurisation system
PublicationThis paper presents problems associated with corrosion of steel stacks and changes in philosophy of corrosion protection when implemented into flue gas desulphurization systems. In-situ tests were taken by means of electrochemical impedance spectroscopy at the stack which discharges flue gas before wet lime/limestone desulphurization. A very quick electrolyte absorption by the spherical infill vinylester coating was found using...
-
Determination of time dependence of coated metal electrical and electrochemical parameters during exposure using principal component analysis
PublicationThe use of the principal component analysis (PCA) permits the complex and quantitative analysis of the time dependence of electrical and electrochemical parameters of coated metal obtained by fitting impedance data. So far, changes in electrical and electrochemical parameters during exposure were analyzed independently. In this way, some of the information contained in the relationship between changes in parameters over time are...
-
Acid-aided epoxy-amine curing reaction as reflected in epoxy/Fe3O4 nanocomposites: Chemistry, mechanism, and fracture behavior
PublicationThis work seeks to answer the question whether or not the presence of acid functional groups accelerate epoxyamine curing reaction. Epoxy/Fe3O4 nanocomposite was considered as a case, where discussions are based on chemistry, mechanism behind curing reactions and fracture behavior influenced by acid assistance to crosslinking. Fe3O4 magnetic nanoparticles (MNPs) with nanosilica decorative layer (B-MNP) were synthesized and subsequently...
-
Stereoselective Alkylation of Indole with 5-Arylidene-Meldrum’s Acids in the Presence of Organocatalysts
PublicationBackground: Indole motif is frequently present in biologically active compounds. Enantiomerically pure or enriched 2,2-dimethyl-5-(aryl(1H-indol-3-yl)methyl)-1,3-dioxane-4,6-diones can be considered as a convenient starting point for the synthesis of a indole ring fused with cyclic ketones with biological activity. Preparation of chiral 2,2-dimethyl-5-(aryl(1H-indol-3-yl)methyl)-1,3-dioxane- 4,6-diones requires the reaction of...
-
Curing epoxy resin with anhydride in the presence of halloysite nanotubes: the contradictory effects of filler concentration
PublicationEpoxy resins can be cured with a wide variety of curing agents such as amines and anhydrides, but anhydride curing would be more favorable for research purpose because of epoxy-anhydride curing taking place slowly at room temperature. Incorporation of natural nanosized minerals into epoxy is of environmental importance. Halloysite nanotubes (HNTs) display chemical properties similar to those of silica and alumina, and hydroxyl...
-
5-Bromo-2′-deoxycytidine—a potential DNA photosensitizer
PublicationA double-stranded oligonucleotide, 80 base pairs in length, was multiply labeled with 5-bromo-2′-deoxycytidine (BrdC) using polymerase chain reaction (PCR). The modified oligonucleotide was irradiated with 300 nm photons and its damage was assayed by employing DHPLC, LC-MS and denaturing polyacrylamide gel electrophoresis (PAGE). Two types of damage were demonstrated, namely, single strand breaks (SSBs) and intrastrand cross-links...
-
Unconditionally blue: Curing epoxy with polyethylene glycol (PEG) surface-functionalized Zn Fe3-O4 magnetic nanoparticles
PublicationNanoparticles govern early (chemical-controlled) and late (diffusion-controlled) stages of epoxy crosslinking, respectively. Surface functionalization of nanoparticles with macromolecules was recognized as an effective route to compensate for inadequate diffusion-controlled crosslinking. However, the effect of bulk composition amended with cations having catalytic effect towards epoxy ring opening has remained hitherto undescribed....
-
Towards β-selectivity in functional estrogen receptor antagonists
PublicationBased on the benzo[b]naphtho[1,2-d]furan and benzo[b]naphtho[1,2-d]thiophene frameworks, a series of ligands with different basic side chains (BSCs) has been synthesized and pharmacologically evaluated. Also, their binding modes have been modelled using docking techniques. It was found that the introduction of a BSC in these systems brings about a decrease of affinity for both estrogen receptors α and β in an in vitro competitive...
-
Helicity discrimination in N,N'-dibenzoyl-1,2,3,4,7,8,9,10-octahydro-1,10-phenanthrolines and their thiono- and selenocarbonyl analogues by inclusion complexation with chiral diols
PublicationX-ray crystallographic analysis of the title compounds revealed that they assume a folded helical con- formation of an approximate C2 symmetry in the solid state. Dithioamide, diselenoamide and monoselenoamide were resolved to enantiomers by inclusion crystallization with optically active diols (TADDOLs). The absolute configuration of the guest molecules in the complexes was assigned as P. The optical activity of the resolved compounds...
-
Developing electrochemical measurements in order to assess anti-corrosive coatings more effectively
PublicationCelem pracy było sprawdzenie powtarzalności wyników uzyskanych metodą pomiaru szumu (Electrochemical Noise method - ENM) elektrochemicznego wykonanych na powłokach organicznych w konfiguracji bez połączenia z podłożem metalowym (NOCS - No Connection to the Substrate). NOCS polega na wykonaniu pomiarów na trzech teoretycznie takich samych obszarach badanego układu. W takim układzie nie jest wymagane połączenie elektryczne z metalowym...
-
Properties of nano-Fe3O4 incorporated epoxy coatings from Cure Index perspective
PublicationThe mission of an advanced epoxy-based nanocomposite coating is to provide a given substrate with protection against an unwelcome guest; e.g. corrosive molecules/media, environmental stress, flame, thermal degradation or microorganisms. In such systems, the degree to which superior properties can be guaranteed depends on the state of network formation in the epoxy in the presence of nanoparticles. For low-filled epoxy nanocomposite coatings,...