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Wyniki wyszukiwania dla: physical organic chemistry
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Stereoselective Alkylation of Indole with 5-Arylidene-Meldrum’s Acids in the Presence of Organocatalysts
PublikacjaBackground: 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...
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5-Bromo-2′-deoxycytidine—a potential DNA photosensitizer
PublikacjaA 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...
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Methylene bridged glycoluril dimers: synthetic methods
PublikacjaZaprezentowano syntezę pochodnych glikolurylu tworzących ściśle sprecyzowane dimeryczne struktury w roztworze wodnym. Opisano diastereoselektywną syntezę pochodnych o strukturze amfifilowej.
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Benzophosphol-3-yl Triflates as Precursors of 1,3-Diarylbenzophosphole Oxides
PublikacjaAsimplemethodforthesynthesisof3-arylbenzophospholeoxidesunderSuzuki−Miyauracouplingconditionshasbeenpresented.Itemploysbenzophosphol-3-yltriflatestartingmaterialswhich,priortoourwork,hadnotbeenusedforthesynthesisof3-arylbenzophospholeoxides.Thereactionsproceedover24handprovidealibraryof3-arylbenzophospholeoxides.Thesyntheticaccesstothebenzophosphol-3-yltriflateshasbeenimproved.Thepreliminaryphotophysicalpropertiesofsome3-arylbenzophospholeoxideshavebeeninvestigatedbyabsorptionandemissionmeasurements.Thetheoreticalcalculationswereperformedtoestablishstructure−propertyrelationships.
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Creation of Hydrogen Bonded 1D Networks by Cocrystallization of N,N`-bis(2-pyridyl) aryldiamines with Dicarboxylic Acids.Tworzenie 1D sieci krystalicznych poprzez kokrystalizację N,N` -bis(2-piry- dylo) arylodiamin z kwasami dikarboksylowymi.
PublikacjaZsyntetyzowano szereg N,N`-bis(2-pirydylo) arylodiamin, a następnie otrzymano serię kompleksów w/w amin z kwasami dikarboksylowymi oraz kwasem kwadratowym w postaci monokryształów. Jednostki N,N`-bis(2-pirydylo) arylodiamin i kwasy dikarboksylowe oddziaływują ze sobą poprzez wiązania wodorowe tworząc ośmioczłonowy cykliczny układ. W kompleksach 1:1 cząsteczki układają się w jedno-wymiarową sieć krystaliczną tworzoną przy udziale...
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Selected Methods for the Chemical Phosphorylation and Thiophosphorylation of Phenols
PublikacjaThis Focus Review gathers together a selection of methods for the chemical phosphorylation of phenols that employ three‐ and four‐coordinate phosphorus compounds. Phosphorylated scaffolds can exhibit enhanced properties compared to their non‐phosphorylated analogues, such as increased biological activity and increased/decreased solubility; as such, phosphorus compounds have gained more and more interest in organic and medicinal...
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Atropoisomerism in Mono- and Diaryl-Substituted 4-Amino-2,6-lutidines
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Front Cover: Chiral Molecular Cages Based on Cyclotriveratrylene and Sucrose Units Connected with p ‐Phenylene Linkers (Eur. J. Org. Chem. 6/2021)
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Chiral Molecular Cages Based on Cyclotriveratrylene and Sucrose Units Connected with p ‐Phenylene Linkers
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Determination of the Stereostructure of Pyrimidine Nucleoside Derivatives with a Combination of Various Chiroptical Methods
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Dimolybdenum Tetraacetate as an Auxiliary Chromophore in Absolute Configuration Determination of Amino Acids from their Circular Dichroism Spectra - Foundations and Developments
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Diosgenyl 2-amino-2-deoxy-β-D-galactopyranoside: synthesis, derivatives and antimicrobial activity
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Regioselective Synthesis of 6‐Vinyl‐3,6‐dihydropyridine‐2(1H)‐ones through Simple Addition of a Vinylmagnesium “Ate” Complex to 2‐Pyridones
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Sequential Synthesis of Organosilicon‐Linked 2‐Methoxypyridines by Non‐Cryogenic ortho‐Metallation Using the nBu2TMPMg·Li Reagent and Hydrosilylation
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Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules
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General, Mild, and Metal-Free Functionalization of Indole and Its Derivatives Through Direct C3-Selenylation
PublikacjaA very mild method for the introduction of functionalized alkylselenyl group at C-3 position of the indole ring was developed. The proposed procedure consists of an electrophilic substitution of indole and its derivatives with bis(O,O-diisopropoxyphosphorothioyl) diselenide and subsequent cleavage of the P–Se bond with tetrabutylammonium fluoride in the presence of various electrophilic reagents. This method can be successfully...
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Convenient and Efficient Diastereoselective Preparation of Functionalized Z -Alkenyl Sulfides
PublikacjaWe have developed an efficient and convenient regio‐ and stereoselective reduction of the alkynyl sulfides with pinacolborane in the presence of copper(I) chloride to produce (Z)‐alkenyl sulfides in good and very good yields. The functionalized alkynyl sulfides are readily available based on the reaction of lithium acetylides with thiotosylates under mild conditions.
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Acylic congener of cucurbituril: synthesis and recognition properties.
PublikacjaZaprezentowano syntezę analogów acyklicznych cucurbiturilu oraz ich zdolności do kompleksowania wybranych 16 amin, dioli, kwasów dikarboksylowych, pochodnych guanidyny oraz pirydyny. Obserwowane tworzenie kompleksów przebiegało około 180 razy słabiej niż dla cucurbiturilu. Wyniki te świadczą o potencjalnych możliwościach zbliżonych do analogów cyklicznych pod względem tworzenia kompleksów i rozpoznawania wyżej wymienionych...
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Hydration of aprotic donor solvents studied by means of FTIR spectroscopy
PublikacjaThe paper attempts to explain the mutual influence of nonpolar and electron-donor groups on solute hydration,the problem of big importance for biological aqueous systems. Aprotic organic solvents have been used asmodel solutes, differing in electron-donating power. Hydration of acetonitrile, acetone, 2-butanone, andtriethylamine has been studied by HDO and (partially) H2O spectra. The quantitative version of...
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Deep Eutectic Solvents or Eutectic Mixtures? Characterization of Tetrabutylammonium Bromide and Nonanoic Acid Mixtures
PublikacjaDeep eutectic solvents have quickly attracted the attention of researchers because they better meet the requirements of green chemistry and thus have the potential to replace conventional hazardous organic solvents in some areas. To better understand the nature of these mixtures, as well as expand the possibilities of their use in different industries, a detailed examination of their physical properties, such as density, viscosity,...
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Fragmentation of Tetrahydrofuran Molecules by H+, C+, and O+ Collisions at the Incident Energy Range of 25–1000 eV
PublikacjaWe have studied fragmentation processes of the gas-phase tetrahydrofuran (THF) molecules in collisions with the H+, C+, and O+ cations. The collision energies have been varied between 25 and 1000 eV and thus covered a velocity range from 10 to 440 km/s. The following excited neutral fragments of THF have been observed: the atomic hydrogen H(n), n = 4–9, carbon atoms in the 2p3s 1P1, 2p4p 1D2, and 2p4p 3P states and vibrationally...
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Photophysics of Ru(II) Dyads Derived from Pyrenyl-Substitued Imidazo[4,5-f][1,10]phenanthroline Ligands.
PublikacjaThe photophysics of a series of Ru(II) dyads based on the 2-(1-pyrenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline ligand was investigated. The ability of these metal complexes to intercalate DNA and induce cell death upon photoactivation makes them attractive photosensitizers for a range of photobiological applications, including photodynamic therapy. In the present study, time-resolved transient absorption and emission spectroscopy...
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Valence and Ionic Lowest-Lying Electronic States of Isobutyl Formate Studied by High-Resolution Vacuum Ultraviolet Photoabsorption, Photoelectron Spectroscopy, and Ab Initio Calculations
PublikacjaThe highest resolution vacuum ultraviolet photoabsorption spectrum of isobutyl formate, C5H10O2, yet reported is presented over the energy range 4.5−10.7 eV (275.5−118.0 nm) revealing several new spectral features. Valence and Rydberg transitions and their associated vibronic series observed in the photoabsorption spectrum have been assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator...
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Photophysics of Soret-Excited Tin(IV) Porphyrins in Solution
PublikacjaThe photophysics of low-chlorin tin(IV) tetraphenylporphyrin dihydroxide, a core building block for axially substituted supramolecular tin porphyrin constructs, has been studied in a variety of hydrogen-bonding, nonpolar, and aprotic polar solvents using steady-state, nanosecond, and femtosecond time-resolved emission, and femtosecond time-resolved absorption methods. In hydrogen-bonding solvents the metalloporphyrin exists as...
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Influence of Protonation State on the Excited State Dynamics of a Photobiologically Active Ru(II) Dyad
PublikacjaThe influence of ligand protonation on the photophysics of a ruthenium (Ru) dyad bearing the 2-(1-pyrenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline (ippy) ligand was investigated by time-resolved transient absorption spectroscopy. It was found that changes in the protonation state of the imidazole group led to changes in the electronic configuration of the lowest lying excited state. Formation of the fully deprotonated imidazole...
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Yields and Time-of-Flight Spectra of Neutral High-Rydberg Fragments at the K Edges of the CO2 Molecule
PublikacjaWe have studied the production of neutral fragments in high-Rydberg (HR) states at the C 1s and O 1s edges of the CO2 molecule by performing two kinds of experiments. First, the yields of neutral HR fragments were measured indirectly by ionizing such fragments in a static electric field and by collecting resulting singly charged positive ions as a function of the photon energy. Such measurements reveal not only excitations below...
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Investigation of Protein Folding by Coarse-Grained Molecular Dynamics with the UNRES Force Field
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Charge Loss in Gas-Phase Multiply Negatively Charged Oligonucleotides
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Theoretical Study of Polymerization Mechanism of p-Xylylene Based Polymers
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Ligand Design by Ionomers. ESR of MoV in Perfluorinated Ionomer Supports
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Catalysis on polymer supports: ESR of molybdenum (V) dispersed in poly(acrylic acid) matrices
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Two-Dimensional Spatial−Spectral ESR Imaging of Diffusion Based on Molybdenum(V)
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Excess Electron Attachment to Disulfide-Bridged l,l-Cystine. An ab Initio Study
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Negatively Charged Xanthine. I. Anions Formed by Canonical Isomers
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Temperature Dependence of the Dissociative Electron Attachment to 2-Thiothymine
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First Evidence of Rhombic (NaCl)2-. Ab Initio Reexamination of the Sodium Chloride Dimer Anion
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Coulomb-Assisted Dissociative Electron Attachment: Application to a Model Peptide
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Why Are SiX5– and GeX5– (X = F, Cl) Stable but Not CF5– and CCl5–?
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Inverse Potassium Hydride: A Theoretical Study
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Unusual and Conventional Dative Bond Formation by s2 Lone Pair Donation from Alkaline Earth Metal Atoms to BH3, AlH3, and GaH3
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Possible Formation of H3O+ Cations Due to Aluminum Fluoride Interactions with Water
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The Only Stable State of O2- Is the X 2Πg Ground State and It (Still!) Has an Adiabatic Electron Detachment Energy of 0.45 eV
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Negative Ion Formation in Sodium Chloride TrimerAn ab Initio Study
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Bound-Excited Electronic States of the Anion of 2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane
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Simulating Electron Transfer Attachment to a Positively Charged Model Peptide
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Caralumane Superacids of Lewis and Brønsted Character
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Formation of Enormously Strongly Bound Anionic Clusters Predicted in Binary Superacids
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Theoretical Study of Damage to DNA by 0.2−1.5 eV Electrons Attached to Cytosine
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Prediction of Thymine Dimer Repair by Electron Transfer from Photoexcited 8-Aminoguanine or Its Deprotonated Anion
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Mechanism for Repair of Thymine Dimers by Photoexcitation of Proximal 8-Oxo-7,8-dihydroguanine
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