345 research outputs found
Photophysical and Electrical Properties of Highly Luminescent 2/6-Triazolyl-Substituted Push-Pull Purines
This work is supported by the ERDF 1.1.1.1. activity project No. 1.1.1.1/16/A/131. The authors thank Dr. sc. ing. Jānis Zicāns and Dr. sc. ing. Remo Merijs Meri for DSC analyses.New push-pull N(9)-alkylated 6-piperidino-2-triazolylpurine and 2-piperidino-6-triazolylpurine derivatives are synthesized, and their optical and optoelectronic properties are comprehensively characterized with experimental and computational methods. The compounds possess intense violet or blue fluorescence with fluorescence quantum yields of up to 91% in solution and 40% in host-free films. Depending on their structural composition, the compounds have ionization energy in the range of 5.25-6.04 eV, electron affinity of 2.18-3.15 eV, and triplet energy of 2.52-2.95 eV. Due to the presence of hole-transporting purine and electron-transporting triazole fragments, compounds exhibit bipolar charge-transportation ability. Despite the favorable emissive properties of the studied push-pull purines, their electroluminescence in thin films is quenched owing to large current densities that are present even at a moderate driving voltage. This marks application directions related to a predominantly charge-transportation functionality as the most suitable for this compound class. © Article published under the CC BY licence.European Regional Development Fund 1.1.1.1, 1.1.1.1/16/A/131; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2
Ogļhidrāti, heterocikli un sēra dioksīds
Scientific research within the fields of carbohydrate and heterocyclic chemistry and application of liquid sulfur dioxide in organic chemistry is discussed. The review covers the scientific achievements of the research group lead by prof. M. Turks in the period 2008-2013
Library of New Dimeric 1,2,3-Triazolyl Glycohybrids
Synthesis of novel triazolyl disaccharide
Nucleophilic Ring Opening of N-Protected Leakadine in Liquid Sulfur Dioxide
Here we present a new synthetic process of Leakadine 1 opening with metal
halides and other nucleophiles in liquid sulfur dioxide as a solvent
Copper and Ruthenium Catalyzed "Clicking" of Carbohydrate Derivatives
Šajās tēzēs apskatīta vara un rutēnija katalizēta oligosaharīda-triazolu konjugātu sintēz
Monosaharīdu un mazgaistošu spirtu sililatvasinājumu iegūšana un GH-MS analīze
Ieteikts jauns reaģents GH-derivatizācijā
Synthesis and Applications of (-)-(S)-3-Aminoquinuclidine- Derived Thiourea
A synthesis of enantiopure thiourea organocatalyst based on (-)-(S)-3-aminoquinuclidine dihydrochloride was developed with quantitative product yield. The catalyst was tested in different reactions: asymmetric Michael addition of ketones and malonates to nitroalkenes, nitromethane 1,4-addition to trans-chalcone, and Friedel-Crafts alkylation of indoles with trans-β-nitrostyrene. The novel thiourea proved to catalyze the aforementioned reactions and expected products were obtained in mediocre yields and low enantioselectivities
Synthesis of Optically Active 5-Alkoxy-6-methylcyclohex-2-en-1-ones and 4-Alkoxy-5-methylcyclopent-1-enyl Benzoate
Hetero-Dīlsa-Aldera rekcijās starp diēniem un sēra dioksīdu alilsilānu klātienē rodas vērtīgi produkti, kurus ar metatēzes reakcijas palīdzību var pārvērst attiecīgos hirālos cikloheksēnona vai ciklopentanona atvasinājumos. Šīs grupas savienojumi ir nozīmīgi parfimērijas industrijā
Synthesis of Triazole-Linked Oligosaccharides
Apskatīta ar triazola starpcukura saiti saistītu oligosaharīdu sintēze. Darbā izmantota 1,3-dipolārā ciklopievienošanās reakcij
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