نتایج جستجو برای: fluoro β diketones
تعداد نتایج: 185255 فیلتر نتایج به سال:
The reaction of formaldehyde with β-diketones (Hantzsch reaction) has been often employed for derivatizing formaldehyde to the fluorescent compounds.1,2 Among βdiketones, 5,5-dimethyl-1,3-cyclohexanedione (dimedone, Fig. 1) seems to be the most promising because of the strong fluorescence intensity and stability of the formed compound. Recently, we developed a method for concentrating trace hyd...
Seawater reverse osmosis (SWRO) desalination plants generate high volumes of concentrates, which contain, in addition to major salts, some elements growing interest minor concentrations. This is the case lithium, highly demanded battery industry. In this work, separation Li+ from model SWRO brines has been evaluated by obtaining extraction curves with combination extractants DBM•TOPO and FDOD•T...
A series of tetrasubstituted fluoroalkene derivatives were synthesized by the reaction of α-fluoro-β-carbonyl benzothiazol-2-yl sulfones with various nucleophiles in good yields with high stereoselectivities. The predominant cis configuration of fluorine and alkynyl groups was observed. A single isomer was obtained when a ketone, acetate or amide was used as the substrate in the presence of a b...
A series of unsymmetrical 1,3-diaryl-β-diketones 1-6 displaying molecular conformation-dependent fluorescence quantum yields have been synthesized. Crystals with planar molecular conformation such as 1, 2, 3 and 4 are highly fluorescent (φf: 39-53%), and the one holding slightly twisted conformation (5) is moderately luminescent (φf = 17%), while crystal 6 possessing heavily bent structure is c...
Reactions of the ligands, 2,6-diacetylpyridine bis(Smethylisothiosemicarbazone) and 2,6-diacetylpyridine bis(Sbutylisothiosemicarbazone) with ruthenium(III), rhodium(III) and iridium(III) have been studied and their structures have been proposed based on elemental analyses, molar conductance, magnetic moment, spectral data (IR, H NMR, FAB mass) and thermal investigations. The ligands behave as ...
Some functionalized 1,2,4,5-tetrasubstituted imidazole derivatives were synthesized using a one-pot, four component reaction involving 1,2-diketones, aryl aldehydes, ammonium acetate and substituted aromatic amines. The synthesis has been efficiently carried out in a solvent free medium using β-cyclodextrin-propyl sulfonic acid as a catalyst to afford the target compounds in excellent yields. T...
INTRODUCTION Detection of (subclinical) synovitis is relevant for both early diagnosis and monitoring of therapy of rheumatoid arthritis (RA). Previously, the potential of imaging (sub)clinical arthritis was demonstrated by targeting the translocator protein in activated macrophages using (R)-[11C]PK11195 and positron emission tomography (PET). Images, however, also showed significant peri-arti...
In recent years, there has been a significant interest in beverages with increased biological value, such as beer blueberries. this study, blueberries were added at the beginning of maturation lager an initial extract 12, 14 and 16ºP. The effect addition on yeast metabolism was investigated concentration ethanol, higher alcohols, esters, aldehydes, vicinal diketones final measured compared to c...
Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (...
The unique properties of fluorine atom on nucleic acid backbone can offer stricking functional and structural features. In order to extend the biological applications L-type acid, we chemically incorporate fluoro-modification into 2′-position L-cytidine, obtain a series fluoro-modified L-DNAs/ L-RNAs. Our melting study indicates that 2′-fluoro-modification does not disrupt thermostabilities wil...
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