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- Author:
- Wang, Chengpeng; Naren, Nevin A.; Zheng, Pengfei; Dong, Guangbin
- Source:
- Journal of the American Chemical Society 2020 v.142 no.19 pp. 8962-8971
- ISSN:
- 1520-5126
- Subject:
- chemical bases, etc ; acids; alkynes; catalytic activity; chemical bonding; cyclohexanones; hydrides; moieties; palladium; protonation; Show all 10 Subjects
- Abstract:
- ... Site-selective C–C bond formation through the direct coupling of C(sp³)–H bonds with unsaturated hydrocarbons represents an atom-economical and redox-neutral way to functionalize chemically inert positions, such as those β to a carbonyl group. While most existing β-functionalization methods utilize a directing group (DG) strategy, here we report a Pd-catalyzed intramolecular β-alkenylation of keto ...
- DOI:
- 10.1021/jacs.0c02654
-
http://dx.doi.org/10.1021/jacs.0c02654
- Author:
- Veigure, Ruta; Lossmann, Krit; Hecht, Max; Parman, Elisabeth; Born, Rasmus; Leito, Ivo; Herodes, Koit; Kipper, Karin
- Source:
- Journal of chromatography 2020 v.1613 pp. 460667
- ISSN:
- 0021-9673
- Subject:
- chemical bases, etc ; acids; additives; ammonium acetate; ammonium bicarbonate; chemical species; liquid chromatography; pH; tandem mass spectrometry; Show all 9 Subjects
- Abstract:
- ... This research focuses on retention mechanisms in a LC column with C18 stationary phase when novel eluent additives (HFIP, HFTB and TFE as well as NFTB and perfluoropinacol) are used. The retention factors between novel eluent additives and conventional ones like ammonium acetate and ammonium bicarbonate at different eluent pH values were compared. A simple set of drug-like molecules, widely spread ...
- DOI:
- 10.1016/j.chroma.2019.460667
-
https://dx.doi.org/10.1016/j.chroma.2019.460667
- Author:
- Xiong, Xue; Qi, Meiling
- Source:
- Journal of chromatography 2020 v.1612 pp. 460627
- ISSN:
- 0021-9673
- Subject:
- chemical bases, etc ; acids; additives; adsorption; chemical species; gas chromatography; isomers; naphthalene; phenols; polyethylene glycol; polypropylenes; Show all 11 Subjects
- Abstract:
- ... This work presents the investigation of utilizing adenine-functionalized polypropylene glycol (APPG) for capillary gas chromatographic separations. The statically coated APPG column (0.25 mm i.d.) showed moderate polarity and high column efficiencies of 4660 plates/m and 4376 plates/m determined by n-octanol and naphthalene, respectively. Remarkably, the APPG column baseline resolved all the compo ...
- DOI:
- 10.1016/j.chroma.2019.460627
-
https://dx.doi.org/10.1016/j.chroma.2019.460627
- Author:
- Oh, Jongwon; Jeon, Inkyu; Kim, Dowon; You, Younghoon; Baek, Dahye; Kang, Seok Ju; Lee, Jiseok
- Source:
- ACS applied materials & interfaces 2020 v.12 no.4 pp. 4934-4943
- ISSN:
- 1944-8252
- Subject:
- chemical bases, etc ; acids; anions; chemical interactions; color; cyanides; drinking water; fluorescence; hydrophobicity; mechanical stress; nanocrystals; solvents; Show all 12 Subjects
- Abstract:
- ... Although the unique optical signaling properties of polydiacetylene (PDA) have been exploited in diverse bio-chemosensors, the practical application of most PDA sensor systems is limited by their instability in harsh environments and fluorescence signal weakness. Herein, a universal design principle for a highly stable PDA sensor system with a practical dual signaling capability is developed to de ...
- DOI:
- 10.1021/acsami.9b20438
-
http://dx.doi.org/10.1021/acsami.9b20438
- Author:
- Liu, Liu Leo; Stephan, Douglas W.
- Source:
- Chemical Society reviews 2019 v.48 no.13 pp. 3454-3463
- ISSN:
- 1460-4744
- Subject:
- chemical bases, etc ; Lewis acids; free radicals; Show all 3 Subjects
- Abstract:
- ... While conventional approaches to stabilizing main group radicals have involved the use of Lewis acids or bases, this tutorial review focuses on new avenues to main group radicals derived from combinations of donor and acceptor molecules. Reactions involving the use of both classical Lewis acid–base adducts and frustrated Lewis pair systems are discussed and the subsequent reactivity is considered. ...
- DOI:
- 10.1039/c8cs00940f
-
http://dx.doi.org/10.1039/c8cs00940f
- Author:
- Borůvka, Luboš; Vašát, Radim; Němeček, Karel; Novotný, Radek; Šrámek, Vít; Vacek, Oldřich; Pavlů, Lenka; Fadrhonsová, Věra; Drábek, Ondřej
- Source:
- Geoderma regional 2020 v.21 pp. e00286
- ISSN:
- 2352-0094
- Subject:
- chemical bases, etc ; acidification; atmospheric deposition; base saturation; cations; conservation areas; decision making; forests; liming; models; mountains; organic horizons; peat; probability; Czech Republic; Show all 15 Subjects
- Abstract:
- ... Acidification due to acid atmospheric deposition affected strongly soils of many forested areas with long-term consequences. Liming is often used for amelioration, however, detailed assessment of soil and stand conditions is necessary to avoid possible undesirable effects. The aim of this paper is to apply and compare two spatial modelling methods to delineate probability that the criteria for pot ...
- DOI:
- 10.1016/j.geodrs.2020.e00286
-
https://dx.doi.org/10.1016/j.geodrs.2020.e00286
- Author:
- Xu, Donghao; Carswell, Alison; Zhu, Qichao; Zhang, Fusuo; de Vries, Wim
- Source:
- The Science of the total environment 2020 v.713 pp. 136249
- ISSN:
- 0048-9697
- Subject:
- chemical bases, etc ; acidity; aluminum; arable soils; base saturation; cations; fertilizers; grasses; grasslands; liming; neutralization; nitrogen; simulation models; soil acidification; soil pH; sulfur; topsoil; United Kingdom; Show all 18 Subjects
- Abstract:
- ... Liming is widely used to reduce the impacts of soil acidification and optimize soil pH for agricultural production. Whether models can simulate the effect of liming on soil pH, and base saturation (BS), and thereby guide lime application, is still largely unknown. Long-term experimental data from a grassland (Park Grass, 1965–2012) and arable land (Sawyers Field, 1962–1972) at Rothamsted Research, ...
- DOI:
- 10.1016/j.scitotenv.2019.136249
-
https://dx.doi.org/10.1016/j.scitotenv.2019.136249
- Author:
- Cheng, Feng; Tompsett, Geoffrey A.; Murphy, Caroline M.; Maag, Alex R.; Carabillo, Nicholas; Bailey, Marianna; Hemingway, Jeremy J.; Romo, Carla I.; Paulsen, Alex D.; Yelvington, Paul E.; Timko, Michael T.
- Source:
- ACS sustainable chemistry & engineering 2020 v.8 no.17 pp. 6877-6886
- ISSN:
- 2168-0485
- Subject:
- chemical bases, etc ; acids; biofuels; calcium; carbon; catalysts; catalytic activity; clay; crystal structure; energy; food waste; heat; hydrothermal liquefaction; industrial wastes; leaching; oxides; synergism; Show all 17 Subjects
- Abstract:
- ... Industrial wastes and natural mixed oxide materials were evaluated as inexpensive heterogeneous catalysts for catalytic hydrothermal liquefaction (CHTL) of food wastes. Red mud and red clay achieved biocrude carbon yields of 47.0 and 39.5% with higher heating values (HHVs) of 40.2 and 37.7 MJ kg–¹, respectively, which were much greater than those without the catalyst (biocrude carbon yield of 19.7 ...
- DOI:
- 10.1021/acssuschemeng.0c02059
-
http://dx.doi.org/10.1021/acssuschemeng.0c02059
- Author:
- Gao, Wei-Ting; Chen, Qing; Du, Ming-Gu; Zhang, Wei-Ming; Cao, Chang-Yan; Song, Wei-Guo
- Source:
- Green chemistry 2020 v.22 no.7 pp. 2213-2224
- ISSN:
- 1463-9270
- Subject:
- chemical bases, etc ; alanine; amino alcohols; byproducts; catalysts; catalytic activity; cost analysis; drugs; electrodialysis; feedstocks; green chemistry; hydrochloric acid; hydrogen; hydrogenation; phosphoric acid; stereoselective synthesis; sulfuric acid; Show all 17 Subjects
- Abstract:
- ... Optically pure amino alcohols are widely used as essential building blocks of catalysts and auxiliaries in asymmetric synthesis, especially in pharmaceuticals. Catalytic hydrogenation has been regarded as the most effective route to produce chiral amino alcohols, but it is still unsatisfactory, which mainly manifests in the involvement of extra acids and bases, thus generating a large amount of in ...
- DOI:
- 10.1039/c9gc02460c
-
http://dx.doi.org/10.1039/c9gc02460c
- Author:
- Kučera, Aleš; Holik, Ladislav; Cerro, Elena Muñoz; Petříček, Jan
- Source:
- Journal of forestry research 2020 v.31 no.2 pp. 375-386
- ISSN:
- 1007-662X
- Subject:
- chemical bases, etc ; Fagus sylvatica subsp. sylvatica; Picea abies; ammonium; ammonium nitrogen; cation exchange capacity; forest ecosystems; forest management; forest types; mixed forests; nitrate nitrogen; nitrates; nitrogen; soil minerals; Show all 14 Subjects
- Abstract:
- ... Gaps play a key role in forest ecosystem development and result from either natural processes or targeted forest management activities. The aim of this study was to investigate the interrelationships of soil properties in each of three forest types and two treatments, and to identify factors that influence levels of soil mineral nitrogen forms. The relation between mineral nitrogen and factors of ...
- DOI:
- 10.1007/s11676-018-0822-3
-
http://dx.doi.org/10.1007/s11676-018-0822-3
- Author:
- Forino, Martino; Picariello, Luigi; Lopatriello, Annalisa; Moio, Luigi; Gambuti, Angelita
- Source:
- European food research & technology 2020 v.246 no.4 pp. 733-743
- ISSN:
- 1438-2377
- Subject:
- chemical bases, etc ; acetaldehyde; catechin; color; mass spectrometry; metabolites; model food systems; nuclear magnetic resonance spectroscopy; p-coumaric acid; polymers; pyruvic acid; red wines; ultraviolet-visible spectroscopy; Show all 13 Subjects
- Abstract:
- ... The reactivity of malvidin-3-O-glucoside with acetaldehyde, pyruvic and p-coumaric acids, was separately studied in wine model solution in the presence and absence of catechin, by UV–Visible spectrophotometry, NMR and Mass spectrometry. These naturally occurring metabolites were selected on account of their role in determining the red wine color. The scientific bases underlying the wine color are ...
- DOI:
- 10.1007/s00217-020-03442-x
-
http://dx.doi.org/10.1007/s00217-020-03442-x
- Author:
- Burns, Douglas A.; McDonnell, Todd C.; Rice, Karen C.; Lawrence, Gregory B.; Sullivan, Timothy J.
- Source:
- Hydrological processes 2020 v.34 no.7 pp. 1498-1513
- ISSN:
- 0885-6087
- Subject:
- chemical bases, etc ; acidification; aquatic ecosystems; atmospheric deposition; cations; ecoregions; emissions; nitrogen; sediments; soil; streams; sulfates; sulfur; surface water; Eastern United States; Europe; Show all 16 Subjects
- Abstract:
- ... Acidic atmospheric deposition has adversely affected aquatic ecosystems globally. As emissions and deposition of sulfur (S) and nitrogen (N) have declined in recent decades across North America and Europe, ecosystem recovery is evident in many surface waters. However, persistent chronic and episodic acidification remain important concerns in vulnerable regions. We evaluated acidification in 269 he ...
- DOI:
- 10.1002/hyp.13668
-
http://dx.doi.org/10.1002/hyp.13668
- Author:
- Wang, Hui; Dong, Ying; Tong, Xuejiao; Liu, Xinghai; Shao, Jie; Shi, Renyong; Hong, Zhineng; Xu, Renkou; Jiang, Jun
- Source:
- Journal of soils and sediments 2020 v.20 no.3 pp. 1424-1434
- ISSN:
- 1439-0108
- Subject:
- chemical bases, etc ; Ultisols; acid soils; acidity; alkalinity; application rate; biochar; canola; carbonates; cations; crops; feedstocks; pyrolysis; soil pH; straw; temperature; China; Show all 17 Subjects
- Abstract:
- ... PURPOSE: Regional differences in the alkaline properties and base cation richness of canola straw biochars, and their amelioration effects on an acidic Ultisol, were studied in the present investigation. MATERIALS AND METHODS: The biochars were produced using straw from canola crops grown in four different regions and soils from south to north of China as feedstock, namely Yingtan biochar (YTBC), ...
- DOI:
- 10.1007/s11368-019-02504-2
-
https://dx.doi.org/10.1007/s11368-019-02504-2
- Author:
- Escher, Beate I.; Abagyan, Ruben; Embry, Michelle; Klüver, Nils; Redman, Aaron D.; Zarfl, Christiane; Parkerton, Thomas F.
- Source:
- Environmental toxicology and chemistry 2020 v.39 no.2 pp. 269-286
- ISSN:
- 0730-7268
- Subject:
- chemical bases, etc ; bioaccumulation; ecotoxicology; guidelines; hazard characterization; hydrophobicity; lipids; mitochondria; models; organic acids and salts; pH; quantitative structure-activity relationships; screening; toxicity; toxicity testing; zwitterions; Show all 16 Subjects
- Abstract:
- ... Ionizable organic chemicals (IOCs) such as organic acids and bases are an important substance class requiring aquatic hazard evaluation. Although the aquatic toxicity of IOCs is highly dependent on the water pH, many toxicity studies in the literature cannot be interpreted because pH was not reported or not kept constant during the experiment, calling for an adaptation and improvement of testing g ...
- DOI:
- 10.1002/etc.4602
-
http://dx.doi.org/10.1002/etc.4602
- Author:
- Culman, Steve W.; Mann, Meredith; Sharma, Stuti; Saeed, Muhammad Tariq; Fulford, Anthony M.; Lindsey, Laura E.; Brooker, Aaron; Dayton, Elizabeth; Warden, Randall; Joern, Brad
- Source:
- Communications in soil science and plant analysis 2020 v.51 no.1 pp. 86-97
- ISSN:
- 1532-2416
- Subject:
- chemical bases, etc ; Mehlich-3 phosphorus; ammonium acetate; calcium; cations; field crops; magnesium; nutrient content; nutrients; phosphorus; potassium; potassium fertilizers; soil; Indiana; Michigan; Ohio; Show all 16 Subjects
- Abstract:
- ... Field crop fertilizer recommendations for Ohio, Indiana and Michigan are currently based on the Bray P1 extractant for phosphorus (P) and the ammonium acetate extractant (AA) for base cations. The fertilizer recommendations in this Tri-State region are currently being revised and will use the Mehlich-3 soil test extractant as the new basis for P and potassium (K) fertilizer recommendations. The go ...
- DOI:
- 10.1080/00103624.2019.1695825
-
http://dx.doi.org/10.1080/00103624.2019.1695825
- Author:
- Bader, Taysir K.; Xu, Feng; Hodny, Michael H.; Blank, David A.; Distefano, Mark D.
- Source:
- Journal of organic chemistry 2019 v.85 no.3 pp. 1614-1625
- ISSN:
- 1520-6904
- Subject:
- chemical bases, etc ; acids; bioactive properties; cysteine; geranylgeranyl diphosphate synthase; lighting; moieties; organic chemistry; peptides; photolysis; thiols; Show all 11 Subjects
- Abstract:
- ... Photoremovable caging groups are useful for biological applications because the deprotection process can be initiated by illumination with light without the necessity of adding additional reagents such as acids or bases that can perturb biological activity. In solid phase peptide synthesis (SPPS), the most common photoremovable group used for thiol protection is the o-nitrobenzyl group and related ...
- DOI:
- 10.1021/acs.joc.9b02751
-
http://dx.doi.org/10.1021/acs.joc.9b02751
- Author:
- Chan, Michael Ho-Yeung; Leung, Sammual Yu-Lut; Yam, Vivian Wing-Wah
- Source:
- Journal of the American Chemical Society 2019 v.141 no.31 pp. 12312-12321
- ISSN:
- 1520-5126
- Subject:
- chemical bases, etc ; acids; luminescence; nuclear magnetic resonance spectroscopy; pyridines; solvents; temperature; Show all 7 Subjects
- Abstract:
- ... A series of oligo(ethynylpyridine)-containing alkynylplatinum(II) terpyridine/bzimpy (bzimpy = 2,6-bis(N-alkylbenzimidazol-2′-yl)pyridine) metallofoldamers has been designed and synthesized to investigate the potential applications of metallofoldamers imparted by the rich spectroscopic responses of Pt···Pt interactions. Apart from the control of the folding/unfolding processes by solvent compositi ...
- DOI:
- 10.1021/jacs.9b04447
-
http://dx.doi.org/10.1021/jacs.9b04447
- Author:
- Oukacine, Farid; Choisnard, Luc; Gèze, Annabelle; Peyrin, Eric
- Source:
- Journal of chromatography 2019 v.1597 pp. 220-224
- ISSN:
- 0021-9673
- Subject:
- chemical bases, etc ; acids; capillary electrophoresis; chromatography; drugs; electric current; metal ions; titration; Show all 8 Subjects
- Abstract:
- ... Titration methods are routinely used in the laboratories for the quantification of acids and bases, for the complexometric determination of metal ions and for the ion-pair titrations of drugs in pharmaceutical control. They also find application in a wide variety of chemical and biochemical studies. However, conventional titration methods (CTM) require large amounts of samples that are not always ...
- DOI:
- 10.1016/j.chroma.2019.03.014
-
https://dx.doi.org/10.1016/j.chroma.2019.03.014
- Author:
- Atmaca, Ufuk
- Source:
- Tetrahedron 2019 pp. 130467
- ISSN:
- 0040-4020
- Subject:
- chemical bases, etc ; acetonitrile; carboxylic acids; catalysts; chemical reactions; chemical structure; prices; solvents; sulfamates; synthesis; Show all 10 Subjects
- Abstract:
- ... Effective synthesis of novel sulfamates from various carboxylic acids has been developed in the presence of chlorosulfonyl isocyanate (CSI) in mild conditions. Several acids, bases and solvents effects were investigated for one-pot synthesis sulfamates as a catalyst. Finally, triflic acid was found to possess efficiently under optimized conditions in acetonitrile. This method is easy, fair price a ...
- DOI:
- 10.1016/j.tet.2019.130467
-
https://dx.doi.org/10.1016/j.tet.2019.130467
- Author:
- Yang, SeungCheol; Choi, Young-Woo; Choi, Jiyeon; Jeong, Namjo; Kim, Hanki; Nam, Joo-Youn; Jeong, Haejun
- Source:
- ACS sustainable chemistry & engineering 2019 v.7 no.14 pp. 12200-12213
- ISSN:
- 2168-0485
- Subject:
- chemical bases, etc ; acids; cation-exchange membranes; electrodialysis; electrolytes; energy efficiency; polymers; solvents; toxicity; Show all 9 Subjects
- Abstract:
- ... Pore-filling ion-exchange membranes have been produced via complex, low energy efficient, and toxic processes, including repetitive impregnation to fully fill the porous substrates with polymer electrolytes, and using polar organic solvents and acids/bases for optional postmodifications. In the present work, we analyzed the characteristics of a pore-filling cation-exchange membrane (PCEM) fully fi ...
- DOI:
- 10.1021/acssuschemeng.9b01450
-
http://dx.doi.org/10.1021/acssuschemeng.9b01450