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1. Radicals derived from Lewis acid/base pairs

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

2. Rational Design of Multi-Stimuli-Responsive Scaffolds: Synthesis of Luminescent Oligo(ethynylpyridine)-Containing Alkynylplatinum(II) Polypyridine Foldamers Stabilized by Pt···Pt Interactions

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

3. Capillary electrophoretic apparatus for the endpoint detection in microtitration methods

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

4. Efficient and one-pot synthesis of novel sulfamates from carboxylic acids

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

5. R2R Fabrication of Pore-Filling Cation-Exchange Membranes via One-Time Impregnation and Their Application in Reverse Electrodialysis

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

6. Direct β-Alkenylation of Ketones via Pd-Catalyzed Redox Cascade

Author:
Wang, Chengpeng; Rago, Alexander J.; Dong, Guangbin
Source:
Organic letters 2019 v.21 no.9 pp. 3377-3381
ISSN:
1523-7052
Subject:
chemical bases,   etc   ; acids; catalytic activity; chemical reactions; chemical structure; ketones; organobromine compounds; palladium;     Show all 8 Subjects
Abstract:
... A direct β-alkenylation of simple ketones with alkenyl bromides is reported via a Pd-catalyzed redox cascade strategy. The reaction is redox neutral and directing-group-free, in the absence of strong acids or bases. Both cyclic and linear ketones are suitable substrates, and various alkenyl bromides can be coupled. The resulting β-alkenyl ketones are readily derivatized through diverse alkene func ...
DOI:
10.1021/acs.orglett.9b01116

7. Puzzling Aqueous Solubility of Guanine Obscured by the Formation of Nanoparticles B

Author:
Darvishzad, Termeh; Lubera, Tomasz; Kurek, Stefan S.
Source:
The Journal of physical chemistry 2018 v.122 no.30 pp. 7497-7502
ISSN:
1520-5207
Subject:
chemical bases,   etc   ; acids; dissociation; guanine; nanoparticles; pH; physical chemistry; solubility;     Show all 8 Subjects
Abstract:
... Dissolution of guanine in neutral solutions was obscured by peculiar behavior of guanine, indicating an apparent dependence of solubility on the amount of solid guanine used. Here, we demonstrate that the problem is caused by the formation of tiny guanine nanoparticles that tend to grow forming stable particles of ca. 800 nm size. This effect can be minimalized by using small quantities of guanine ...
DOI:
10.1021/acs.jpcb.8b04327

8. Miniaturization and Combinatorial Approach in Organic Electrochemistry

Author:
Mitsudo, Koichi; Kurimoto, Yuji; Yoshioka, Kazuki; Suga, Seiji
Source:
Chemical reviews 2018 v.118 no.12 pp. 5985-5999
ISSN:
1520-6890
Subject:
chemical bases,   etc   ; acids; electrochemistry; electrolysis; electrolytes; polymers; screening;     Show all 7 Subjects
Abstract:
... Recent advances in electro-organic chemistry involving miniaturization, integration, and combinatorial chemistry were reviewed. Microelectrode array technology for site-selective electro-organic reactions and addressable libraries provides a direct and unlabeled method for measuring small-molecule–protein interactions. Electrochemical systems using solid-supported bases and acids (“site separation ...
DOI:
10.1021/acs.chemrev.7b00532

9. Protection of COOH and OH groups in acid, base and salt free reactions

Author:
Zhu, Xiaotao; Qian, Bo; Wei, Rongbiao; Huang, Jian-Dong; Bao, Hongli
Source:
Green chemistry 2018 v.20 no.7 pp. 1444-1447
ISSN:
1463-9270
Subject:
chemical bases,   etc   ; acids; evaporation; filtration; green chemistry; moieties; wastes;     Show all 7 Subjects
Abstract:
... We report an iron-catalyzed general functional group protection method with inexpensive reagents. This environmentally benign process does not use acids or bases, and does not produce waste products. Further purification beyond filtration and evaporation is, in most cases, unnecessary. Free COOH and OH groups can be protected in a one-pot reaction. ...
DOI:
10.1039/c8gc00037a

10. Benzo[ghi]perylene and coronene as ratiometric fluorescence probes for the selective sensing of nitroaromatic explosives

Author:
Hussain, Ejaz; Li, Yongxin; Cheng, Cheng; Zhuo, Huipeng; Shahzad, Sohail Anjum; Ali, Sajjad; Ismail, Mohammad; Qi, Hong; Yu, Cong
Source:
Talanta 2019
ISSN:
0039-9140
Subject:
chemical bases,   etc   ; acids; explosives; fluorescence; fluorescent dyes; fluorometry; models; nitroaromatic compounds; nitrophenols; oxygen; paper; rapid methods; volatile organic compounds;     Show all 13 Subjects
Abstract:
... A simple and efficient fluorometric sensing method is developed for the rapid detection of nitroaromatic explosives, based on the quenching of monomer and excimer emission of benzo[ghi]perylene and coronene. The ratiometric method (IE/IM) offers a linear response as a function of the concentration of picric acid (PA, i.e. 2,4,6-trinitrophenol), which is used as a model example of the nitroaromatic ...
DOI:
10.1016/j.talanta.2019.120316

11. Soil heterogeneity in tree mixtures depends on spatial clustering of tree species

Author:
Sercu, Bram K.; Hertzog, Lionel R.; De Groote, Stefanie R.E.; Baeten, Lander; Lens, Luc; Martel, An; Bonte, Dries; Verheyen, Kris
Source:
Basic and applied ecology 2019 v.39 pp. 38-47
ISSN:
1439-1791
Subject:
chemical bases,   etc   ; carbon nitrogen ratio; cations; forest litter; forests; leaves; mixed stands; mixing; soil heterogeneity; species diversity; topsoil; trees;     Show all 12 Subjects
Abstract:
... Heterogeneity in soil characteristics promotes and maintains coexistence between a diverse set of species. In forests, trees have species-specific impacts on soil abiotic characteristics and mixing of tree species is being promoted as a tool to ensure high levels of diversity and functioning. Yet, limited knowledge is available on the effect of tree species composition and spatial clustering on he ...
DOI:
10.1016/j.baae.2019.06.007

12. Self-Healable Superomniphobic Surfaces for Corrosion Protection

Author:
Ezazi, Mohammadamin; Shrestha, Bishwash; Klein, Nathan; Lee, Duck Hyun; Seo, Sungbaek; Kwon, Gibum
Source:
ACS applied materials & interfaces 2019 v.11 no.33 pp. 30240-30246
ISSN:
1944-8252
Subject:
chemical bases,   etc   ; acids; alcohols; concrete; contact angle; corrosion; durability; finishes; hydrophobicity; ions; mechanical damage; oils; pipelines; steel; surface tension; temperature;     Show all 16 Subjects
Abstract:
... Corrosion-protective surfaces are of the utmost relevance to ensure long-term stability and reliability of metals and alloys by limiting their interactions with corrosive species, such as water and ions. However, their practical applications are often limited either by the inability to repel low surface tension liquids such as oils and alcohols or by poor mechanical durability. Here, a superomniph ...
DOI:
10.1021/acsami.9b08855

13. Context-Dependency of Agricultural Legacies in Temperate Forest Soils

Author:
Blondeel, Haben; Perring, Michael P.; Bergès, Laurent; Brunet, Jörg; Decocq, Guillaume; Depauw, Leen; Diekmann, Martin; Landuyt, Dries; Liira, Jaan; Maes, Sybryn L.; Vanhellemont, Margot; Wulf, Monika; Verheyen, Kris
Source:
Ecosystems 2019 v.22 no.4 pp. 781-795
ISSN:
1432-9840
Subject:
chemical bases,   etc   ; anthropogenic activities; carbon; cations; forest ecosystems; forest soils; nitrogen; pH; phosphorus; soil fertility; soil properties; temperate forests; Europe;     Show all 13 Subjects
Abstract:
... Anthropogenic activities have affected forests for centuries, leading to persistent legacies. Observations of agricultural legacies on forest soil properties have been site specific and contrasting. Sites and regions vary along gradients in intrinsic soil characteristics, phosphorus (P) management and nitrogen (N) deposition which could affect the magnitude of soil property responses to past culti ...
DOI:
10.1007/s10021-018-0302-9

14. Speciation of structural fragments in crude oil by means of isotope exchange in near-critical water and Fourier transform mass spectrometry

Author:
Kostyukevich, Yury; Zherebker, Alexander; Vlaskin, Mikhail S.; Roznyatovsky, Vitaliy A.; Grishin, Yuri K.; Nikolaev, Eugene
Source:
Analytical and bioanalytical chemistry 2019 v.411 no.15 pp. 3331-3339
ISSN:
1618-2642
Subject:
chemical bases,   etc   ; X-radiation; acids; furans; gases; humic substances; isotopes; mass spectrometry; nuclear magnetic resonance spectroscopy; petroleum; spectrometers;     Show all 11 Subjects
Abstract:
... The structures of individual molecules in crude oil remain largely unknown despite the considerable amount of research dedicated to this topic. The extreme complexity of crude oil (recently Marshall reported the observation of more than 400,000 unique compounds in one sample) makes it impossible to separate crude oil into individual compounds and determine their structure by NMR or X-ray spectrosc ...
DOI:
10.1007/s00216-019-01802-5

15. Surface design of durable and recyclable superhydrophobic materials for oil/water separation

Author:
Liu, Yujing; Liu, Ning; Jing, Yannan; Jiang, Xiaohui; Yu, Liangmin; Yan, Xuefeng
Source:
Colloids and surfaces 2019 v.567 pp. 128-138
ISSN:
0927-7757
Subject:
chemical bases,   etc   ; acids; adsorption; colloids; contact angle; durability; hydrophobicity; ice; manufacturing; melamine; oils; paper; recycling; silica; solvents; steel;     Show all 16 Subjects
Abstract:
... Superhydrophobic sponges are very efficient oil-absorbing materials, but their poor durability and recyclability are critical shortcomings in practical applications. To address this issue, we prepared a silica-dodecyltrimethoxysilane (SiO2-DTMS)-modified melamine sponge through an entrapment method. The modified sponge (M-sponge) showed a large water contact angle (172°) and high continuous adsorp ...
DOI:
10.1016/j.colsurfa.2019.01.047

16. Understanding the Diverse Coordination Modes of Thiocyanate Anion on Solid Surfaces

Author:
Wang, Zheng; Liu, Tongfa; Long, Xia; Li, Yuan; Bai, Fuquan; Yang, Shihe
Source:
Journal of physical chemistry 2019 v.123 no.14 pp. 9282-9291
ISSN:
1932-7455
Subject:
chemical bases,   etc   ; Lewis acids; catalysts; cations; coordination compounds; density functional theory; geometry; nitrogen; physical chemistry; solvents; sulfur; thiocyanates;     Show all 12 Subjects
Abstract:
... Thiocyanate anion (SCN–) can coordinate to solid surfaces in various coordination modes, endowing the solid surfaces with different structures and electronic and catalytic properties, but the rules that dictate the coordination preference are poorly understood due to the multiple coordination sites of both SCN– and the solid surfaces as well as the SCN–-lattice mismatch. In this article, extensive ...
DOI:
10.1021/acs.jpcc.9b01457

17. Highly Efficient Supported Palladium–Gold Alloy Catalysts for Hydrogen Storage Based on Ammonium Bicarbonate/Formate Redox Cycle

Author:
Nakajima, Kengo; Tominaga, Mitsuhiro; Waseda, Moe; Miura, Hiroki; Shishido, Tetsuya
Source:
ACS sustainable chemistry & engineering 2019 v.7 no.7 pp. 6522-6530
ISSN:
2168-0485
Subject:
chemical bases,   etc   ; additives; alloy nanoparticles; alloys; ammonium; ammonium bicarbonate; carbon; catalysts; dehydrogenation; formates; gold; hydrogen; hydrogenation; kinetics; palladium;     Show all 15 Subjects
Abstract:
... We have developed supported Pd–Au alloy catalysts for reversible hydrogen storage–release process with high efficiency based on the reversible reactions involving ammonium formate and bicarbonate. Supported Pd–Au random alloy catalysts exhibited a superior activity than supported monometallic Pd and Au catalysts in both bicarbonate hydrogenation and formate dehydrogenation under ambient conditions ...
DOI:
10.1021/acssuschemeng.8b04698

18. Atmospheric deposition control of soil acidification in central Italy

Author:
Cecchini, G.; Andreetta, A.; Marchetto, A.; Carnicelli, S.
Source:
Catena 2019 v.182 pp. 104102
ISSN:
0341-8162
Subject:
chemical bases,   etc   ; acid soils; acidification; atmospheric deposition; calcium; cations; chlorides; evapotranspiration; forest soils; magnesium; monitoring; potassium; rain; sodium; soil acidification; soil water; weathering; Italy;     Show all 18 Subjects
Abstract:
... Acidification is a major soil-forming process, and concerns about acidifying anthropogenic atmospheric deposition make it a significant environmental issue. In the long term, the depletion of exchangeable base cations (BCEs) is the main process underpinning soil acidification. In south-central Italy, acidic soils are not rare and are often located in areas with no excess rainfall over potential ev ...
DOI:
10.1016/j.catena.2019.104102

19. A first record of bulk atmospheric deposition patterns of major ions in southern South America

Author:
Carnelos, D. A.; Portela, S. I.; Jobbágy, E. G.; Jackson, R. B.; Di Bella, C. M.; Panario, D.; Fagúndez, C.; Piñeiro-Guerra, J. M.; Grion, L.; Piñeiro, G.
Source:
Biogeochemistry 2019 v.144 no.3 pp. 261-271
ISSN:
0168-2563
Subject:
chemical bases,   etc   ; air pollution; ammonium; atmospheric deposition; basins; biogeochemical cycles; calcium; chlorides; human population; magnesium; nitrates; potassium; sodium; sulfates; vegetation; Argentina; Uruguay;     Show all 17 Subjects
Abstract:
... Despite the importance of long-term atmospheric deposition of ions for vegetation productivity and biogeochemistry, southern South America lacks long-term deposition records. We report a 6-year-long record of atmospheric deposition measurements of Mg²⁺, Ca²⁺, Na⁺, K⁺, Cl⁻, SO₄²⁻, NO₃⁻ and NH₄⁺ in the plains of southern South America, which encompass one of the most important agricultural basins an ...
DOI:
10.1007/s10533-019-00584-3

20. Changes in soil organic carbon and nutrient stocks in conventional selective logging versus reduced-impact logging in rainforests on highly weathered soils in Southern Cameroon

Author:
Tchiofo Lontsi, Rodine; Corre, Marife D.; van Straaten, Oliver; Veldkamp, Edzo
Source:
Forest ecology and management 2019
ISSN:
0378-1127
Subject:
chemical bases,   etc   ; Ferralsols; cation exchange capacity; exchangeable aluminum; felling; manganese; nutrients; pH; phosphorus; rain forests; roads; rocks; soil organic carbon; soil sampling; stable isotopes; total nitrogen; trees; Cameroon;     Show all 18 Subjects
Abstract:
... Although disturbances associated with selective logging can cause pronounced changes in soil characteristics and nutrient stocks, such information is very limited for highly weathered soils in Africa. We assessed the effects of reduced impact logging (RIL, with a 30-year rotation management plan) and conventional logging (CL, without a management plan) on physical and biochemical characteristics o ...
DOI:
10.1016/j.foreco.2019.117522