Synthesis and physicochemical properties of bolaamphiphiles from dimeric acid

The physicochemical behaviour of bolaamphiphile derivatives with an anionic, a cationic, or a non-ionic polar group and their mixtures is studied mainly by surface tension measurements, quasi-elastic light-scattering studies, 1H NMR spectroscopy, and surface monolayers. Bolaamphiphiles are synthesized by classical methods from a non-expensive mixture of α,ω-dicarboxylic acids, obtained by thermal Diels–Alder type cyclization of methyl 10-E,12-E linoleate, obtained from tall oil. The anionic and cationic bolaamphiphiles synthesized are water soluble and form stable monolayers when they are compressed. The anionic and the cationic bolaamphiphiles with an iodide atom as counter-anion show a behaviour between liquid-condensed and liquid-expanded. The other synthesized cationic bolaamphiphiles and the (1:1) mixtures of anionic–cationic bolaamphiphiles behave as liquid-condensed.

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Enantioselective Recognition of Chiral Guests by the Water-Soluble Chiral Keplerate {Mo132} Spherical Capsule with 30 Inner Lactate Ligands

10.26434/chemrxiv.8847923.v1 ◽

2019 ◽

Author(s):

Nancy Watfa ◽

Weimin Xuan ◽

Zoe Sinclair ◽

Robert Pow ◽

Yousef Abul-Haija ◽

...

Keyword(s):

Aqueous Solution ◽

Chiral Recognition ◽

Association Constants ◽

Water Soluble ◽

Enantioselective Recognition ◽

H Nmr ◽

Dosy Nmr ◽

Spherical Capsule ◽

Surface Pores ◽

Guest Chemistry

Investigations of chiral host guest chemistry are important to explore recognition in confined environments. Here, by synthesizing water-soluble chiral porous nanocapsule based on the inorganic metal-oxo Keplerate-type cluster, {Mo132} with chiral lactate ligands with the composition [Mo132O372(H2O)72(x-Lactate)30]42- (x = D or L), it was possible to study the interaction with a chiral guest, L/D-carnitine and (R/S)-2-butanol in aqueous solution. The enantioselective recognition was studied by quantitative 1H NMR and 1H DOSY NMR which highlighted that the chiral recognition is regulated by two distinct sites. Differences in the association constants (K) of L- and D-carnitine, which, due to their charge, are generally restricted from entering the interior of the host, are observed, indicating that their recognition predominantly occurs at the surface pores of the structure. Conversely, a larger difference in association constants (KS/KR = 3) is observed for recognition within the capsule interior of (R)- and (S)-2-butanol.

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Polar Diels-Alder Reactions Under Microwave Irradiation Employing Different Heterocyclic Compounds as Electrophiles

Mini-Reviews in Organic Chemistry ◽

10.2174/1570193x15666180608083925 ◽

2019 ◽

Vol 16 (6) ◽

pp. 527-543 ◽

Cited By ~ 1

Author(s):

Pedro M.E. Mancini ◽

Carla M. Ormachea ◽

María N. Kneeteman

Keyword(s):

Organic Synthesis ◽

Heterocyclic Compounds ◽

Ionic Conduction ◽

Theoretical Calculations ◽

Cycloaddition Reaction ◽

Diels Alder ◽

The Other ◽

Conventional Heating ◽

Protic Ionic Liquids ◽

Solvent Free Conditions

During the last twenty years, our research group has been working with aromatic nitrosubstituted compounds acting as electrophiles in Polar Diels-Alder (P-DA) reactions with different dienes of diverse nucleophilicity. In this type of reaction, after the cycloaddition reaction, the nitrated compounds obtained as the [4+2] cycloadducts suffer cis-extrusion with the loss of nitrous acid and a subsequent aromatization. In this form, the reaction results are irreversible. On the other hand, the microwave-assisted controlled heating become a powerful tool in organic synthesis as it makes the reaction mixture undergo heating by a combination of thermal effects, dipolar polarization and ionic conduction. As the Diels-Alder (D-A) reaction is one of the most important process in organic synthesis, the microwave (MW) irradiation was applied instead of conventional heating, and this resulted in better yields and shorter reaction times. Several substituted heterocyclic compounds were used as electrophiles and different dienes as nucleophiles. Two experimental situations are involved: one in the presence of Protic Ionic Liquids (PILs) as solvent and the other under solvent-free conditions. The analysis is based on experimental data and theoretical calculations.

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Measurement of δ18O and δ2H of water and ethanol in wine by Off-Axis Integrated Cavity Output Spectroscopy and Isotope Ratio Mass Spectrometry

European Food Research and Technology ◽

10.1007/s00217-021-03758-2 ◽

2021 ◽

Author(s):

Xing Wang ◽

Henk G. Jansen ◽

Haico Duin ◽

Harro A. J. Meijer

Keyword(s):

Mass Spectrometry ◽

Isotope Ratio ◽

Isotope Analysis ◽

Isotope Ratio Mass Spectrometry ◽

Growth Conditions ◽

The Other ◽

H Nmr ◽

Cavity Output ◽

Pre Treatment ◽

Output Laser

AbstractThere are two officially approved methods for stable isotope analysis for wine authentication. One describes δ18O measurements of the wine water using Isotope Ratio Mass Spectrometry (IRMS), and the other one uses Deuterium-Nuclear Magnetic Resonance (2H-NMR) to measure the deuterium of the wine ethanol. Recently, off-axis integrated cavity output (laser) spectroscopy (OA-ICOS) has become an easier alternative to quantify wine water isotopes, thanks to the spectral contaminant identifier (SCI). We utilized an OA-ICOS analyser with SCI to measure the δ18O and δ2H of water in 27 wine samples without any pre-treatment. The OA-ICOS results reveal a wealth of information about the growth conditions of the wines, which shows the advantages to extend the official δ18O wine water method by δ2H that is obtained easily from OA-ICOS. We also performed high-temperature pyrolysis and chromium reduction combined with IRMS measurements to illustrate the “whole wine” isotope ratios. The δ18O results of OA-ICOS and IRMS show non-significant differences, but the δ2H results of both methods differ much more. As the δ2H difference between these two methods is mainly caused by ethanol, we investigated the possibility to deduce deuterium of wine ethanol from this difference. The results present large uncertainties and deviate from the obtained 2H-NMR results. The deviation is caused by the other constituents in the wine, and the uncertainty is due to the limited precision of the SCI-based correction, which need to improve to obtain the 2H values of ethanol as alternative for the 2H-NMR method.

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Water-soluble β-aminobisulfonate building blocks for pH and Cu2+ indicators

RSC Advances ◽

10.1039/c6ra17791c ◽

2016 ◽

Vol 6 (88) ◽

pp. 84712-84721 ◽

Cited By ~ 5

Author(s):

Maria A. Cardona ◽

Marina Kveder ◽

Ulrich Baisch ◽

Michael R. Probert ◽

David C. Magri

Keyword(s):

Nmr Spectroscopy ◽

Building Blocks ◽

Water Soluble ◽

Visible Absorption ◽

H Nmr ◽

Uv Visible

Two phenyl β-aminobisulfonate ligands characterised by UV-visible absorption, EPR and 1H NMR spectroscopy exhibit evidence for binding with Cu2+ in water and methanol.

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CO-ORDINATION COMPLEXES OF TITANIUM (IV) HALIDES: II. PREPARATION AND INFRARED SPECTRA OF THE COMPLEXES OF TITANIUM TETRACHLORIDE WITH DIESTERS OF α,ω-DICARBOXYLIC ACIDS AND COMPARISON WITH ANALOGOUS COMPLEXES OF ZIRCONIUM TETRACHLORIDE AND TIN TETRACHLORIDE

Canadian Journal of Chemistry ◽

10.1139/v61-312 ◽

1961 ◽

Vol 39 (11) ◽

pp. 2343-2352 ◽

Cited By ~ 12

Author(s):

Ernest Rivet ◽

Real Aubin ◽

Roland Rivest

Keyword(s):

Molecular Weight ◽

Infrared Spectra ◽

Titanium Tetrachloride ◽

Complex Molecule ◽

Dicarboxylic Acids ◽

The Other ◽

Zirconium Tetrachloride ◽

Melting Points ◽

Zirconium Complexes ◽

Tin Tetrachloride

Co-ordination complexes between diesters of α,ω-dicarboxylic acids and titanium tetrachloride, tin tetrachloride, and zirconium tetrachloride have been prepared. The analytical results, the infrared spectra, the melting points, and the molecular-weight determinations indicate that for the titanium and zirconium complexes, two types of complexes are obtained, one having a general formula MX4•1 diester in which chelate rings from five to nine atoms are formed and the other one, 2MX4•1 diester in which there are two 4-membered rings per complex molecule. With tin tetrachloride only one type of complex is formed, which has two tin tetrachlorides and two diesters per complex molecule.

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Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.12.54 ◽

2016 ◽

Vol 12 ◽

pp. 549-563 ◽

Cited By ~ 3

Author(s):

Vito Rizzi ◽

Sergio Matera ◽

Paola Semeraro ◽

Paola Fini ◽

Pinalysa Cosma

Keyword(s):

Inclusion Complexes ◽

Pyrimidine Ring ◽

Protective Role ◽

Supramolecular Structures ◽

Water Soluble ◽

Aqueous Environment ◽

Spectroscopic Techniques ◽

Guest Molecules ◽

H Nmr ◽

Cv Measurements

Since several years the inclusion of organic compounds (guests) within the hydrophobic cavity (host) of cyclodextrins (CDs) has been the subject of many investigations. Interestingly, the formation of inclusion complexes could affect the properties of the guest molecules and, for example, the influence of the delivery system can be a method to improve/change the photochemical behavior of the guest. In particular, very recent studies have shown the protective role of CDs preventing the degradation of the encapsulated guest. Starting from this consideration, in this work, only the structure and complexation mode of the inclusion complexes involving 4-thiothymidine (S4TdR, a known photosensitizer) and five CDs, namely 2-hydroxypropyl-α-cyclodextrin (2-HP-α-CD), 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD), 2-hydroxypropyl-γ-cyclodextrin (2-HP-γ-CD), heptakis-(2,6-di-O-methyl)-β-cyclodextrin (DIMEB CD) and heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (TRIMEB CD) were investigated by different spectroscopic techniques (UV–vis, FTIR–ATR, 1H NMR) and cyclic voltammetry analysis (CV). This work is necessary for a prospective research on the photoreactivity of S4TdR in aqueous environment and in the presence of CDs to prevent its degradation under irradiation. UV–vis, FTIR–ATR and CV measurements suggested the formation of supramolecular structures involving the employed CDs and mainly the pyrimidine ring of S4TdR. 1H NMR analyses confirmed such indication, unveiling the presence of inclusion complexes. The strongest and deepest interactions were suggested when TRIMEB and DIMEB CDs were studied. The S4TdR affinity towards CDs was also evaluated by using the Benesi–Hildebrand (B–H) equation at 25 °C employing CV and 1H NMR methods. The stoichiometry of the interaction was also inferred and it appears to be 1:1 for all examined CDs.

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Synthesis of perialkynylated tetrapyrazinoporphyrazines and its Optical Properties

Journal of Chemical Research ◽

10.3184/030823409x449473 ◽

2009 ◽

Vol 2009 (5) ◽

pp. 312-316 ◽

Cited By ~ 3

Author(s):

Chun Keun Jang ◽

Jae Yun Jaung

Keyword(s):

Optical Properties ◽

Nmr Spectroscopy ◽

Laser Desorption ◽

Diels Alder ◽

Visible Spectroscopy ◽

H Nmr ◽

Uv Visible ◽

Tof Ms ◽

Matrix Assisted Laser ◽

Matrix Assisted Laser Desorption

Some phthalocyanines soluble in organic solvents have been developed by peripheral introduction of substituent groups. We report a new method for preparation of the polyphenyl-substituted dicyanopyrazines based on the [2 + 4] Diels-Alder cycloaddition of the tetraphenylcyclopentadienone to an ethynyl compound. The synthesised tetrapyrazinoporphyrazinato metal complexes were characterised by UV-visible spectroscopy, MALDI-TOF-Ms (matrix-assisted laser desorption ionisation time-of-flight mass) spectroscopy, and 1H NMR spectroscopy.

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Identification of Australian barley cultivars by laboratory methods: gel electrophoresis and gel isoelectric focusing of the endosperm proteins

Australian Journal of Experimental Agriculture ◽

10.1071/ea9771020 ◽

1977 ◽

Vol 17 (89) ◽

pp. 1020 ◽

Cited By ~ 15

Author(s):

J McCausland ◽

CW Wrigley

Keyword(s):

Isoelectric Focusing ◽

Gel Electrophoresis ◽

Water Soluble ◽

The Other ◽

Starch Gel Electrophoresis ◽

Laboratory Methods ◽

Barley Cultivars ◽

Starch Gel ◽

Electrophoretic Techniques ◽

Gel Isoelectric Focusing

A range of laboratory methods was examined for their ability to distinguish between 19 barley cultivars currently grown in Australia. Aleurone colour, revealed after mechanical or chemical dehulling, differentiated Abyssinian, Atlas, Cape and Corvette from the other cultivars. Peroxidase and phenol testing were not useful. Seven different patterns were obtained for the hordeins of lowest mobility by starch gel electrophoresis. Further distinction was provided by flat gel isoelectric focusing of the water-soluble and hordein proteins for which 13 different pattern-groupings were obtained. The two electrophoretic techniques complemented one another, so that the use of both methods left only a few cultivars that could not be distinguished.

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Contrasting signatures of the sources and types of aerosols in the western and eastern Himalayas: Radiative implications

10.5194/egusphere-egu21-5916 ◽

2021 ◽

Author(s):

Arun Bs ◽

Mukunda Gogoi ◽

Prashant Hegde ◽

Suresh Babu

Keyword(s):

Mineral Dust ◽

Water Soluble ◽

The Other ◽

Anthropogenic Source ◽

Chemical Compositions ◽

Eastern Himalayas ◽

Chemical Aging ◽

Other Hand ◽

Secondary Formation ◽

The Impact

The rapid changes in the pattern of atmospheric warming over the Himalayas, along with severe degradation of Himalayan glaciers in recent years suggest the inevitability of accurate source characterization and quantification of the impact of aerosols on the Himalayan atmosphere and snow. In this regard, extensive study of the chemical compositions of aerosols at two distinct regions, Himansh (32.4&#7484;N, 77.6&#7484;E, ~ 4080 m a.s.l) and Lachung (27.4&#7484;N, 88.4&#7484;E, ~ 2700 m a.s.l), elucidates distinct signatures of the sources and types of aerosols prevailing over the western and eastern parts of Himalayas. The mass-mixing ratios of water-soluble (Na+, NH4+, K+, Ca2+, Mg2+, Cl-, SO42-, NO3-, MSA-, C2O42-), carbonaceous (EC, OC, WSOC) and selected elemental (Al, Fe, Cu, Cr, Ti) species depicted significant abundance of mineral dust aerosols (~ 67%), along with a significant contribution of carbonaceous aerosols (~ 9%) during summer to autumn (August-October) over the western Himalayan site. On the other hand, the eastern Himalayan site is found to be dominant of OC (~ 53% in winter) followed by SO42- (as high as 37% in spring) and EC (8-12%) during August to February. However, OC/EC and WSOC/OC ratios showed significantly higher values over both the sites (~ 12.5, and 0.56 at Himansh; ~ 5.7 and ~ 0.74 at Lachung) indicating the secondary formation of organic aerosols via chemical aging over both the sites. The enrichment factors estimated from the concentrations of trace elements over the western Himalayan site revealed the influence of anthropogenic source contribution from the regional hot-spots of Indo-Gangetic Plains, in addition to that of west Asia and the Middle East countries. On the other hand, the source apportionment of aerosols (based on positive matrix factorization - PMF model) over the eastern Himalayas demonstrated the biomass-burning aerosols (25.94%), secondary formation of aerosols via chemical aging (15.94%), vehicular and industrial emissions (20.54%), primary emission sources associated with mineral dust sources (22.28%) and aged secondary aerosols (15.31%) as the major sources of aerosols. Due to abundant anthropogenic source impacts at the eastern Himalayan site, the atmospheric forcing is most elevated in winter (13.4 &#177; 4.4 Wm-2), which is more than two times the average values seen at the western Himalayan region during the study period. The heavily polluted eastern part of the IGP is a potential anthropogenic source region contributing to the aerosol loading at the eastern Himalayas. These observations have far-reaching implications in view of the role of aerosols on regional radiative balance and their impact on snow/glacier coverage.

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THE OXIDATION OF ESTRONE-16-C14BY PEROXIDASE

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y62-054 ◽

1962 ◽

Vol 40 (1) ◽

pp. 459-469 ◽

Cited By ~ 3

Author(s):

P. H. Jellinck ◽

Louise Irwin

Keyword(s):

Amino Acids ◽

Hydrogen Peroxide ◽

Amino Acid ◽

Serum Albumin ◽

Oxidase Activity ◽

Water Soluble ◽

The Other ◽

Aerobic Incubation ◽

Nitrogenous Compounds ◽

Initial Generation

Aerobic incubation of estrone-16-C14with peroxidase in the presence of serum albumin and other proteins resulted in the formation of water-soluble, ether-insoluble metabolites in high percentage yields. Similar products were formed when protein was replaced by cysteine or tryptophan but none of the other amino acids tested had any effect. The evidence points to an initial generation of hydrogen peroxide from these nitrogenous compounds by the enzyme acting as an aerobic oxidase, and the subsequent peroxidation of estrone to highly reactive products. These then combine with the protein or amino acid or else undergo alternative reactions. A strong chemical bond is formed with albumin and attempts to release the estrone metabolites from it were unsuccessful. Uterine homogenates from estrogen-treated rats showing high DPNH oxidase activity contained no "peroxidase" as measured by the formation of water-soluble products from estrone in the presence of protein.

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