1 H NMR investigation of the hetero-association of aromatic molecules in aqueous solution: factors involved in the stabilization of complexes of daunomycin and acridine drugs

2000 ◽  
Vol 98 (23) ◽  
pp. 1961-1971 ◽  
Author(s):  
David B. Davies, Dennis A. Veselkov, Veni
Keyword(s):  
Aqueous Solution ◽  
H Nmr ◽  
Aromatic Molecules

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

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, {Mo<sub>132</sub>} with chiral lactate ligands with the composition [Mo<sub>132</sub>O<sub>372</sub>(H<sub>2</sub>O)<sub>72</sub>(<i>x-</i>Lactate)<sub>30</sub>]<sup>42-</sup> (<i>x</i> = D or L), it was possible to study the interaction with a chiral guest, L/D-carnitine and (<i>R</i>/<i>S</i>)-2-butanol in aqueous solution. The enantioselective recognition was studied by quantitative <sup>1</sup>H NMR and <sup>1</sup>H 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 (K<i><sub>S</sub></i>/K<i><sub>R</sub></i> = 3) is observed for recognition within the capsule interior of (<i>R</i>)- and (<i>S</i>)-2-butanol.

scholarly journals Comparison of hydrogen atom and hydroxyl radical reactions with simple aromatic molecules in aqueous solution

2020 ◽  
Vol 534 ◽  
pp. 110754 ◽  
Author(s):  
Renáta Homlok ◽  
Viktória Mile ◽  
Erzsébet Takács ◽  
Gábor Járvás ◽  
Szabolcs Góger ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Atom ◽  
Hydroxyl Radical ◽  
Radical Reactions ◽  
Aromatic Molecules

scholarly journals NMR spectroscopic study of inclusion complexes of cetirizine dihydrochloride and β-cyclodextrin in solution

2007 ◽  
Vol 21 (3) ◽  
pp. 177-182 ◽  
Author(s):  
Syed Mashhood Ali ◽  
Santosh Kumar Upadhyay ◽  
Arti Maheshwari
Keyword(s):  
Aqueous Solution ◽  
Chemical Shift ◽  
Spectroscopic Study ◽  
Inclusion Complexes ◽  
Binding Constant ◽  
Spectroscopic Studies ◽  
Chemical Shift Change ◽  
Nmr Chemical Shift ◽  
H Nmr ◽  
Shift Change

Cetirizine dihydrochloride (CTZ), an antihistamine, forms two 1:1 inclusion complexes with β-cyclodextrin (β-CD) in aqueous solution as confirmed by detailed1H NMR, COSY and ROESY spectroscopic studies. The stoichiometry and overall binding constant of the complexes were determined by the treatment of1H NMR chemical shift change (Δδ) data. Most of the CTZ protons exhibited splitting in the presence of β-CD.

scholarly journals N,N'-(Hexane-1,6-diyl)bis(4-methyl-N-(oxiran-2-ylmethyl)benzenesulfonamide): Synthesis via cyclodextrin mediated N-alkylation in aqueous solution and further Prilezhaev epoxidation

2013 ◽  
Vol 9 ◽  
pp. 2834-2840 ◽  
Author(s):  
Julian Fischer ◽  
Simon Millan ◽  
Helmut Ritter
Keyword(s):  
Aqueous Solution ◽  
Allyl Bromide ◽  
Phase Transfer ◽  
2D Nmr ◽  
Phase Transfer Catalysts ◽  
H Nmr ◽  
Rheological Measurements

N-alkylation of N,N'-(hexane-1,6-diyl)bis(4-methylbenzenesulfonamide) with allyl bromide and subsequent Prilezhaev reaction with m-chloroperbenzoic acid to give N,N'-(hexane-1,6-diyl)bis(4-methyl-N-(oxiran-2-ylmethyl)benzenesulfonamide) is described. This twofold alkylation was performed in aqueous solution, whereby α-, and randomly methylated β-cyclodextrin were used as adequate phase transfer catalysts and the cyclodextrin–guest complexes were characterized by 1H NMR and 2D NMR ROESY spectroscopy. Finally, the curing properties of the diepoxide with lysine-based α-amino-ε-caprolactam were analyzed by rheological measurements.

Preparation of poly(methyl methacrylate) nano-latexes via UV irradiation in the presence of iron aqueous solution

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Hong Zhang ◽  
Limin Zang ◽  
Jiahe Luo ◽  
Jinshan Guo
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Glass Transition ◽  
Transition Temperature ◽  
Methyl Methacrylate ◽  
High Efficiency ◽  
Particle Sizes ◽  
H Nmr ◽  
Reaction Conversion ◽  
Emulsifying Agent

AbstractThe UV-initiated emulsion polymerization of methyl methacrylate (MMA) in the presence of FeCl3 was studied. The photopolymerization presented high efficiency even though using a small percentage of photoinitiator. The entire polymerization could be performed within 10 min and displayed a conversion higher than 90% at ambient temperature. The particle sizes could be tuned in the range of 20-90 nm. The effects of content of initiator and emulsifying agent upon the reaction conversion, distribution of molecular weight, diameter of particles and glass-transition temperature were examined. 1H-NMR technique was used to investigate the structural properties of PMMA.

Tautomerization tendencies of 2-acetylcycloalkanones, 2-acetyl-1,3-cycloalkanediones, and cyclic β-keto esters of five- and six-membered rings

2001 ◽  
Vol 79 (4) ◽  
pp. 448-454 ◽  
Author(s):  
Antonio Rojas ◽  
Alfonso Perez-Encabo ◽  
Ignacio Herraiz-Sierra ◽  
Carlos A Blanco
Keyword(s):  
Aqueous Solution ◽  
Rate Constants ◽  
Nmr Spectra ◽  
Tautomeric Equilibrium ◽  
Concentration Effects ◽  
Keto Esters ◽  
H Nmr ◽  
Kinetics Studies ◽  
Dilute Aqueous Solution ◽  
C Nmr

NMR and kinetics studies of the tautomeric equilibrium of 2-acetylcycloalkanones, 2-acetyl-1,3-cycloalkanediones, and methyl 2-oxocycloalkanecarboxylates of five- and six-membered rings have been carried out. By comparing 1H NMR and 13C NMR spectra recorded in D2O–DOCD3 and CDCl3, with those results derived using a bromination kinetic procedure in dilute aqueous solution, information concerning tautomeric interconversion is provided. Some discussions considering ionisation equilibria and rate constants involved have also been considered. Solvent and concentration effects on keto-enol equilibria have also been discussed.Key words: 2-acetylcycloalkanones, 2-acetyl-1,3-cycloalkanediones, methyl 2-oxocycloalkanecarboxylates, equilibrium, tautomerization, ionization.

sHigh resolution 1H nuclear magnetic resonance studies of a flavine and its product with MoCl4

1977 ◽  
Vol 55 (4) ◽  
pp. 575-582 ◽  
Author(s):  
T. Roberie ◽  
N. S. Bhacca ◽  
J. Selbin
Keyword(s):  
Aqueous Solution ◽  
Nuclear Magnetic Resonance ◽  
Binding Sites ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Side Chain ◽  
Magnetic Resonance Studies ◽  
H Nmr ◽  
Metal Atoms ◽  
1H Nuclear Magnetic Resonance

The high resolution 1H nmr spectra of the substituted flavine, 3-N-methyltetraacetylriboflavine (3-Me-TARF), and its non-aqueous solution complexes with Gd(fod)3, Eu(fod)3, MoCl4, and MoCl4•2CH3(CH2)2CN, were studied in order to try to discern the binding sites of the flavine as it attaches to the molybdenum. Evidence was found that all three metal atoms, Gd(III), Eu(III), and Mo(IV), are attached in solution not only by the primary binding (chelating) sites of the flavine, viz., the O-4 and N-5 atoms, but also by an acetyl oxygen atom, at the C-4′ site of the ribityl side chain. 300 MHz spectra of the 3-Me-TARF have permitted the coupling constants for the side chain methine and methylene protons to be obtained.

Dispersion of Boron Nitride Nanotubes in Aqueous Solution by Simple Aromatic Molecules

2014 ◽  
Vol 14 (4) ◽  
pp. 3028-3033 ◽  
Author(s):  
Dukeun Kim ◽  
Toshiki Sawada ◽  
Chunyi Zhi ◽  
Yoshio Bando ◽  
Dmitri Golberg ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Boron Nitride ◽  
Boron Nitride Nanotubes ◽  
Aromatic Molecules

Synthesis and vibrational study of a 1:1 stoichiometric complex of hydronium tetrafluoroborate and 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6)

1982 ◽  
Vol 60 (7) ◽  
pp. 853-861 ◽  
Author(s):  
Robert Chênevert ◽  
André Rodrigue ◽  
Marie Pigeon-Gosselin ◽  
Rodrigue Savoie
Keyword(s):  
Aqueous Solution ◽  
Transition Temperature ◽  
Crown Ether ◽  
Room Temperature ◽  
Organic Medium ◽  
Remarkable Property ◽  
H Nmr ◽  
Vibrational Study ◽  
Raman And Ir Spectroscopy ◽  
Stoichiometric Complex

The macrocyclic ether 1,4,7,10,13,16-hexaoxaoctadecane (18-crown-6) has the remarkable property of being able to transfer the hydronium (H3O+) ion from an aqueous solution to an organic medium. This property has been used to synthetize a 1:1 stoichiometric complex of this ether with hydronium tetrafluoroborate. This complex is very stable (mp 145 °C) and dissolves readily, without decomposition, in solvents such as CHCl3. The presence of the H3O+ and BF4− ions in the complex has been confirmed by chemical analysis, and by 1H nmr, Raman, and ir spectroscopy. The vibrational spectra indicate that a conformational change of the crown ether takes place in the complex over the temperature range −50 °C to −100 °C. The symmetry of the crown ether, which appears to be relatively high at room temperature, is considerably reduced below the transition temperature.

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