Chromatographic NMR spectroscopy: the effect of hollow silica microspheres on magnetic field inhomogeneities and resonance lineshapes

2020 ◽  
Vol 22 (37) ◽  
pp. 21383-21392
Author(s):  
Federico De Biasi ◽  
Federico Moro ◽  
Diego Frezzato ◽  
Federico Rastrelli
Keyword(s):  
Magnetic Field ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Line Broadening ◽  
Silica Microspheres ◽  
Hollow Silica

We provide a description of the line broadening phenomenon observed in chromatographic NMR spectra with hollow silica microspheres.

Studies on the interaction of selenite and selenium with sulphur donors. Part 5. Thiocyanate

1996 ◽  
Vol 74 (10) ◽  
pp. 1889-1895 ◽  
Author(s):  
Christopher Milne ◽  
John Milne
Keyword(s):  
Raman Spectroscopy ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Chemical Exchange ◽  
Acid Oxidation ◽  
Relaxation Processes ◽  
Line Broadening ◽  
Linkage Isomerism ◽  
Selenous Acid ◽  
Scalar Relaxation

The oxidation of thiocyanic acid by selenous acid has been shown to take place in an analogous way to that found for selenous acid oxidation of most thiols and thiolates to give the corresponding selenotrisulfide and disulfide products[Formula: see text]The products of this reaction have been studied by IR, Raman, and Se-77, C-13, and N-15 NMR spectroscopy. The vibrational spectra of the solid Se(SCN)2 have been assigned based on S-bonded thiocyanate ligands and, through NMR and vibrational spectroscopy, both this linkage isomer and the isomer with N- and S-bonded thiocyanate have been identified and characterized in solutions of Se(SCN)2. A complex combination of scalar relaxation processes, involving chemical exchange and quadrupolar effects, accounts for the line broadening observed in the carbon-13 NMR spectra. Key words: selenite, thiocyanate, selenium dithiocyanate, Se-77, N-15, and C-13 NMR; Raman spectroscopy; linkage isomerism

Synthesis of chloro(2-methylimidazole) ruthenium(III) complexes and their aqueous solution chemistry, and the crystal structure of [2-MeImH]2[RuCl52-MeIm]

2001 ◽  
Vol 79 (10) ◽  
pp. 1477-1482 ◽  
Author(s):  
Craig Anderson
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Solution Chemistry ◽  
Proton Nmr Spectroscopy ◽  
Line Broadening ◽  
Reaction Conditions ◽  
H Nmr ◽  
Paramagnetic Complexes

2-Methylimidazole (2-MeIm) reacts with RuCl3 in aqueous acidic ethanolic medium to give (2-MeImH)2[RuCl5(2-MeIm)] (1) and (2-MeImH)[RuCl4(2-MeIm)2] (2) (2-MeImH = protonated 2-methylimidazole), the ratio depending on reaction conditions used. Molecule 1 crystallizes in the space group Pnma: a = 14.046(2), b = 17.294(2), and c = 8.2778(12) Å. The 1H NMR spectra of these ruthenium(III) complexes have been measured and show peaks with large isotropic shifts and large line broadening characteristic of such paramagnetic complexes. The aquation of complexes 1 and 2 were followed by proton NMR spectroscopy. 1,2-Dimethyl imidazole (1,2-diMeIm) reacts with RuCl3 in methanolic solution to give [RuCl3(1,2-diMeIm)(H2O)S] (S=H2O (3a) or CH3OH (3b)). The aquation reactions of complexes 3a and 3b were followed by 1H NMR.Key words: ruthenium, paramagnetic, antitumour, NMR.

NMR spectroscopic investigation of p-substituted 2,4,4,6-tetraphenyl-1,4-dihydropyridines and their oxa and thia analogues

1989 ◽  
Vol 54 (7) ◽  
pp. 1854-1869 ◽  
Author(s):  
Marián Schwarz ◽  
Petr Trška ◽  
Josef Kuthan
Keyword(s):  
Nmr Spectroscopy ◽  
Trifluoroacetic Acid ◽  
Spectroscopic Investigation ◽  
Nmr Spectra ◽  
Dynamic Equilibrium

The 1H, 13C and 19F NMR spectra of photochromic p-substituted 2,4,4,6-tetraphenyl-1,4-dihydropyridines IIa-IIg, 1-methyl-2,4,4,6-tetraphenyl-1,4-dihydropyridines IIIa-IIIg, 2,4,4,6-tetraphenyl-4H-pyrans IVa-IVh, and 2,4,4,6-tetraphenyl-4H-thiopyran V were inspected; it was found that compounds IIa-IIg occur in a dynamic equilibrium with their dihydro tautomer VIa-VIg. Also deuteriodeprotonation of IIa and IIIa and their reaction with trifluoroacetic acid were investigated by NMR spectroscopy.

Unusual Rearrangement of Naphthalene in the Synthesis of a Novel B8-B8-Bridged Derivative in the [(1,2-C2B9H11)2-3-Co]- Series. X-Ray Structure and 11B NMR Spectra of [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- (CH3)4N+

1997 ◽  
Vol 62 (5) ◽  
pp. 746-751 ◽  
Author(s):  
Andreas Franken ◽  
Jaromír Plešek ◽  
Christiane Nachtigal
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Nucleophilic Substitution ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Unusual Rearrangement ◽  
Multinuclear Nmr Spectroscopy ◽  
11B Nmr ◽  
Isolated Compound

On treatment of the [(1,2-C2B9H11)2Co]- ion with naphthalene in presence of AlCl3 a remarkably bridged [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- ion is obtained as a single isolated compound. The triatomic -CH2-C9H6- bridge is derived from the rearranged naphthalene nucleus. The mechanism of this reaction is obscure but it does resemble the "Electrophile-Induced Nucleophilic Substitution" reported earlier. The structure of the compound was established by multinuclear NMR spectroscopy and by single crystal X-ray diffraction.

IR and 13C, 17O, and 119Sn NMR spectra of some bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids

1991 ◽  
Vol 56 (9) ◽  
pp. 1908-1915 ◽  
Author(s):  
Jaroslav Holeček ◽  
Antonín Lyčka ◽  
Milan Nádvorník ◽  
Karel Handlíř
Keyword(s):  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
Dicarboxylic Acid ◽  
Nmr Spectra ◽  
Dicarboxylic Acids ◽  
119Sn Nmr ◽  
Carboxylic Groups ◽  
Cyclic Oligomers ◽  
The Media ◽  
Oxygen Atoms

Infrared spectroscopy and multinuclear (13C, 17O, and 119Sn NMR spectroscopy have been used to study the structure of bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids (1-C4H9)2. Sn(X(COO)2), where X = (CH2)n (n = 0-8), CH=CH (cis and trans) and C6H4 (ortho and para).The crystalline compounds are formed by linear or cyclic oligomers or polymers whose basic building units represent a grouping composed of the central tin atom substituted by two 1-butyl groups and coordinated with both oxygen atoms of two anisobidentate carboxylic groups derived from different molecules of a dicarboxylic acid. The environment of the tin atom has a shape of a trapezoidal bipyramid. When dissolvet in non-coordinating solvents, the compounds retain the oligomeric character with unchanged structure of environment of the central tin atom. In the media of coordinating solvents the bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids form complexes whose central hexacoordinated tin atom binds two molecules of the solvent trough their donor atoms. Carboxylic groups form monodenate linkages in these complexes.

scholarly journals Mesoscopic simulations of the in situ NMR spectra of porous carbon based supercapacitors: Electronic structure and adsorbent reorganisation effects

2021 ◽  
Author(s):  
Anagha Sasikumar ◽  
Anouar Belhboub ◽  
Camille Bacon ◽  
Alexander C. Forse ◽  
John Griffin ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Nmr Spectroscopy ◽  
Molecular Species ◽  
Porous Carbon ◽  
Nmr Spectra ◽  
Charge Storage ◽  
In Situ Nmr Spectroscopy ◽  
In Situ Nmr ◽  
Carbon Based

In situ NMR spectroscopy is a powerful technique to investigate charge storage mechanisms in carbon-based supercapacitors thanks to its ability to distinguish ionic and molecular species adsorbed in the porous...

Two-dimensional NMR spectroscopy in Earth’s magnetic field

2006 ◽  
Vol 182 (2) ◽  
pp. 343-347 ◽  
Author(s):  
Jeremy N. Robinson ◽  
Andrew Coy ◽  
Robin Dykstra ◽  
Craig D. Eccles ◽  
Mark W. Hunter ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nmr Spectroscopy ◽  
Two Dimensional ◽  
Earth’S Magnetic Field ◽  
Earth's Magnetic Field

Investigation of radiofrequency induced release kinetics from magnetic hollow silica microspheres

2012 ◽  
Vol 159 ◽  
pp. 119-125 ◽  
Author(s):  
Pavel Kovačík ◽  
Zuzana Kremláčková ◽  
František Štěpánek
Keyword(s):  
Release Kinetics ◽  
Silica Microspheres ◽  
Hollow Silica

Application of ultra-high magnetic field for saccharide molecules: 1H NMR spectra of 6-O-α-d-glucopyranosyl-cyclomaltoheptaose and -cyclomaltohexaose

2005 ◽  
Vol 340 (7) ◽  
pp. 1343-1350 ◽  
Author(s):  
Yasuko Ishizuka ◽  
Kenji Takasugi ◽  
Yu Tsutsumi ◽  
Kenji Kanazawa ◽  
Tadashi Nemoto ◽  
...  
Keyword(s):  
Magnetic Field ◽  
1H Nmr ◽  
High Magnetic Field ◽  
Nmr Spectra ◽  
1H Nmr Spectra
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