Nuclear magnetic resonance spectroscopy amines

Instmmental methods of analysis provide information about the specific composition and purity of the amines. QuaUtative information about the identity of the product (functional groups present) and quantitative analysis (amount of various components such as nitrile, amide, acid, and deterruination of unsaturation) can be obtained by infrared analysis. Gas chromatography (gc), with a Hquid phase of either Apiezon grease or Carbowax, and high performance Hquid chromatography (hplc), using siHca columns and solvent systems such as isooctane, methyl tert-huty ether, tetrahydrofuran, and methanol, are used for quantitative analysis of fatty amine mixtures. Nuclear magnetic resonance spectroscopy (nmr), both proton ( H) and carbon-13 ( C), which can be used for quaHtative and quantitative analysis, is an important method used to analyze fatty amines (8,81). 

The tautomerism of 2- and 3-aminothiophenes was mentioned by Hartough in his review of thiophenes/ but the first definite evidence became available in 1961 when Hoffman and Gronowitz showed conclusively by nuclear magnetic resonance spectroscopy that these compounds both exist in the amino form. In agreement with this finding, 3-aminothiophene generally behaves as an aromatic amine. ... 

Nuclear magnetic resonance spectroscopy for /V-acyloxy-/V-alkoxyamides 13C NMR spectroscopy, 56-58 15N NMR spectroscopy, 58-59 dynamic 1H NMR spectroscopy, 59 Nucleophilic substitution (SN2) reactions, /V-acyloxy-/V-alkoxyamidcs, 70-90 alcoholysis reactions, 89-90 with aromatic amines, HERON reactions, 70-74... 

Duthaler, R.O. and Roberts, J.D., Nitrogen-15 nuclear magnetic resonance spectroscopy solvent effects on the 15N chemical shifts of saturated amines and their hydrochlorides, J. Magn. Reson., 34, 129, 1979. 

Evidence for the interaction between tributylamine and BN nanotubes has been obtained by nuclear magnetic resonance spectroscopy. We have studied the H and 13C NMR spectra of tributylamine-functionalized BN nanotubes in comparison with the spectra of tributylamine. We observe a small increase in the H chemical shift by 0.02 ppm in the amine-BN adduct. In the case of nC NMR spectra, we observe a significant increase in the chemical shifts of the y and S carbons by 0.4 ppm and a decrease in the chemical shift of the P carbon atom by 0.3 ppm. The chemical shift of the acarbon is also higher in the amine-BN adduct by 0.1 ppm. The changes in the H and L1C spectra of tributylamine found on interaction with BN are comparable to those reported in the literature for similar complexes.17,18... 

Numerous adducts of the halides AX3 with, for example, tertiary amines or arsines are reported in the literature, but these will not be considered here. Decomposition reactions occur with primary or secondary amines (65, 140). The compound 2AsF3-3S03 (45), which is formed from AsF3 and S03, has a complicated structure that has been elucidated by nuclear magnetic resonance spectroscopy (58). 

Nuclear Magnetic Resonance Spectroscopy. - A study of protonation-induced shifts in the n.m.r. spectra of cyclic amines includes work with the... 

Nuclear Magnetic Resonance Spectroscopy.—As noted above, conformational analysis of bicyclo[3.3.1]nonanes is still a topic of considerable interest. A variable-temperature n.m.r. analysis now provides the first case in which the boat-chair-chair-boat equilibrium is directly observed in the amines (17) and (18). In a related case, re-examination of the acetal (19) suggests that the preferred conformation involves a chair carbocyclic ring and a boat heterocyclic ring. This conclusion was made by n.m.r. analysis, using lanthanide shift reagents, by a study of nuclear Overhauser effects, and by measurement of relaxation times of protons. Details have been reported for other 3-azabicyclo[3.3.1]nonanes, and the non-additivity of substituent effects on chemical shifts in 9-thiabicyclo[3.3.1]non-2-enes has been analysed. Both and n.m.r. data have been reported for a series of 9-borabicyclo[3.3.1]non-anes and their pyridine complexes. 

Amines - Spectra. 2. Alkaloids — Spectra. 3. Carbon - Isotopes — Spectra. 4. Nuclear magnetic resonance spectroscopy. I. Hindenlang, David M., joint author, n. Title. 

Fischer H, Gyllenhaal O, Vessmann J, Albert K (2003) Reaction monitming of aliphatic amines in supercritical carbon dioxide by proton nuclear magnetic resonance spectroscopy and implications for supercritical fluid chromatography. Anal Chem 75 622-626... 

Infrared spectroscopy helps to differentiate between primary and secondary amines. Nuclear magnetic resonance spectroscopy indicates the presence of nitrogen-bound hydrogens both hydrogen and carbon atoms are deshielded in the vicinity of the nitrogen. Mass spectra are... 

Nuclear magnetic resonance (nmr) spectroscopy is useful for determining quaternary stmcture. The N-nmr can distinguish between quaternary ammonium compounds and amines, whether primary, secondary, or tertiary, as well as provide information about the molecular stmcture around the nitrogen atom. The C-nmr can distinguish among oleic, tallow, and hydrogenated tallow sources (194). 

Several methods are available in the literature for the measurement of aliphatic amines in biological samples [28]. Problems with specificity and separation and cumbersome derivatisation and/or extraction procedures have limited the use of these techniques on a larger scale in clinical practice. The lack of a simple analytical method may have led to an underestimation of the incidence of the fish odour syndrome. For diagnosing the syndrome, an analytical technique should be used that is able to simultaneously and quantitatively measure TMA and its N-oxide in the complex matrix of human urine. Two such methods are currently available for this purpose proton nuclear magnetic resonance (NMR) spectroscopy and head-space gas analysis with gas chromatography or direct mass spectrometry (see below). 

In this Sect, we describe the starting material impurities and their effect on the processing and cure reactions of TGDDM-DDS epoxies. The cure reactions are characterized by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) studies. The BF3 amine catalysts used to accelerate the cure of TGDDM-DDS epoxies are characterized by nuclear magnetic resonance (NMR) spectroscopy studies. 

Abstract—The nature of the product of the reaction between an aminated silane and carbon dioxide was re-examined with the aid of simple model compounds, several amines, and several aminosilanes. Since the reaction products previously proposed include the amine bicarbonate and a carbamate derived from the amine, ammonium bicarbonate and ammonium carbamate were studied as models for the anions. Carbon dioxide adducts of neat model amines were prepared and studied. Results from a variety of techniques are summarized. Among the most useful was Fourier transform infrared (FTIR) spectroscopy of fluorolube mulls. FTIR spectra were distinctive and assignments characteristic of the two species were extracted from the spectral data. Comparisons of these assignments with the products of the reaction between carbon dioxide and various amines were made. The results indicate that alkylammonium carbamates are the principal product. Nuclear magnetic resonance (NMR) spectra in D20 indicated much dissociation and were not helpful in defining the products. 

Certain functional groups in a molecule (e.g., hydroxyl, carbonyl, and amine) absorb IR radiation and exhibit absorption bands at characteristic frequencies regions regardless of the structure of the rest of the molecule. These bands are termed group frequencies. They are predictable and allow the analyst to deduce important structural information about an unknown molecule. An IR spectrum can be rapidly recorded for any phase, i.e., solid, liquid, or vapor. By coupling IR spectroscopy with other analytical techniques such as nuclear magnetic resonance (NMR)... 

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