Quadrupolar relaxation effects in methyl-substituted ammonium ions as determined by 1H nuclear magnetic resonance

1985 ◽  
Vol 63 (11) ◽  
pp. 2975-2978 ◽  
Author(s):  
James D. Halliday ◽  
Patrick E. Bindner ◽  
Shahsultan Padamshi
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectra ◽  
Ammonium Ions ◽  
Quadrupole Interactions ◽  
Relaxation Effects ◽  
1H Nuclear Magnetic Resonance ◽  
Quadrupolar Relaxation ◽  
Magnetic Resonances ◽  
Hcl Solution ◽  
Nuclear Magnetic

Nitrogen-14 quadrupole interactions broaden the 1H nuclear magnetic resonances of the ammonium protons spin-coupled to 14N in the methyl-substituted ammonium chlorides (methylammonium, dimethylammonium, and trimethylammonium). These proton lineshapes have been determined over the temperature range −8.3 to +93.6 °C in 6 mol L−1 aqueous HCl solution. The 14N spin-lifetimes, τ, have been calculated from the Arrhenius form equation In τ vs. 1/T (K), and yield activation energies of 10.63 ± 0.92, 10.60 ± 0.52, and 11.12 ± 0.39 kJ mol−1 for the mono-, di-, and tri-methyl species, respectively. The 14N nmr linewidths have been extracted from these data and a comparison is made with 14N nmr spectra obtained by Ogg and Ray.

Quadrupolar interactions in amines as determined by 1H nuclear magnetic resonance: mono- and dimethylamines

1984 ◽  
Vol 62 (7) ◽  
pp. 1258-1261 ◽  
Author(s):  
James D. Halliday ◽  
Patrick E. Bindner ◽  
Shahsultan Padamshi
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nmr Spectra ◽  
Molecular Reorientation ◽  
Correlation Times ◽  
Temperature Range ◽  
H Nmr ◽  
Quadrupole Interactions ◽  
1H Nuclear Magnetic Resonance ◽  
Temperature Activation

Nitrogen-14 quadrupole interactions have been observed in the nonexchanging amino proton 1H nmr spectra of rigorously purified liquid mono- and dimethylamines over the temperature range −82 °C to +81 °C. The proton lineshapes have been analyzed to yield 14N spin-lifetimes (τ) as a function of temperature. Activation energies and correlation times for molecular reorientation in the liquids have been calculated from these data and the results compared with those from 14N nmr measurements.

scholarly journals P052 Nuclear magnetic resonance metabolomic profiling of IBD patients under anti-TNF treatment. Are the pathways network deregulated?

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S160-S160
Author(s):  
S Notararigo ◽  
M Martin-Pastor ◽  
J E Dominguez Munoz ◽  
M Barreiro-de Acosta
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nmr Spectra ◽  
Mononuclear Cells ◽  
High Rate ◽  
Resonance Spectroscopy ◽  
Serum Samples ◽  
Spectral Window ◽  
Metabolomic Study ◽  
Nuclear Magnetic

Abstract Background The deregulation of immune system cell response implies loss of T-cell apoptosis, high rate of proinflammatory cytokines production and subsequent exacerbate activation of TNF-α pathway. The use of biologic antibody decrease inflammation rate and symptoms, but it remains unclear if it has a direct effect on the pathways activation/inactivation on peripheral blood mononuclear cells (PBMCs). The aim of this study is evaluate the role of nuclear magnetic resonance spectroscopy (NMR) applied to the metabolomic study of serum samples isolated from fresh blood from inflammatory bowel disease (IBD) patients under IFX treatment to understand the activated/inactivated pathways of PBMCs. Methods A case–control study was performed. Inclusion criteria were IBD patients under IFX treatment. Blood samples were obtained in Crohn’s disease (CD) and ulcerative colitis (UC) patients before IFX and in healthy controls (CTRL). CD patients were divided into subgroups according to the gut affected, in Ileocolic (IC), ileum and colon. NMR samples of the serum were collected and measured according to Standard Operation Procedures. Three types of NMR spectra were measured for each serum sample (1Hnoepresat, 1Hcpmgpresat and 1HDfilterpresat). The signal in each NMR spectrum was integrated in a series of equidistant little portion of the spectrum called buckets of a constant width of 0.04 ppm, covering the complete 1H NMR spectral window from −5 to 14 ppm. Buckets in regions depleted from signal at the two extremes of the spectrum were discarded as well as those in the proximity of the water peak at ca. 4.7 ppm which was affected by the presaturation. The vectors corresponding to a number of samples of two or more groups can be rapidly analysed using Multivariant Statistical Analysis methods. Results Twenty-two IBD patients (12 CD and nine UC) were included, 10 CTRL were also included. The metabolomic analyses of the NMR spectra of the serum of the different patients and control groups by the fingerprinting and targeting profiling strategies provided OPLS-DA statistical models (Figure 1) that permitted the successful classification of certain groups of samples which are summarised in Table 1. Conclusion The results of this pilot NMR metabolomic study of serum samples of IBD found a series of spectral fingerprints that are able to discriminate between groups of patients CTRL and CD, which underlines its potential use for the diagnosis of the disease.

The metal nuclear magnetic resonance spectra of some tin(II) and lead(II) complexes with polydentate phosphines

1983 ◽  
Vol 61 (8) ◽  
pp. 1795-1799 ◽  
Author(s):  
Philip A. W. Dean
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nmr Spectra ◽  
Narrow Range ◽  
Chemical Shifts ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The previously reported 1:1 complexes formed in MeNO2, between M(SbF6)2 (M = Sn or Pb) and Ph2P(CH2)2PPh2, PhP[(CH2)2PPh2]2, MeC(CH2PPh2)3, P[(CH2)2PPh2]3, and [Formula: see text] have been studied by metal (119Sn or 207Pb) nmr. The metal chemical shifts span the comparatively narrow range of −586 to −792 ppm and 60 to −269 ppm, relative to the resonance of MMe4, for 119Sn and 207Pb nmr, respectively. The implications of these data regarding the denticity of the ligand in M(P[(CH2)2PPh2]3)2+ are discussed, and a comparison with the metal nmr spectra of related stannous and plumbous complexes is made.

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