Correlations between proton chemical shift tensors, deuterium quadrupole couplings, and bond distances for hydrogen bonds in solids

1980 ◽  
Vol 73 (5) ◽  
pp. 2037-2043 ◽  
Author(s):  
Bo Berglund ◽  
Robert W. Vaughan
Keyword(s):  
Chemical Shift ◽  
Hydrogen Bonds ◽  
Proton Chemical Shift ◽  
Chemical Shift Tensors

Proton chemical shift tensors in neutral and ionic OH⋯O hydrogen bonds

1982 ◽  
Vol 86 (4) ◽  
pp. 380-383 ◽  
Author(s):  
Celeste McMichael Rohlfing ◽  
Leland C. Allen ◽  
Robert Ditchfield
Keyword(s):  
Chemical Shift ◽  
Hydrogen Bonds ◽  
Proton Chemical Shift ◽  
Chemical Shift Tensors

scholarly journals Temperature-Dependent Solid-State NMR Proton Chemical-Shift Values and Hydrogen Bonding

2021 ◽  
Author(s):  
Alexander A. Malär ◽  
Laura A. Völker ◽  
Riccardo Cadalbert ◽  
Lauriane Lecoq ◽  
Matthias Ernst ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Chemical Shift ◽  
Hydrogen Bonds ◽  
Solid State Nmr ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Proton Chemical Shift ◽  
Temperature Dependent

Temperature-dependent NMR experiments are often complicated by rather long magnetic-field equilibration times, for example occurring upon a change of sample temperature. We demonstrate that the fast temporal stabilization of the magnetic field can be achieved by actively stabilizing the temperature which allows to quantify the weak temperature dependence of the proton chemical shift which can be diagnostic for the presence of hydrogen bonds. Hydrogen bonding plays a central role in molecular recognition events from both fields, chemistry and biology. Their direct detection by standard structure determination techniques, such as X-ray crystallography or cryo-electron microscopy, remains challenging due to the difficulties of approaching the required resolution, on the order of 1 Å. We herein explore a spectroscopic approach using solid-state NMR to identify protons engaged in hydrogen bonds and explore the measurement of proton chemical-shift temperature coefficients. Using the examples of a phosphorylated amino acid and the protein ubiquitin, we show that fast Magic-Angle Spinning (MAS) experiments at 100 kHz yield sufficient resolution in proton-detected spectra to quantify the rather small chemical-shift changes upon temperature variations.<br>

scholarly journals H/D Isotope Effects on 1H-NMR Chemical Shifts in Cyclic Heterodimers and Heterotrimers of Phosphinic and Phosphoric Acids

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1907 ◽  
Author(s):  
Valeriia V. Mulloyarova ◽  
Daria O. Ustimchuk ◽  
Aleksander Filarowski ◽  
Peter M. Tolstoy
Keyword(s):  
Chemical Shift ◽  
Low Temperature ◽  
Hydrogen Bonds ◽  
1H Nmr ◽  
31P Nmr ◽  
Chemical Shifts ◽  
Isotope Effects ◽  
Proton Chemical Shift ◽  
Steric Factors ◽  
Solvent Formation

Hydrogen-bonded heterocomplexes formed by POOH-containing acids (diphenylphosphoric 1, dimethylphosphoric 2, diphenylphosphinic 3, and dimethylphosphinic 4) are studied by the low-temperature (100 K) 1H-NMR and 31P-NMR using liquefied gases CDF3/CDF2Cl as a solvent. Formation of cyclic dimers and cyclic trimers consisting of molecules of two different acids is confirmed by the analysis of vicinal H/D isotope effects (changes in the bridging proton chemical shift, δH, after the deuteration of a neighboring H-bond). Acids 1 and 4 (or 1 and 3) form heterotrimers with very strong (short) H-bonds (δH ca. 17 ppm). While in the case of all heterotrimers the H-bonds are cyclically arranged head-to-tail, ···O=P–O–H···O=P–O–H···, and thus their cooperative coupling is expected, the signs of vicinal H/D isotope effects indicate an effective anticooperativity, presumably due to steric factors: when one of the H-bonds is elongated upon deuteration, the structure of the heterotrimer adjusts by shortening the neighboring hydrogen bonds. We also demonstrate the formation of cyclic tetramers: in the case of acids 1 and 4 the structure has alternating molecules of 1 and 4 in the cycle, while in case of acids 1 and 3 the cycle has two molecules of 1 followed by two molecules of 3.

Proton chemical shift tensors in hydrogen‐bonded dimers of RCOOH and ROH

1983 ◽  
Vol 79 (10) ◽  
pp. 4958-4966 ◽  
Author(s):  
Celeste McMichael Rohlfing ◽  
Leland C. Allen ◽  
Robert Ditchfield
Keyword(s):  
Chemical Shift ◽  
Proton Chemical Shift ◽  
Chemical Shift Tensors ◽  
Hydrogen Bonded
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