Structure-dependent intermolecular hydrogen-bond effects on carbon-13 NMR chemical shifts in enol forms of 1,3-diketones

1987 ◽  
Vol 109 (17) ◽  
pp. 5213-5216 ◽  
Author(s):  
Fumio Imashiro ◽  
Shiro Maeda ◽  
Kiyonori Takegoshi ◽  
Takehiko Terao ◽  
A. Saika
Keyword(s):  
Hydrogen Bond ◽  
Chemical Shifts ◽  
Intermolecular Hydrogen Bond ◽  
Nmr Chemical Shifts

Supplement To: OHO Hydrogen Bond Geometries and NMR Chemical Shifts: From Equilibrium Structures to Geometric H/D Isotope Effects, with Applications for Water, Protonated Water, and Compressed Ice

2009 ◽  
Vol 49 (2) ◽  
pp. s1-s36
Author(s):  
Hans-Heinrich Limbach ◽  
Peter M. Tolstoy ◽  
Natalia Pérez-Hernández ◽  
Jing Guo ◽  
Ilya G. Shenderovich ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Chemical Shifts ◽  
Isotope Effects ◽  
Nmr Chemical Shifts ◽  
Equilibrium Structures

scholarly journals Alternative probe for the determination of the hydrogen-bond acidity of ionic liquids and their aqueous solutions

2017 ◽  
Vol 19 (18) ◽  
pp. 11011-11016 ◽  
Author(s):  
Pedro P. Madeira ◽  
Helena Passos ◽  
Joana Gomes ◽  
João A. P. Coutinho ◽  
Mara G. Freire
Keyword(s):  
Hydrogen Bond ◽  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Chemical Shifts ◽  
Nmr Chemical Shifts ◽  
Hydrogen Bond Acidity ◽  
C Nmr

The alternative probe pyridine-N-oxide allows the determination of the hydrogen-bond acidity of both neat ionic liquids and their aqueous solutions based on 13C NMR chemical shifts.

scholarly journals Solvent-Dependent Structures of Natural Products Based on the Combined Use of DFT Calculations and 1H-NMR Chemical Shifts

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2290 ◽  
Author(s):  
Saima H. Mari ◽  
Panayiotis C. Varras ◽  
Atia-tul-Wahab ◽  
Iqbal M. Choudhary ◽  
Michael G. Siskos ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Natural Products ◽  
Chemical Shift ◽  
Intramolecular Hydrogen Bond ◽  
1H Nmr ◽  
Chemical Shifts ◽  
Oh Groups ◽  
X Ray ◽  
Nmr Chemical Shifts ◽  
Intramolecular Hydrogen

Detailed solvent and temperature effects on the experimental 1H-NMR chemical shifts of the natural products chrysophanol (1), emodin (2), and physcion (3) are reported for the investigation of hydrogen bonding, solvation and conformation effects in solution. Very small chemical shift of │Δδ│ < 0.3 ppm and temperature coefficients │Δδ/ΔΤ│ ≤ 2.1 ppb/K were observed in DMSO-d6, acetone-d6 and CDCl3 for the C(1)–OH and C(8)–OH groups which demonstrate that they are involved in a strong intramolecular hydrogen bond. On the contrary, large chemical shift differences of 5.23 ppm at 298 K and Δδ/ΔΤ values in the range of −5.3 to −19.1 ppb/K between DMSO-d6 and CDCl3 were observed for the C(3)–OH group which demonstrate that the solvation state of the hydroxyl proton is a key factor in determining the value of the chemical shift. DFT calculated 1H-NMR chemical shifts, using various functionals and basis sets, the conductor-like polarizable continuum model, and discrete solute-solvent hydrogen bond interactions, were found to be in very good agreement with the experimental 1H-NMR chemical shifts even with computationally less demanding level of theory. The 1H-NMR chemical shifts of the OH groups which participate in intramolecular hydrogen bond are dependent on the conformational state of substituents and, thus, can be used as molecular sensors in conformational analysis. When the X-ray structures of chrysophanol (1), emodin (2), and physcion (3) were used as input geometries, the DFT-calculated 1H-NMR chemical shifts were shown to strongly deviate from the experimental chemical shifts and no functional dependence could be obtained. Comparison of the most important intramolecular data of the DFT calculated and the X-ray structures demonstrate significant differences for distances involving hydrogen atoms, most notably the intramolecular hydrogen bond O–H and C–H bond lengths which deviate by 0.152 tο 0.132 Å and 0.133 to 0.100 Å, respectively, in the two structural methods. Further differences were observed in the conformation of –OH, –CH3, and –OCH3 substituents.

Hydrogen Bond Types, Binding Energies, and1H NMR Chemical Shifts

1999 ◽  
Vol 103 (40) ◽  
pp. 8121-8124 ◽  
Author(s):  
Janet E. Del Bene ◽  
S. Ajith Perera ◽  
Rodney J. Bartlett
Keyword(s):  
Hydrogen Bond ◽  
Chemical Shifts ◽  
Binding Energies ◽  
Nmr Chemical Shifts

Hydrogen bond length and proton NMR chemical shifts in proteins

1983 ◽  
Vol 105 (18) ◽  
pp. 5948-5949 ◽  
Author(s):  
Gerhard Wagner ◽  
Arthur Pardi ◽  
Kurt Wuethrich
Keyword(s):  
Hydrogen Bond ◽  
Bond Length ◽  
Chemical Shifts ◽  
Proton Nmr ◽  
Nmr Chemical Shifts ◽  
Hydrogen Bond Length

scholarly journals Experimental and Theoretical Evidence of Spin‐Orbit Heavy Atom on the Light Atom 1 H NMR Chemical Shifts Induced through H⋅⋅⋅I − Hydrogen Bond

2020 ◽  
Vol 26 (40) ◽  
pp. 8669-8669 ◽  
Author(s):  
Jan Vícha ◽  
Petr Švec ◽  
Zdeňka Růžičková ◽  
Maksim A. Samsonov ◽  
Kateřina Bártová ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Chemical Shifts ◽  
Heavy Atom ◽  
Spin Orbit ◽  
Light Atom ◽  
Nmr Chemical Shifts ◽  
H Nmr ◽  
Theoretical Evidence
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