scholarly journals Variable-Temperature Study of Hydrogen-Bond Symmetry in Cyclohexene-1,2-dicarboxylate Monoanion in Chloroform-d

2014 ◽  
Vol 136 (11) ◽  
pp. 4355-4362 ◽  
Author(s):  
Charles L. Perrin ◽  
Kathryn D. Burke
Keyword(s):  
Hydrogen Bond ◽  
Variable Temperature ◽  
Temperature Study ◽  
Hydrogen Bond Symmetry

ATR or transmission—A variable temperature study comparing both techniques using [Fe(3ditz)3](BF4)2 as model system

2016 ◽  
Vol 86 ◽  
pp. 198-205 ◽  
Author(s):  
Danny Müller ◽  
Christian Knoll ◽  
Marco Seifried ◽  
Peter Weinberger
Keyword(s):  
Variable Temperature ◽  
Model System ◽  
Temperature Study

P.M.R. spectra of heteroaromatic molecules containing bridgehead nitrogen atoms. V. Pyrrolo[a]quinoline

1976 ◽  
Vol 29 (4) ◽  
pp. 847 ◽  
Author(s):  
ML Heffernan ◽  
GM Irvine
Keyword(s):  
Ambient Temperature ◽  
Spin System ◽  
Variable Temperature ◽  
Membered Ring ◽  
Coupling Constants ◽  
Ring Proton ◽  
Temperature Study ◽  
Proton Resonances ◽  
Cdcl3 Solution ◽  
Bridgehead Nitrogen

The p.m.r. spectra of (CD3)2SO and CDCl3 solutions of pyrrolo[a]quinoline, a nine-spin system, have been analysed. In the former case, the various multiplets were sufficiently non-overlapping for detailed double-irradiation experiments to be performed in order to confirm the proton assignments and to determine the magnitudes and relative signs of several inter-ring coupling constants. For the CDCl3 solution, it was found that there was broadening of the five-membered ring proton resonances at ambient temperature. A variable-temperature study showed that the broadening was arising from the exchange of the H1 and H3 protons and that the effects of exchange could be avoided by running the spectra at or below -20�.

Carbon-13 variable-temperature study of 1-hetero-spiro[2.5]octanes

1985 ◽  
Vol 23 (1) ◽  
pp. 2-6 ◽  
Author(s):  
P. Iratçabal ◽  
M. F. Grenier-Loustalot ◽  
A. Lichanot ◽  
F. Metras
Keyword(s):  
Variable Temperature ◽  
Temperature Study

Variable-temperature neutron diffraction studies of the short, strong N...O hydrogen bonds in the 1:2 co-crystal of benzene-1,2,4,5-tetracarboxylic acid and 4,4'-bipyridyl

2003 ◽  
Vol 59 (6) ◽  
pp. 794-801 ◽  
Author(s):  
John A. Cowan ◽  
Judith A. K. Howard ◽  
Garry J. McIntyre ◽  
Samuel M.-F. Lo ◽  
Ian D. Williams
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Variable Temperature ◽  
Intermediate Position ◽  
The Other ◽  
Tetracarboxylic Acid ◽  
Other Hand

The 1:2 adduct of benzene-1,2,4,5-tetracarboxylic acid and 4,4′-bipyridyl at 100 K has been studied by single-crystal neutron diffraction at 20, 200 and 296 K. The structure contains two short, strong N...O hydrogen bonds: one O—H...N hydrogen bond [O...N 2.6104 (17) Å at 20 K] and one short N—H...O hydrogen bond [N...O 2.5220 (17) Å at 20 K]. The N—H distance in the N—H...O hydrogen bond changes from 1.207 (3) Å at 20 K to 1.302 (4) Å at 296 K and the N...O distance increases to 2.5315 (16) Å at 296 K. At 200 K the H atom lies in an intermediate position 1.251 (6) Å from the N atom with an N...O separation of 2.520 (4) Å. The O—H...N hydrogen bond, on the other hand, does not change with temperature.

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