Acid salts of carboxylic acids, crystals with some ‘very short” hydrogen bonds

2008 ◽  
pp. 141-199 ◽  
Author(s):  
J. Clare Speakman
Keyword(s):  
Hydrogen Bonds ◽  
Carboxylic Acids ◽  
Short Hydrogen Bonds ◽  
Acid Salts

Comparison of low-barrier hydrogen bonds in acid salts of carboxylic acids and basic salts of betaines – FTIR study

1999 ◽  
Vol 484 (1-3) ◽  
pp. 117-124 ◽  
Author(s):  
Piotr Barczyński ◽  
Iwona Kowalczyk ◽  
Monika Grundwald-Wyspiańska ◽  
Mirosław Szafran
Keyword(s):  
Hydrogen Bonds ◽  
Carboxylic Acids ◽  
Ftir Study ◽  
Low Barrier Hydrogen Bonds ◽  
Acid Salts

Solid-state13C and1H NMR study of anomalous acid salts of dibasic carboxylic acids

1992 ◽  
Vol 30 (5) ◽  
pp. 440-448 ◽  
Author(s):  
Lawrence H. Merwin ◽  
Sidney D. Ross
Keyword(s):  
Carboxylic Acids ◽  
Nmr Study ◽  
Acid Salts

scholarly journals S−H…O and O−H…O Hydrogen Bonds‐Comparison of Dimers of Thiocarboxylic and Carboxylic Acids

ChemPhysChem ◽  
2020 ◽  
Vol 21 (15) ◽  
pp. 1620-1620
Author(s):  
Mohammad Aarabi ◽  
Samira Gholami ◽  
Sławomir J. Grabowski
Keyword(s):  
Hydrogen Bonds ◽  
Carboxylic Acids

Redshift or Adduct Stabilization—A Computational Study of Hydrogen Bonding in Adducts of Protonated Carboxylic Acids

2009 ◽  
Vol 15 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Solveig Gaarn Olesen ◽  
Steen Hammerum
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Bond Strength ◽  
Bond Length ◽  
Carboxylic Acids ◽  
Computational Study ◽  
Proton Affinities ◽  
Oh Groups ◽  
Hydrogen Bond Strength ◽  
Length Changes

It is generally expected that the hydrogen bond strength in a D–H•••A adduct is predicted by the difference between the proton affinities (Δ PA) of D and A, measured by the adduct stabilization, and demonstrated by the infrared (IR) redshift of the D–H bond stretching vibrational frequency. These criteria do not always yield consistent predictions, as illustrated by the hydrogen bonds formed by the E and Z OH groups of protonated carboxylic acids. The Δ PA and the stabilization of a series of hydrogen bonded adducts indicate that the E OH group forms the stronger hydrogen bonds, whereas the bond length changes and the redshift favor the Z OH group, matching the results of NBO and AIM calculations. This reflects that the thermochemistry of adduct formation is not a good measure of the hydrogen bond strength in charged adducts, and that the ionic interactions in the E and Z adducts of protonated carboxylic acids are different. The OH bond length and IR redshift afford the better measure of hydrogen bond strength.

Structure of ammonium hydrogen succinate above and below the phase transition around 170K

1996 ◽  
Vol 52 (2) ◽  
pp. 323-327 ◽  
Author(s):  
A. Hirano ◽  
Y. Kubozono ◽  
H. Maeda ◽  
H. Ishida ◽  
S. Kashino
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Hydrogen Bonds ◽  
Order Phase Transition ◽  
Space Group ◽  
X Ray ◽  
Ammonium Hydrogen ◽  
Significant Change ◽  
Short Hydrogen Bonds ◽  
Second Order Phase Transition

For crystals of ammonium hydrogen succinate it is known that the space group is P{\bar 1} with Z = 2 at 293 K and the second-order phase transition occurs around 170 K. X-ray crystal structure analyses above and below 170 K have been carried out in order to study the change in mode of short hydrogen bonds between the hydrogen succinate ions. The space group was determined to be P{\bar 1} at 150 and 190 K by structure analysis. No ordering of the H-atom positions in the short hydrogen bonds occurs by the phase transition. The hydrogen bonds show a decrease in the O...O distances with a decrease in temperature from 290 to 190 K, but no significant change in the geometries between 190 and 150 K. Disorder of the NH4 + ion is not observed at 297, 190 and 150 K. Significant change through the phase transition is found only in the geometry of one of the N—H...O hydrogen bonds between ammonium and hydrogen succinate ions.

scholarly journals Short hydrogen bonds in the catalytic mechanism of serine proteases

2008 ◽  
Vol 73 (4) ◽  
pp. 393-403 ◽  
Author(s):  
Vladimir Leskovac ◽  
Svetlana Trivic ◽  
Draginja Pericin ◽  
Mira Popovic ◽  
Julijan Kandrac
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Active Site ◽  
Serine Proteases ◽  
Active Sites ◽  
Catalytic Mechanism ◽  
Data Bank ◽  
Ground State Structure ◽  
Low Barrier Hydrogen Bonds ◽  
Short Hydrogen Bonds

The survey of crystallographic data from the Protein Data Bank for 37 structures of trypsin and other serine proteases at a resolution of 0.78-1.28 ? revealed the presence of hydrogen bonds in the active site of the enzymes, which are formed between the catalytic histidine and aspartate residues and are on average 2.7 ? long. This is the typical bond length for normal hydrogen bonds. The geometric properties of the hydrogen bonds in the active site indicate that the H atom is not centered between the heteroatoms of the catalytic histidine and aspartate residues in the active site. Taken together, these findings exclude the possibility that short "low-barrier" hydrogen bonds are formed in the ground state structure of the active sites examined in this work. Some time ago, it was suggested by Cleland that the "low-barrier hydrogen bond" hypothesis is operative in the catalytic mechanism of serine proteases, and requires the presence of short hydrogen bonds around 2.4 ? long in the active site, with the H atom centered between the catalytic heteroatoms. The conclusions drawn from this work do not exclude the validity of the "low-barrier hydrogen bond" hypothesis at all, but they merely do not support it in this particular case, with this particular class of enzymes.

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