Redshift or adduct stabilization -- a computational study of hydrogen bonding in adducts of protonated carboxylic acids
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
It is generally expected that the hydrogen bond strength in a D-H-A adduct
is predicted by the difference between the proton affinities of D and A,
measured by the adduct stabilization, and demonstrated by the 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 delta-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.
is predicted by the difference between the proton affinities of D and A,
measured by the adduct stabilization, and demonstrated by the 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 delta-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.
Originalsprog | Engelsk |
---|---|
Tidsskrift | European Journal of Mass Spectrometry |
Vol/bind | 15 |
Udgave nummer | 2 |
Sider (fra-til) | 239–248 |
Antal sider | 10 |
ISSN | 1469-0667 |
Status | Udgivet - 2009 |
ID: 9593175