From: David Pratt <pratt@pitt.edu>
Date: Thu, Dec 2, 2010 at 9:34 PM
Subject: Hydrogen bond
To: arunan@ipc.iisc.ernet.in
Cc: Vanesa Vaquero <VAV15@pitt.edu>
 
Prof. Arunan,
 
Stimulated by your efforts to provide new definitions of the hydrogen bond,
my postdoc Dr. Vanesa Vaquero and I would like to propose the inclusion of
an additional criterion that relates to the changes in quadrupole coupling
that are observed when hydrogen bonds are formed with suitable nuclei, such
as N-14. The following is a proposed entry:
 
 
 
"In cases where X or Y is N-14 or some other atomic nucleus with I > 1/2,
the formation of an X-H...Y-Z hydrogen bond leads to significant changes
 
in the nuclear quadrupole coupling constants of these atoms, due to the
distortion of its electronic environment."
 
 
 
Representative data illustrating this behavior are presented in the attached
table.
 
 
 
Thank you, and best wishes,
 
 
 
David Pratt
 
University of Pittsburgh.