Subject: NBO

From: Nurcan Senyurt <[email-masked]>
Date: Tue, 13 Aug 2002 14:08:16 +0300 (EET DST)

Dear CCL users
I have two different conformers of a molecule. I guess that in one of
them, there are hyperconjugative interactions that stabilize it
with respect to the other. I have performed NBO analysis and checked the
donor-acceptor interactions.
 My question is: Is it logical to sum all the donor-acceptor interactions
and deduce that the one with the higher sum is stabilized more than the
other by the hyperconjugative interactions. Or should I choose specific
donor-acceptor interactions among the tabulated in NBO analysis? My worry
is; in the first case antibond-antibond interactions are also
considered and in the latter case it is hard to make a wise selection
among the donor-acceptor interactions.
 I appreciate any comments to my question. Thank you in advance.

 Nurcan Tuzun
 Bogazici University
 Chem Department
 80815 Bebek, Istanbul
 Turkey