Subject: Re: pi-stacking interactions

From: <[email-masked]>
Date: Thu, 7 May 1998 12:07:34 +0200 (DFT)

Dear CCLers,

Many theoretical studies on pi-stacking interactions have been achieved.

Ab initio calculations yield satisfactory results if high level theoretical levels are used. See:

P. Hobza, H. L. Selzle, E. W. Schlag, Chem. Rev. 1994, 94, 1767 and
references therein.

C. Chipot, R. Jaffe, B. Maigret, D. A. Pearlman, P. A. Kollman, J. Am. Chem.
Soc. 1996, 118, 11217.

An AM1 study on arene-arene complexes has been published:

V. E. Williams, R. P. Lemieux, G. R. J. Thatcher, J. Org. Chem. 1996, 61,
1927.

According to the authors, the results "showed good agreement with
literature data on related experimental systems". In my opinion, the
agreement is purely qualitative. I think that semiempirical methods are not
adequate for pi-stacking studies due to their poor performance of
medium-range interactions:

V. Buss, J. Messinger, N. Heuser, QCPE Bull. 1991, 11, 5.
G. I. Csonka, J. Comp. Chem. 1993, 14, 895.
G. I. Csonka, J. G. Angyan, J. Mol. Struct. (THEOCHEM) 1997, 393, 31.

Finally, MM3 method has been specifically parametrised in order to consider
pi interactions:

N. L. Allinger, Z.-q. Zhu, K. Chen, J. Am. Chem. Soc. 1992, 114, 6120.

However, I think that there are not specific studies on the performance of the
MM3 method on pi-stacking interactions.

Luis Salvatella
Departement de Chimie Theorique
Universite de Nancy I
France

>From [email-masked] Thu May  7 04:24 EDT 1998
From: <[email-masked]>
Subject: Re: CCL:pi stacking interactions
To: [email-masked] (Ohyun Kwon)
Date: Thu, 7 May 1998 10:07:43 +0200 (DFT)

There have been a number of theoretical investigations  on pi-stacking,
at various levels of approximation.  You can look at the work of Hobza,
Selzle and Schlag, J. Chem. Phys. 1990, 93, 5893;  J. Phys. Chem. 1993,
97, 3937; J. Am. Chem. Soc. 1994, 116, 3500; Chem. Rev. 1994, 94, 1767.
Those essentially  cover ab initio studies of the benzene dimer.  Worth
looking at is the paper of  Karlstrom et al.,  J. Am. Chem. Soc.  1983,
105, 3777. More recently,  the work of Jaffe and Smith,  J. Chem. Phys.
1996, 105, 2780, and J. Phys. Chem., 100, 9624  presents  benchmark  QM
calculations for that system.

On the statistical simulation side, the work of Linse, J. Am. Chem. Soc
1990, 114, 1744; 1992, 114, 4366; 1993, 115, 8793  is an important one.
Equally interesting  is the paper  of  Jorgensen and Severance,  J. Am.
Chem. Soc. 1990, 112, 4768,  on the orientational averaged potential of 
mean force of the benzene dimer.  Very recently, we reinvestigated this
problem at the QM and MM levels of approximation. Chipot et al., J. Am.
Chem. Soc. 1996, 118, 11217.

Best wishes,

Chris
_______________________________________________________________________

Chris Chipot, Ph.D.                  
Laboratoire de Chimie Theorique          Phone:      (33) 3-83-91-25-96
U.M.R. C.N.R.S. No 7565                  Fax:        (33) 3-83-91-25-30
Universite Henri Poincare - Nancy I       
B.P. 239
54506 Vandoeuvre-les-Nancy Cedex         E-mail: [email-masked]

`The light shines through the darkness
 and the darkness has not overcome it'
_______________________________________________________________________