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Date: Wed, 9 Feb 2000 10:53:04 -0600
To: <chemistry@ccl.net>
From: "Robert E. Harris" <HarrisR@missouri.edu>
Subject: Re: Pseudorotation References So Far

I asked for information on pseudorotation in ring molecules, the motion
that moves the out-of-plane displacements around the ring without rotating
the ring.  I got some helpful references from those who responded to my
post.  Alas, I've lost their posts, so I can't thank them all.  (I'm
interested in the thermodynamics of large sulfur rings.  My remarks are of
course influences by my interest.)

What I have found most helpful has been Herbert L. Strauss, Ann. Rev. Phys.
Chem. 1983, 34:301-28.  Pseudorotation: A Large Amplitude Molecular Motion.
(I thank H. Strauss for his help, but he did not point this one out to me!)
This is very useful and has lots of references.  It is mostly concerned
with the motion I am interested in, but it does have some discussion of the
"pseudorotation" of the PF5 type.

Kilpatrick, J. E.; Pitzer, K. S.; Spitzer, R.  J. Am. Chem. Soc. 69,
2483-88 (1947).  The grand-daddy pseudorotation motion paper, devoted to
cyclopentane (thermodynamic orientation).   See  also 80,697 (1958) for
correction of the symetry number of cyclopentane.

Cremer, D.; Pople, J. A.  J. Am. Chem Soc. 97, 1354-8 (1975).  They give a
generalized coordinate system for describing ring puckering, but not
directly applied to pseudorotation as a motion..  The coordinate system is
useful for defining the pseudorotation angle, so it is a useful paper for
the discussion of the motion.  One should also look at earlier papers by H.
M. Pickett and H. L. Strauss, J. Am. Chem. Soc. 92, 7281-90 (11970) and J.
Chem. Phys.55, 324-34 (1971).

Several articles in Conformational Behavior of Six-Membered Rings (E.
Juaristi, ed., VCH, 1995) also merit attention for discussions of motions
in six member rings, particularly "100+ Years of Conformational Analysis"
by E. L. Eliel (pp. 1-24) and  "Ab Initio Studies of Six-Membered Rings:
Present Status and Future Developments" by D.Cremer and K. J. Szabo (pp.
59-136).  There are a lot of references, as well as many nice illustrations
in these articles.  The other articles in this volume are interesting,
also.

Robert E. Harris  Phone: 573-882-3274  Fax:  573-882-2754
Department of Chemistry, University of Missouri-Columbia
Columbia, Missouri, USA 65211