From rgab /at\mx.trpntech.com Thu Sep 19 12:28:02 1996 Received: from mx.trpntech.com for rgab ":at:" mx.trpntech.com by www.ccl.net (8.7.5/950822.1) id MAA02249; Thu, 19 Sep 1996 12:20:07 -0400 (EDT) Message-ID: Date: 19 Sep 1996 09:17:30 -0700 From: "Richard Bone" Subject: Floppy Molecules To: "CCL" X-Mailer: Mail*Link SMTP-QM 3.0.2 Subject: Floppy Molecules Apologies for coming into this late in the day. There is a fairly large literature on "floppy" or "non-rigid" molecules. I think that the already-mentioned reference to Bunker's book "Molecular Symmetry and Spectroscopy" covers the most important work in the field. But there is much else. 2 references I have to hand are: H. Frei, A. Bauder, H. H. Gunthard, "The Isometric Group of Nonrigid Molecules", in Top. Curr. Chem., Vol. 81, Large Amplitude Motion in Molecules, I, p3, (1979) "Symmetries and Properties of Non-Rigid Molecules", Ed. J. Maruani and J. Serre, Studies in Physical and Theoretical Chemistry, 23, Elsevier, Amsterdam, (1982). There is also a recently published book-volume edited by Yves Smeyers "Structure and Dynamics of Non-Rigid Molecular Systems", Kluwer, 1994, in which I have an article with some perspectives on how to treat the problem of inter- conversions between minima of different geometries/symm- etries. One small point on the use of the term "fluxional": I have also seen it used to refer to inorganic molecules where no valence tautomerisation occurs, the archetypal example of which is PF_5. The Smith-Berry internal rotation which interconverts all the indistinguishable Trig-bipy isomers doesn't change any bonding very much. Richard Bone __________________________________________________________ Richard G. A. Bone, PhD. Terrapin Technologies, Inc. 750-H Gateway Blvd. South San Francisco CA 94080-7020 USA Tel. +1 (415) 244 9303 FAX +1 (415) 244 0705 E-mail rgab |-at-| trpntech.com http://www.sosei.com/Companies/Terrapin.html