Re: CCL:descriptors for the 'shape' and 'size' of molecules

 Norman, you wrote:
 > I am looking for a simple (!?) method to describe the 'size' and
 > topology of a molecule.
 > The aim is to establish a correlation between experimentally observed
 > retention times (by liquid cromatography) and the 'shape' of several
 > pure hydrocarbons
 > (bigger species including 'disk' and umbrella-shaped molecules).
 > I have no experience in this field of research, whatsoever, so any hints
 > or comments
 > would be appreciated.
 I think you will find that quite a lot has already been done by
 others in modelling retention times (of all sorts) often using
 hydrophobicity descriptors of one form or another (retention times
 are frequently used as hydrophobicity descriptors themselves).  I
 guess you need to do a search.
 As for shape descriptors (and others) I suggest you have a look at
 some QSAR reviews and/or books.  I wrote one in 1991:
 D.J. Livingstone, "Quantitative Structure-Activity Relationships" in:
 Similarity Models in Organic Chemistry, Biochemistry and Related
 Fields (Eds, R.I. Zalewski, T.M. Krygowski & J. Shorter), Elsevier,
 1991, pp 557-627).
 You could also try:
 The  book by Hansch & Leo (Exploring QSAR Fundamentals and
 Applications in Chemistry and Biology, ACS, 1995, ISBN
 0-8412-2987-2).  Chapter 3 (Parameters) of Hugo Kubinyi's book (QSAR: Hansch
 and related Approaches, VCH, Weinheim, 1993, ISBN 3-527-30035-X) and
 it might pay to take a look at "Partition Coefficient Determination and
 Estimation", (Eds W. Dunn, J.
 Block & R. Pearlman), Pergamon, 1986, ISBN ???? - although this is
 perhaps a little dated now.
 Hope this helps,
 D.J. Livingstone
                        Cheyney House, 19-21 Cheyney St.,
                        Steeple Morden. Herts UK SG8 0LP
 Phone & Fax: +44 (0)1763 852569
 e-mail davel[ AT ]