From davel@chmqst.demon.co.uk Thu Apr 2 13:21:52 1998 Received: from post.mail.demon.net for davel@chmqst.demon.co.uk by www.ccl.net (8.8.3/950822.1) id MAA04009; Thu, 2 Apr 1998 12:37:01 -0500 (EST) Received: from chmqst.demon.co.uk ([158.152.83.101]) by post.mail.demon.net id aa1017044; 2 Apr 98 17:34 GMT From: David Livingstone Organization: ChemQuest To: Norman Goldberg Date: Thu, 2 Apr 1998 11:12:59 +0100 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: Re: CCL:descriptors for the 'shape' and 'size' of molecules Reply-to: davel@chmqst.demon.co.uk CC: CHEMISTRY@www.ccl.net Priority: normal In-reply-to: <3521FC2C.2754649C@tu-bs.de> X-mailer: Pegasus Mail for Win32 (v2.54) Message-ID: <891538485.1017044.0@chmqst.demon.co.uk> 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 Analysis 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, Dave. ------------------------------------------------------------------ D.J. Livingstone ChemQuest Cheyney House, 19-21 Cheyney St., Steeple Morden. Herts UK SG8 0LP Phone & Fax: +44 (0)1763 852569 e-mail davel@chmqst.demon.co.uk ------------------------------------------------------------------