From toukie "-at-" zui.unizh.ch  Thu Nov  3 06:23:24 1994
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Date: Thu, 3 Nov 1994 11:27:30 +0100 (MET)
From: "Hr Dr. S. Shapiro" <toukie(+ at +)zui.unizh.ch>
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To: chemistry*- at -*ccl.net
Subject: Rate of rotation of methyl groups


Dear Colleagues:


     I am seeking information on the rate of rotation of methyl groups:

     (i) firstly, I am seeking information/references describing the rate of
rotation of the terminal methyl groups of n-alkanes at ca. room temperature
(either experimental or theoretical).

    (ii) secondly, I am seeking information/references describing the rate of
rotation of the C-19 methyl groups of steroids (or the rate of rotation of
methyl groups attached to structurally related, hindered quaternary carbon
atoms) at ca. room temperature (either experimental or theoretical).

   (iii) finally, I am seeking information/references on the RELATIVE rates
of rotation of perhydro and isotopically substituted methyl groups.  For
example, what would one expect to be the rate of rotation of a chiral methyl
group (CHDT) RELATIVE to a nonchiral perhydro methyl group (CH3) in the same
molecule at the same temperature?

     I thank all responders for generously sharing their information/calcula-
tions with me.


Yours respectfully,

(Dr.) S. Shapiro
Institut fuer orale Mikrobiologie und allgemeine Immunologie
Zentrum fuer Zahn-, Mund-, und Kieferheilkunde der Universitaet Zuerich
Plattenstrasse 11
Postfach
CH-8028 Zuerich, Switzerland

Internet: toukie-!at!-zui.unizh.ch
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