Subject: Nomenclature question

From: "Hr. Dr. S. Shapiro" <[email-masked]>
Date: Mon, 02 Jun 1997 08:28:47 +0200

Dear Colleagues;

        I have a question about the proper terminology to describe
flexibility in molecules.

        As a case in point, consider the molecule
2-mercapto-3-isopropyl-5-methylnaphthalene.  Such a molecule has five bonds
where rotation can take place: C(2)-S, C(3)-CH(CH3)2, C(5)-CH3, and the two
CH-CH3 bonds of the isopropyl moiety.  Now, it seems to me that only two of
these five possible rotations will have any significant conformational
consequences, viz. C(2)-S and C(3)-CH(CH3)2.  Under these circumstances,
would it be correct to say that 2-mercapto-3-ispropyl-5-methylnaphthalene
has "two principal degrees of conformational freedom"?  If not, what short
phrase would you suggest to indicate that only 2/5 possible rotations in
this molecule will have any significant conformational consequences?

        Thanks in advance to all responders.

Sincerely,

S. Shapiro
[email-masked]