Date: Fri, 13 Oct 2006 01:38:16 -0400
From: jdannenberg@gc.cuny.edu
To: E. Arunan <arunan@ipc.iisc.ernet.in>
Subject: Re: IUPAC
Parts/Attachments:
1 OK ~80 lines Text
2 Shown ~88 lines Text
----------------------------------------

Dear Arunan,

I apologize for not responding ssoner. I became involved in some other
things that have distracted me a bit.

As for the definition:
The hydrogen bond is an attractive interaction between a group X^ÖH and
an atom or a group of atoms Y, in the same or different molecule(s), when
there is evidence of bond formation.
I think this is fine.

I have some reservations about the long list of criteria for evidence for
bond formation. I feel that these tend to muddy an otherwise clear
definition.  We have now ventured from defining the hydrogen-bond to
listing acceptable criteria for evidence of H-bond  formation.  I think
this does not help as exceptions can be found to most of the criteria,
some of the criteria are either ambiguous or open to overly broad
interpretation, and the disclaimer at the beginning makes the situation
more nebulous.

My own feeling is to keep it simple. The definition above is simple. The
evidence for bonding should be whatever is deemed acceptable. I should
imagine that there will be differences of opinion on what is acceptable,
but that is OK. I imagine that new experimental methods might lead to new
kinds of evidence for bonding in the future. We must leave room for
these. What I would not like to see is overly lawyerly interpretations
based upon the listed criteria.

I might add that we have taken what I consider to be an overly long time
to complete this task.

Best Regards,

Joe