Re: Is H-bonding really there?

From: Ioana Cozmuta <ioana_at_nas.nasa.gov>
Date: Tue 1 Oct 2002 14:44:55 -0700 (PDT)

Hi amber-users,

It just happened that I found a book in the library called "An
introduction to hydrogen bonding" by George A Jeffrey. I know that there
are lost of books and papers written on hydrogen bonding so I am not
saying that this book is the best. However what I liked about is that it
covers the basics in a very non-demanding way with simple explanations and
examples.
Related to the discussion few days ago, there are three chapters that I
think would be of help. "Geometry in crystals" covers some structural
definitions and the way hydrogen bonding contributes to the packing of
molecules in the solid state. "The vibrational properties" talks about the
thermal motion of the molecules at very low temperatures and the
difference in this motion between hydrogen atoms and heavier atoms. There
are also some nice figures of the potential energy surfaces corresponding
to the motion of hydrogen atoms in a hydrogen bond (in principle the
presence of a hydrogen bond will broaden the potential energy curve and
also reduces the barrier). This sub-chapter also has a short paragraph
stating what one would expect intuitively as well, that hydrogen bonds are
weakened when temperature is increased by increasing the vibrational
motion of the involved atoms (thus increasing the average HB angles).
However this effect is not that much pronounced in solids.
Last but not least, there is a whole chapter dedicated to "Water, water
dimers, ices, hydrates" which I think is most relevant for the ongoing
discussion.
I want to make sure that my message is not misunderstood: I am not
advertising for the above book, it just happened that I found it and I
thought it's interesting to share it with those of you who want to know
more on the subject.

Thanks,
Ioana
Received on Tue Oct 01 2002 - 14:44:55 PDT
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