From: Charles M. Hansen <charles.hansen@get2net.dk>
Date: Sun, Nov 14, 2010 at 2:31 PM
Subject: Hansen Hydrogen Bonding Parameter
To: arunan@ipc.iisc.ernet.in
Cc: Professor Steven Abbott <steven@stevenabbott.co.uk>,
jdurkee@precisioncleaning.com
 
 
Dear Prof. Arunan,
 
 
 
I have been forwarded a recent press release from those copied here
regarding a re-definition of hydrogen bonding. I would like to add my (our)
research to the data being considered.
 
 
 
A quantitative measurement of hydrogen bonding can be found by dividing the
total cohesion energy, measured quantitatively by evaporating a liquid, into
the three significant parts. Cohesion derived from:
 
 
 
Dispersion (London) atomic forces (typical of aliphatic hydrocarbons)
 
Permanent dipole permanent dipole forces (nitromethane, propylene carbonate)
 
Hydrogen bonding (water, glycols, alcohols, but also most other solvents to
one degree or another)
 
 
 
The sum of these effects is the total cohesion energy.
 
 
 
This division has now been done for about 10,000 chemicals, including gases,
liquids, solids, and polymers. The methodology is widely used in industry,
but the academic community has yet to recognize the value of the simplicity,
with two notable exceptions. These are Prof. Donald Patterson, Montreal, and
Prof. Costas Panayiotou, Univ. of Thessaloniki. More recently Prof. Steven
Abbott, supplemented by Dr. Hiroshi Yamamoto have been working on an
eBook/software called Hansen Solubility Parameters in Practice (HSPiP)
available from my website www.hansen-solubility.com. This is now being used
in many industries including pharmaceutical, chemical, electronic, plastics,
and so on. These parameters have been assigned to materials of such widely
different character as DNA, carbon dioxide, and of course water. The DNA
values show that it is not hydrogen bonding that binds the molecules, since
this is only about 14% of the energy involved. The dispersion and polar
effects make up the rest at about equal amounts. There are many predictions
that can be made and the methodology is holding up for drugs, skin
applications, and now even a flexographic printing in that allows zero
release to the atmosphere with superior print quality.
 
 
 
The type of experiment that convinced me about the essential correctness of
this division of energy was that one could very reliably predict given
mixtures of non-solvents that could dissolve a solute. These were often
mixtures with components having high and low hydrogen bonding parameters,
respectively. The same could also be done with mixtures where the components
had high and low polar parameters, respectively. I am not aware of any
experiments of this kind with the dispersion parameter since the higher
parameters necessary lead to solids.
 
 
 
Please excuse me for intruding on your work. IUPAC is a necessary
organization doing necessary things. I only hope that whatever definition of
hydrogen bonding develops is able to encompass the well-proven Hansen
hydrogen bonding parameter. This does indeed quantify the effect and should
provide clues as to its basis.
 
 
 
As a final comment, I am too modest to have introduced the Hansen
terminology as such. It was started by Dr. Alan Beerbower in 1970, and I
have necessarily followed his lead, also in the more scientific aspects.
 
 
 
As time goes on I keep thinking of a comment by the Danish comedian Victor
Borge to a question about how his life was changing as he grew older. The
response was “I plant larger trees”. I hope one of the trees I planted many
years ago is now large enough to have significance for the work you are
doing.
 
 
 
Charles M. Hansen