This book Organic Photochromic and Thermochromic Compounds is the fourth major treatise on
photochromism involving organic molecules and derived systems. The first such book was edited
by G.H. Brown in the Weissberger series in 1971 the second was edited by H. Dürr and H.
Bouas-Laurent in the Elsevier series in 1990. A third book edited by C.B. McArdle should be
added to the list which focuses on the very important topic of the behavior of photochromic
systems in polymer matrices. The current book is a result of the large increase in the number
of publications and patents concerning photochromic compounds and their use in various
applications (e.g. ophthalmic lenses security printing etc.) during the last 10 years. As a
result of this increased interest two successful International Symposia on Photochromism have
been held: the first ISOP93 in France on Embiez Island near Bandol (September 12-16 1993)
and the second ISOP96 in the United States in Clearwater Florida (September 8-12 1996). The
number of countries represented at each of these symposia (17 and 16 respectively) attests to
the international scope of the photochromic research community. This global interest is also
exemplified by the authors of the chapters within this book. The second volume of this new
review is focused on the physico-chemical properties and photochromic behavior of the
best-known systems which have led to new developments in the known photochromic series or the
discovery of new families. Chapters are included on the most appropriate physico-chemical
methods by which photochromic substances can be studied (spectrokinetic studies on
photostationary states Raman spectroscopy EPR chemical computations and molecular modeling
X-ray diffraction analysis). In addition special topics such as interaction between
photochromic compounds and polymer matrices photodegradation mechanisms and potential
biological applications have been treated. The last chapter on thermochromic materials is
included to emphasize the chemical similarities between photochromic and thermochromic
materials. In general the literature cited within the chapters covers publications through
1995.
