Page 83 - Visions of the Future Chemistry and Life Science

72 D. J. MACQUARRIE

homogeneous ones, leading to much less waste being produced. These
materials have been shown to be very active in a range of reactions, leading
to many important product types. One particularly important area of
chemistry is the selective preparation of one of a pair of mirror images of a
compound. This so-called chiral (from Greek; chiros – hand) catalysis
requires great control over the exact chemical environment of the catalytic
site, and is one of the major challenges in synthetic chemistry. Many drugs
and agrochemicals can exist as two forms which are mirror images of one
another, only one of which is useful, the other being useless or even dan-
gerous. It is therefore important to be able to prepare only the desired form.
As an example of mesoporous materials containing chiral metal-centred
catalysts, the group of Daniel Brunel in Montpellier has published work on
transformations using zinc species. Selectivity to the desired form was
good, approaching that achievable with conventional systems. Further
refinement of these systems will lead to improvements in the design of the
catalytic site, and its surrounds, and the prospects for this area of catalysis
are exciting.

4.4 Future prospects

The chemical industry produces an enormous range of products, from
petrol and other fuels, to additives which improve the performance of the
fuels, to plastics and fabrics (including the colours and fire retardants
which make them attractive and safe), colours, flavours and fragrances, and
further to the most complex molecules, which find use as agrochemicals
and pharmaceuticals. One of the strongest current trends in the industry
is towards green chemistry, which will involve redisign of many of these
processes for the preparation of this bewildering array of products. Much
success has already been achieved, and many major products are now pro-
duced using green technologies. Much remains to be done, however, and
several approaches are currently being investigated. One of the most excit-
ing is the development of new materials which can function as catalysts,
and whose structures can be fine tuned for the application in mind. The
rate of the advances made in the last eight years of the twentieth century
has been remarkable, and further advances will allow these fascinating
materials to contribute greatly to the quality of life for everyone in the
twenty-first century.
The future of these designer materials is very exciting indeed. Further