DEVELOPING AND DESIGNING NEW CHEMICALS AND MATERIALS - Chemistry: Notable Research and Discoveries - page 19

ray of different combinations of elements such as bismuth, strontium,
barium, yttrium, oxygen, and others. These compounds could then be
tested for special electronic properties.
Despite the contribution of methods such as combinatorial chemis-
try, developing new materials has remained a difficult endeavor. Com-
binatorial chemistry provides ample candidates to test but offers no
clues as to which candidate may be the best.
dESIgnIngTHErIgHTSTuFF
At the present stage of materials science, researchers either find a good
material by chance, in which case they hunt around for legitimate uses for
it, or they search for materials with specific properties and use techniques
such as combinatorial chemistry to generate a lot of testable compounds.
Most of the important materials used today have been found in this way.
The process certainly works, for modern technology enjoys an impres-
sive array of materials, including various metals, plastics, ceramics, and
no elaborate preparation is necessary. After the next step,
the products will be one of nine types: X-X-X, X-X-Y, X-X-Z,
X-Y-X, X-Y-Y, X-Y-Z, X-Z-X, X-Z-Y, and X-Z-Z. If the process is
repeated once more, 27 different compounds will appear.
Combinatorial chemistry generates a lot of compounds rap-
idly and efficiently.
The same technique can be used to modify a compound
that particularly interests researchers. Suppose this com-
pound almost but not quite fulfills an engineer's require-
ments. Perhaps after a slight modification, such as the
addition of a hydroxyl group (OH) at a certain point or the de-
letion of an acidic group elsewhere, the compound will work.
Researchers may set up conditions in which the compound
reacts with a number of chemicals, producing a vast array of
compounds that have the same basic structure but differ by
a chemical group or two. Somewhere in this collection may
be a winner.