The supreme advantages of electron microscopy (EM) in the chemical
sciences are briefly recalled: By judicious use of electron
optical techniques, vital information of a structural, mechanistic,
compositional, and often of an electronic kind may be retrieved.
Not only are insights gained (through EM) into the existence
of whole new families of structures hitherto unperceived, but
one also uncovers the structural characteristics of imperfections
in solids. And it is often the case that these imperfections
reflect or suggest altogether new structures, hitherto unconceived.
EM is, therefore, a powerful agent for aiding chemical synthesis
of new materials. This is particularly important in the field
of heterogeneous catalysis, since altogether new types of catalytic
materials may be, on the one hand, defined, described, identified,
and characterised, and, on the other, designed and synthesised.
There is also the ever-improving role of the electron microscope
as an analytical tool: Very few other techniques within reach
of the chemist can rival it in its sensitivity and detection
limits. (Scanning instruments now permit the imaging and the
identification of nanoclusters consisting of just a few atoms.)
But there are numerous other branches of chemistry besides
catalysis and surface science where EM proves invaluable, as
we outline herein, in elucidating structure–property or
composition and structure interrelationships.