Combined oxygen, in the form of water, metal oxides, silicates and other
oxyions, accounts for about 50% by weight of the earth's crust. The
chemistry of this most abundant element has two major aspects: that of
water and aqueous solutions of electrolytes, and that of the solid
state. The methodology and techniques appropriate for the study of these
fields are sufficiently different that there have been very few points
of contact between solution- and solid state chemists. One such contact,
of great potential value, is provided by the extensive class of
polyoxoanions formed by the transition metals of groups 5 and 6. As
'heteropoly and isopoly acids' these polyanions have been known and
investigated for more than a century. The pre- sent book is an attempt
to survey the chemistry, structures, and applications of these species.
Although the book forms part of a series in inorganic chemistry, the
field of polyoxometalates deserves wider attention, for example, from
organic chemists, especially those concerned with homogeneous and
heterogeneous catalysis, and from biochemists, solid state- and
materials scientists.