With platinum and rhodium, palladium is one of the most important
members of the platinum metal group. The last Gmelin treatment of it was
in 1942, and knowledge of its properties and chemistry has made enormous
strides since then. This volume is primarily concerned with binary
compounds and with the coordination complexes derived from them.
Although it is a member of the nickel-palladium-platinum triad, it more
closely resernblas platinum in its binary and coordination chemistry,
though being a second-row transition element it displays less tendency
than does platinum to assume higher oxidation states. ln heterogeneous
and homogeneous catalysis, referred to at appropriate points, palladium
and its complexes are of great importance in bulk and fine chemieals
production, effecting a wide variety of organic transformations. The
arrangement of material in this volume follows the traditional Gmelin
arrangement. Within each category of compounds or complexes the material
is arranged, as usual, in order of ascending metal oxidation states (e.
g., palladium(ll) precedes palladium(IV)). The chemistry of the
palladium-hydrogen system is so large that it merits a separate volume,
so this book starts with the binary oxides and oxopalladates followed by
hydroxides, hydroxo complexes and aquo complexes. Then nitrides and
nitrates are treated. They are followed by the large chapters on halides
and their complexes (172 pages). The largest single chapter in this
volume (11 0 pages) deals with chlorides, chloropalladates and other
chloro complexes.