Cleverly designed molecular building blocks provide chemists with the
tools of a powerful molecular-scale construction set. They enable them
to engineer materials having a predictable order and useful solid-sta
te properties. Hence, it is in the realm of supramolecular chemistry t
o follow a strategy for synthesizing materials which combine a selecte
d set of properties, for instance from the areas of magnetism, photoph
ysics, and electronics. As a possible approach, host/guest solids whic
h are based on extended anionic, homo- and bimetallic oxalato-bridged
transition-metal compounds with two- and three-dimensional connectivit
ies are investigated. In particular, we report herein in detail about
their structural properties and their multifunctional characteristics
in the area of molecular magnetism and photophysics.