Langmuir-Blodgett (LB) films containing various oxalato complexes were
prepared using the so-called semiamphiphilic approach where inorganic
ions are adsorbed along a charged monolayer. In a first series of exp
eriments, lamellar materials based on monometallic oxalato complexes (
with Fe-III or Cr-III) have been characterized by X-ray diffraction, X
PS, FTIR, ESR, and SQUID measurements. The metal complexes are organiz
ed either in monolayers or in bilayers within the LB films, depending
on the charge density of the organic layer. Within each inorganic laye
r, the complexes present a particular orientation or distortion. Final
ly, the magnetic behavior of such LB films is simply described by the
Curie law. In a second series of experiments, synthesized heterobimeta
llic complexes based on a M-1(III)-M-2(II)-M-1(III) trimer have been o
rganized thanks to the LB technique. Magnetization measurements made o
n these multilayers show a deviation from the Curie law and from that
observed in the powder. They emphasize the interest to control perfect
ly the molecular organization in order to build up specific extended m
agnetic systems.