  In the last years there has been a great interest in magnetic systems formed
by a cluster of transition metal ions covalently bonded via superexchange
bridges, embedded in a large organic molecule. Following the synthesis and the
structural and magnetic characterization of these magnetic molecules by
chemists, the physicists realized the great interest of these systems as a
practical realization of zero-dimensional model magnetic systems. In fact the
magnetic molecules can be synthesized in crystalline form whereby each molecule
is magnetically independent since the intramolecular exchange interaction among
the transition metal ions is dominant over the weak intermolecular, usually
dipolar, magnetic interaction. We have undertaken a systematic NMR
investigation of molecular nanomagnets since back in 1996. The present review
tries to give an account of the main results obtained so far and of the many
exciting projects that still lie ahead. The work was done through a continuous
very fruitful collaboration among three NMR laboratories: at the University of
Pavia, Italy, at Iowa State University and Ames Laboratory, Ames, IA, USA and
at Hokkaido University, Sapporo, Japan with occasional very useful
collaborations with the high field NMR lab. in Grenoble, France. None of the
work could be done without the precious collaboration and help of our
colleagues in chemistry at the University of Florence and of Modena, Italy and
at Ames Laboratory in USA who synthesized and characterized the samples used in
the NMR work.
