  The magnetic and transport properties of the metal phthalocyanine (MPc) and
F$_{16}$MPc (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ag) families of
molecules in contact with S-Au wires are investigated by density functional
theory within the local density approximation, including local electronic
correlations on the central metal atom. The magnetic moments are found to be
considerably modified under fluorination. In addition, they do not depend
exclusively on the configuration of the outer electronic shell of the central
metal atom (as in isolated MPc and F$_{16}$MPc) but also on the interaction
with the leads. Good agreement between the calculated conductance and
experimental results is obtained. For M = Ag, a high spin filter efficiency and
conductance is observed, giving rise to a potentially high sensitivity for
chemical sensor applications.
