Synthesis and magnetochemistry of heterometallic triangular Fe2III LnIII (Ln = La, Gd, Tb, Dy, and Ho) and Fe2IIIYIII complexes

A series of Fe(2)Ln (Ln = La, Gd, Tb, Dy and Ho) and Fe2Y complexes have been synthesized via metal substitution and characterized by single crystal X-ray diffraction. All the molecules are isostructural and have a Fe(2)LnO triangular core with the oxygen atom existing as an mu(3)-oxo(2-) anion. DC and AC magnetic susceptibility studies were performed on all the molecules. For Fe(2)Ln (Ln = Gd, La) and Fe2Y, the data were fitted to Van Vleck equations and the magnetic coupling constants were obtained. In all cases, the two Fe(III) spins were found to be antiparallel to each other in the ground state leaving the heterometal to remain essentially uncoupled.