New mononuclear [Mn(HL)3].2CHCl3 (H2L = 2-salicyloylhydrazono-1,3-dithiolane) and binuclear Mn2(mu-OCH3)2(HL)4 manganese (III) complexes have been synthesized and structurally characterized. The binuclear complex, described in this communication, displays very strong intramolecular ferromagnetic coupling (J = + 19.7 cm-1), which is confirmed by DFT calculations. The negative sign of the axial magnetic anisotropy parameter, which is crucial for a possible single molecule magnet behavior and for any future use of this complex in more complex extended architectures, is also unambiguously determined by careful fit of magnetization curves and by DFT calculations.

Discrete and extended architectures based on the association of lanthanide ions with two derivatives of cinnamic acid (2-methoxycinnamic acid and 3-methoxycinnamic acid) have been synthesized and characterized by IR spectroscopy, elemental analyses, X-ray diffraction and magnetic measurements. The use of the 2-methoxycinnamic ligand enables the synthesis of a series of dinuclear complexes (Ce (1), Nd (2), Gd (3), Dy (4)), while the presence of 3-methoxycinnamic acid induces the formation of one-dimensional coordination polymers (Ce (5), Nd (6), Dy (7)). Investigations of the magnetic properties of the complexes reveal that they all exhibit field-induced slow relaxation of the magnetisation, mainly induced by Raman and direct relaxation processes.

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