New photomagnetic cyanido-bridged Cu(II)-Mo(IV) oligonuclear complexes: slight modification of the blocking ligands induces different structures.

A pentanuclear complex, [Mo(CN)8{CuL1}2{CuL1(H2O)}2].6H2O 1, and a decanuclear one, [Mo(CN)8{CuL2}3{CuL2(H2O)}]2.10H2O 2, have been obtained following the building-block approach (HL1 and HL2 are tridentate Schiff bases obtained by reacting salicylaldehyde with 2-aminomethyl-pyridine and 2-aminoethyl-pyridine, respectively). Both compounds present reversible photo-induced magnetic properties interpreted as a MoIV-CuII charge transfer. Compound 2 exhibits a lower efficiency of this metal-metal charge transfer than compound 1 attributed to a less flexible structure of 2 compared to 1.