Reversible Single-Crystal-to-Single-Crystal Transformation in Photomagnetic Cyanido-Bridged Cd4M2 Octahedral Molecules.

Two new hexanuclear octahedral cyanido-bridged clusters, {[CdII(bpy)2]4[WIV(CN)8]2}·10H2O (Cd4W2) and {[CdII(bpy)2]4[MoIV(CN)8]2}·10H2O (Cd4Mo2), have been obtained and characterized structurally and photomagnetically. Both compounds show a very rare and reversible single-crystal-to-single-crystal transformation upon dehydration accompanied by marked color changes in the case of Cd4W2. Moreover, irradiation of Cd4Mo2 using 436 nm light induces a reversible photomagnetic effect due to the LIESST-like singlet-triplet transition at the MoIV center. Analogous photomagnetic experiments for Cd4W2 did not lead to any significant change of its magnetic moment.