Coupling photo-, mechano- and thermochromism and single-ion-magnetism of two mononuclear dysprosium-anthracene-phosphonate complexes

Dy-III(depma)(3)(NO3)(3) (1) and Dy-III(depma)(4)(NO3)(2)(CF3SO3) (2) differ structurally by the number of depma ligands and the supramolecular interactions (pi-pi and C-H center dot center dot center dot pi, respectively) between anthracene moieties. They exhibit single-ion-magnetism which is coupled to photo-and mechanochromism that are partially reversible by thermal annealing. The changes are associated with the formation and destruction of excimers.