Fluorescent single-ion magnets: molecular hybrid (HNEt3)[DyxYb1-x(bpyda)2] (x=0.135-1)

Four single-phase isostructural mononuclear complexes (HNEt3)[DyxYb1-x(bpyda)(2)]center dot 3H(2)O (x = 1 (1), 0 (2), 0.367 (3), 0.135 (4), bpyda = 2,2'-bipyridine-6,6'-dicarboxylate) show characteristics of controllable slow relaxation and photoluminescence. The molecular hybrids 3 and 4 exhibit the Orbach process for the Dy-III component and a mixture of direct and Raman processes for the Yb-III component. The presence of paramagnetic Yb-III enhances the relaxation time of the Dy-III component, originating from the suppression of the direct process/QTM. The correlation between photoluminescence, static susceptibilities and dynamic magnetic relaxation in the hybrid species was also analysed by comparing the energy gap between the ground and first excited states to the energy barrier.