Self-assembled hybrid solids of luminescent Ru(II) polypyridyl complexes and polyoxometalates

Two new hybrid compounds, [Ru(bpy)3][W6O19] (1) and [Ru(bpy)3]2[Mo8O26]∙6H2O (2) (bpy = 2, 2′-bipyridyl) have been synthesized hydrothermally and characterized using single crystal X-ray diffraction, TG, IR, FL, and UV–vis spectroscopy. Their crystal structures exhibit unique supramolecular interactions between [Ru(bpy)3]2 + and polyoxometalate units. Compound 1 shows anion–π interactions between the Linqvist unit W6O192 − and the aromatic ring of the [Ru(bpy)3]2 + complex. In compound 2, no significant anion–π interactions between the β-isomer of [Mo8O26]4 − and the [Ru(bpy)3]2 + unit were observed. Upon excitation at the λmax (450 nm) of the MLCT band of the [Ru(bpy)3]2 +, compound 1 shows an emission centered at 599 nm and compound 2 displays an emission centered at 613 nm.