Visible and near-infrared luminescence from self-assembled lanthanide(III) clusters with organic photosensitizers

Synthesis and photophysical properties of nonanuclear lanthanide(III) clusters, H10[Ln9(hesa)16(μ-O)10(NO3)] (hesa=hexylsalicylate, Ln=Gd, Tb and Yb) were investigated. By the ligand excitation at 380 nm in methanol, the Tb cluster exhibited luminescence due to the 4f–4f transitions of Tb(III) around 487, 549, 580, 621, 646, 670, and 680 nm (5D4→7Fi: i=6, 5, 4, 3, 2, 1, 0). The Yb cluster also showed the photosensitized luminescence at around 980 nm (2F7/2→2F5/2). Especially, the Tb cluster gave a high emission quantum yield (Φs>0.90) in methanol.