Photosensitized luminescent lanthanide (III) clusters encapsulated with polyphenylsilsesquioxane

An inorganic-organic lanthanide (III) cluster encapsulated with polyphenylsilsesquioxane (PPSQ), which would be a suitable luminescent material for violet LEDs excitation will be reported. The cluster with adjacent 9 terbium (III) ions in close proximity (3.6∝3.7 A), in which lanthanide (III) ions are stabilized with organic photosensitizing compounds, 16 hexylsalicylates, has been successfully introduced. The terbium (III) cluster was highly soluble in PPSQ and had high thermostability. By the ligand excitation of the cluster-doped PPSQ at around near-UV light region (e.g., 360-380 nm), the terbium (III) cluster displayed strong green luminescence with a maximum intensity at 547 nm (intra-4f transition of terbium (III) ion: 5D4 →7F5). It was likely that energy transfer from excited hexylsalicylates to terbium (III) ions mediated sensitized emission of Tb (III) ions in PPSQ. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)