Erbium bis(pentafluorophenyl) phosphinate: a new hybrid material with unusually long-lived infrared luminescence

Bis(pentafluorophenyl) phosphinic acid, (C6F5)(2)PO2H, forms thermally stable, anhydrous salts with rare earth ions such as Er3+ and Y3+; these materials adopt polymeric structures. The erbium(III) salt displays photoinduced luminescence at 1,545 nm, decay of which is mediated by erbium-erbium energy migration. The average luminescence lifetime, <tau > = 44 ms, is remarkably long for a solid erbium complex with organic ligands. This is attributed to the exclusion of solvents by the bulky ligands and the absence of any C-H bonds or other high frequency oscillators that could cause vibrational quenching.