Lanthanide metal-organic frameworks showing luminescence in the visible and near-infrared regions with potential for acetone sensing.

The luminescent properties of a family of lanthanide metal-organic frameworks LnL (Ln=Y, La-Yb, except Pm; L=4,4'-({2-[(4-carboxyphenoxy)methyl]-2-methylpropane-1,3-diyl}bis{oxy})dibenzoic acid) have been explored, and the energy-transfer process in the compounds has been carefully analyzed. The visible-emitting Tb(0.08)Gd(0.92)L and the near-infrared (NIR)-luminescent Yb(0.10)Gd(0.90)L show excellent optical performances and can be considered as fluorescent probes for acetone sensing based on luminescence quenching effects arising from host-guest interactions. Moreover, GdL exhibits a strong second harmonic generation (SHG) signal 6.1 times that of potassium dihydrogen phosphate (KDP) and an outstanding phase-matchable effect. These lanthanide compounds combining fluorescent and nonlinear optical (NLO) properties could meet further requirements as multifunctional materials.