A luminescent europium MOF containing Lewis basic pyridyl site for highly selective sensing of o-, m- and p-nitrophenol

Abstract

A new luminescent two-dimensional europium metal–organic framework [Eu₆(L)₃(HL)₂(H₂O)₁₀]·10H₂O·x(solvent) (1) has been successfully prepared by the solvothermal reaction of Eu(NO₃)₃·6H₂O and the multidentate π-conjugated ligand H₄L (H₄L = (5,5′-(pyridine-2,5-diyl)-isophthalic acid)) which has a Lewis basic pyridyl site. The solid sample of 1 emits high bright red light which can be readily observed by the naked eyes when excited at 358 nm at ambient temperature. Interestingly, the luminescence of fine grinding 1 particles dispersed in ethanol can be sensitively and selectively quenched by adding trace amounts of o-, m- and p-nitrophenol (NP), which reveals that 1 can be used as a luminescence sensor for the detection of o-, m- and p-NP.