Construction of a High-Nuclearity Elliptical Yb(III) Nanoring: NIR Luminescent Response to Metal Ions and Nitro Explosives

One 14-metal Yb(III) nanoring [Yb-14(HL)(2)L-20(DMF)(8)(H2O)(8)] (1) with a size of about 1.1 x 2.5 x 2.7 nm was synthesized from a tridentate ligand. Under the excitation of ligand absorption bands, 1 exhibits the NIR luminescence of Yb(III) and displays high luminescence sensitivity and selectivity to Co(II), Cu(II), and 2,4,6-trinitrophenol (PA) at the parts per million level. The K-SV values of 1 to Co(II), Cu(II), and PA are 6.0 x 10(4) M-1, 3.8 x 10(4) M-1, and 6.9 x 10(4) M-1, respectively. 1 exhibits high luminescent sensitivity to PA even in the presence of other explosives.