The synthesis of the novel host compound carrying two spirobenzopyran groups was described.Its structure was confirmed by（）1H NMR,IR and elemental analysis.It was shown that the novel host can recognize lanthanide ions selectively with significant spectral shifts in visible region and enhanced absorbance.Thus,the compound can be used to recognize lanthanide ions by naked eyes. The selectivity was relative to size-fit effect.The order of spectral changes was Yb3+>Er3+>Gd3+>Dy3+>Eu3+>Pr3+>La3+,which is opposite to the order of the radii of lanthanide ions.We discussed the possible binding mechanism with analyzing the different UV-Vis spectral changes resulted by addition of the investigated ions.
