Two-dimensional Cd(ii) coordination polymer encapsulated by Tb3+ as a reversible luminescent probe for Fe3+†
Abstract
A two-dimensional luminescent cadmium(II) coordination polymer, [Cd(modbc)2]n (Cd-P); modbc = 2-methyl-6-oxygen-1,6-dihydro-3,4′-bipyridine-5-carbonitrile, was successfully synthesized by a solvothermal reaction and fully characterized. Cd-P exhibited excellent luminescence emission, and detected Cu2+, Co2+, Fe2+, Hg2+, Ni2+ and Fe3+ ions with high sensitivity and showed good anti-interference performance. After encapsulation of Tb3+ ions in Cd-P, the as-obtained fluorescent functionalized Tb3+@Cd-P maintained distinct chemical stabilities in different pHs and metal salt solutions. Subsequently, we explored the potential application of Tb3+@Cd-P as a probe for Fe3+ ions. A new and convenient method for individual identification of Fe3+ ions by the combination of Cd-P and Tb3+@Cd-P was successfully established. A possible sensing mechanism is discussed in detail.