Zinc(ii)-based coordination polymer encapsulated Tb(3+) as a multi-responsive luminescent sensor for Ru(3+), Fe(3+), CrO(4)(2−), Cr(2)O(7)(2−) and MnO(4)(−)

A zinc(ii)-based coordination polymer (CP), namely [Zn(modbc)(2)](n) (Zn-CP) (modbc = 2-methyl-6-oxygen-1,6-dihydro-3,4′-bipyridine-5-carbonitrile), has been synthesized and characterized. Single-crystal structural determination reveals that Zn-CP is a two-dimensional framework structure with tetranuclear homometallic Zn(4)(modbc)(4) units cross-linked by modbc. The excellent luminescence as well as good stability of Zn-CP do not enable it to have selective sensing capability for different ions. After encapsulation of Tb(3+) in Zn-CP, the as-obtained fluorescent functionalized Tb(3+)@Zn-CP maintained excellent luminescence as well as stability, which made it a highly selective and sensitive multiresponsive luminescent sensor for Ru(3+), Fe(3+), CrO(4)(2−), Cr(2)O(7)(2−), and MnO(4)(−) with high sensitivity, good anti-interference performance, and quick response time (∼10 s). The detection limits are 0.27 μM, 0.57 μM, 0.10 μM, 0.43 μM and 0.15 μM, respectively. A possible sensing mechanism was discussed in detail.