Two Water-Stable Zn(II) Coordination Polymers as Luminescent Sensors for Detection of Uric Acid in Serum, MnO<sub>4</sub><sup>–</sup>, and Cr(VI) Oxo-Anions in Tap Water
Fang-Hua Zhao, Rui Feng, Shuqi Li, Jingjing Zhang, Wen-Cui Yu, Zhong‐Lin Li
Abstract
Two novel coordination polymers (CPs), [Zn 2 (μ-OH) 2 (μ-1,5-NDS-κ 2 O: O ′)(μ-Mbimb-κ 2 N: N ′)] n ( 1 ) and {[Zn(CH 3 COO-κ 1 O )(μ-bbimb-κ 2 N: N ′) 1.5 ](1,5-NDS) 0.5 } n ( 2 ), were synthesized by hydrothermal reaction of Zn(Ac) 2 ·2H 2 O with 1,5-naphthalenedisulfonate (1,5-NDS 2– ), 1,4-bis(2-methyl-1 H -imidazole-1-yl)butane (Mbimb), or 1,4-bis(1 H -benzimidazol-1-yl)butane (bbimb). In the crystal structure of 1, the Zn(II) centers are connected by μ-OH – anions into an infinite –[Zn(OH)] n – chain, which is further linked by Mbimb and 1,5-NDS 2– to form a 3D dia network. In 2, the Zn(II) centers are linked by bbimb ligands into a 2D (6,3) brick wall layer with Ac – as dangling arms threaded into the space of adjacent layers, resulting in a 2D → 3D polythreading structure. Luminescent studies reveal that both CPs have excellent luminescence stability and can selectively detect uric acid (UA), MnO 4 –, and Cr(VI) oxo-anions in aqueous solutions with high quenching efficiency. The limits of detection toward UA, MnO 4 –, CrO 4 2–, and Cr 2 O 7 2– are 0.46, 4.33, 5.50, and 1.60 μM for CP 1 and 5.63, 2.84, 7.60, and 2.90 μM for CP 2, respectively. Moreover, the two CPs can also serve as luminescence sensors to detect UA in serum and MnO 4 – and Cr(VI) oxo-anions in tap water. The luminescent films of the CPs were also prepared for visual detection of UA, MnO 4 –, CrO 4 2–, and Cr 2 O 7 2– with the naked eye.