A Cerium Organic Framework with {Cu 2 I 2 } Cluster and {Cu 2 I 2 } n Chain Modules: Structure and Fluorescence Sensing Properties.

In this work, a copper iodine module bearing a coordination polymer (CP) with a formula of [(Cu 2 I 2 ) 2 Ce 2 (INA) 6 (DMF) 3 ]·DMF ( 1 , HINA = isonicotinic acid, DMF = N , N' -dimethyl formamide) is presented. The title compound features a three dimensional (3D) structure, in which the {Cu 2 I 2 } cluster and {Cu 2 I 2 } n chain modules are coordinated by N atoms from a pyridine ring in INA - ligands, while the Ce 3+ ions are bridged by the carboxylic groups of INA - ligands. More importantly, compound 1 exhibits an uncommon red fluorescence (FL) with a single emission band maximized at 650 nm belonging to near infrared (NIR) luminescence. The temperature dependent FL measurement was applied to investigate the FL mechanism. Remarkably, 1 could be used as a FL sensor to cysteine and the nitro-bearing explosive molecule of trinitropheno (TNP) with high sensitivity, demonstrating its potential FL sensing applications for biothiol and explosive molecules.