Diverse Cd(II) coordination polymers with a multidentate N-donor ligand 3,5-bis(4-pyridyl)-4-(3-pyridyl)-1,2,4-triazole and pseudohalide anions

Abstract

Assemblies of 3,5-bis(4-pyridyl)-4-(3-pyridyl)-1,2,4-triazole ( L 3 ) with Cd(II) in the presence of different pseudohalide anions [N 3 − , dca (dicyanamide) or SCN − ] produce three distinct coordination polymers, i.e. {[Cd 5 ( L 3 ) 2 (H 2 O) 2 (N 3 ) 10 ](CH 3 OH) 2 (H 2 O) 4 } n ( 1 ), [Cd( L 3 ) 2 (dca) 2 ] n ( 2 ) and [Cd( L 3 ) 2 (SCN) 2 ] n ( 3 ). In 1 , the N 3 − anions with three different coordination modes bridge the Cd(II) ions to form 2-D inorganic layers, which are extended by the tridentate L 3 ligands to result in a 3-D coordination framework. In 2 and 3 , the anion (dca or SCN − ) takes the terminal coordination and L 3 acts as the bidentate bridge, resulting in 1-D double-strand chain for 2 and double-strand chiral helix for 3 . Thermal stability and fluorescence for 1–3 are also presented. This work presents the syntheses, structures, and properties of three Cd(II) coordination polymers with a tripyridyltriazole ligand, which exhibit distinct 3-D coordination network and 1-D double-strand chain or chiral helix arrays directed by the pseudohalide anions. ► Three distinct Cd(II) coordination polymers are constructed based on a novel tripyridyltriazole tecton. ► Their polymeric structures are regulated by different pseudohalide anions. ► Solid state fluorescent emissions are available at room temperature.