Synthesis, structure, and photoluminescence properties of coordination polymers of 4,4′,4′′,4′′′-tetrakiscarboxyphenylsilane and 3,5-bis(1′,2′,4′-triazol-1′-yl)pyridine

Abstract

Three coordination polymers (CPs) incorporating both 4,4′,4′′,4′′′-tetrakiscarboxyphenylsilane (H₄tcps) and 3,5-bis(1′,2′,4′-triazol-1′-yl)pyridine (btap), namely [Co₂(tcps)(btap)(H₂O)₃] (1), [Co₃(Htcps)₂(btap)(H₂O)₆] (2) and [Cd₃(Htcps)₂(btap)(H₂O)₆] (3), were synthesized by a solvothermal method. Compound 1 features a 3D (3,4,5)-connected framework with the (6·7⁵·8⁴)(6⁴·8²)(7²·9) topology. Compounds 2 and 3 are isostructural, which display an unusual 1D + 3D → 3D polythreaded supramolecular architecture with the 1D chain inserted into the channels of the two-fold interpenetrating 3D motif. Hydrogen bonds among the 3D anionic motif and the 1D cationic motif further stabilize the compounds. The structure of compounds 2 and 3 is a 3D 3-connected framework with the point symbol (10³)₄. The luminescence properties of compound 3 in their solid state and as dispersed in various solvents were investigated. Luminescence studies have revealed that compound 3 exhibits high sensitivity and stable anti-interference towards Fe³⁺ and Cu²⁺ cations in aqueous solution.