Synthesis, crystal structures and fluorescent properties of two new 7-iodo-8-hydroxyquinoline-5-sulfonic acid-containing polymers

Two new coordination polymers [Zn(IHQS)(4,4′-bipy)1/2(H2O)2]n (1) and [Mn(IHQS)(4,4′-bipy)1/2(H2O)2]n (2) (IHQS = 7-iodo-8-hydroxyquinoline-5-sulfonic acid) have been synthesized and characterized by single crystal X-ray diffraction. Both of them display one-dimensional chain framework in which the cage-like dimeric units formed by two metal ions, two IHQS anions and four water molecules are bridged by 4,4′-bipy. The hydrogen bonds and weak C--I···X (X = N, O, S) interactions extend the one-dimensional chains into three-dimensional supramolecular frameworks. The fluorescent properties of both polymers and IHQS were measured in solid state at room temperature. The results indicated that the emission spectra of the two polymers could be assigned to intraligand transition.