Zinc coordination polymers with 1-(3-aminopropyl)-imidazole as bridging bidentate unit

The reaction of Zn(SCN)2 with one or two equivalents of 1-(3-aminopropyl)-imidazole (api) yields the coordination polymers [Zn(SCN)2(api)]n (1) and [Zn(SCN)2(api)2]n (2), respectively. Single-crystal X-ray diffraction analysis reveals one-dimensional polymeric chain structures for both compounds. The structure of 1 consists of tetrahedral Zn(SCN)2(api)2 units linked by one molecule 1-aminopropyl imidazole in an unsymmetric mode, i.e., each metal center is coordinated by an imidazole nitrogen as well as a nitrogen of the aminopropyl group. The metal ions in 2 display an octahedral coordination geometry with each Zn(SCN)2(api)2 unit linked by two molecules of the imidazole, thus, exhibiting two imidazole and two amino groups in the coordination sphere. The polymers were further characterized by IR-, 1H NMR- and 13C NMR-spectroscopy.