Structure characterization of 1:1 adducts of metal(II) halides and piperazine

From the simple hydro/solvothermal reactions, two 1:1 adducts of MX₂ and piperazine (pip) [CdI₂(pip)] 1 and [CoCl₂(pip)] 2 were prepared. Both were characterized by elemental analyses, IR spectra, ultra-violet visible spectra, thermogravimetric analyses and X-ray single-crystal diffraction. With pip as the bridges, the 1-D linear CdI₂ chains are extended into a 2-D layered compound 1, while the mononuclear CoCl₂ units are linked into a 1-D zigzag-type chain compound 2. The fluorescence emission spectrum indicates that compound 1 possesses fluorescence property with the peaks at 373 nm () and 410 nm ().