Two M(II)-diphosphonate coordination polymers: structural, fluorescent and magnetic studies (M = Cu,Ca) Kui-Rong Ma Li Cao Jing-Jing Liu Shang-Ji Li 10.6084/m9.figshare.7581773.v1 https://tandf.figshare.com/articles/journal_contribution/Two_M_II_-diphosphonate_coordination_polymers_structural_fluorescent_and_magnetic_studies_M_Cu_Ca_/7581773 <p>Two examples of Cu<sup>II</sup>/Ca<sup>II</sup>-diphosphonate coordination polymers, [Cu<sub>2</sub>(L)(H<sub>2</sub>O)<sub>2</sub>]<sub>n</sub> <b>1</b> and {[Ca(L-H<sub>2</sub>)]<sub>2</sub>·2H<sub>2</sub>O}<sub>n</sub> <b>2</b> (H<sub>4</sub>L = H<sub>2</sub>O<sub>3</sub>PCH<sub>2</sub>N(C<sub>4</sub>H<sub>8</sub>)NCH<sub>2</sub>PO<sub>3</sub>H<sub>2</sub>), L-H<sub>2</sub> = O<sub>3</sub>PCH<sub>2</sub>HN(C<sub>4</sub>H<sub>8</sub>)NHCH<sub>2</sub>PO<sub>3</sub>), <i>N</i>,<i>N</i>′-piperazinebis(methylenephosphonic acid)), have been hydrothermally synthesized and characterized by elemental analysis, FT-IR, PXRD, TGA and single-crystal X-ray diffractions. Compound <b>1</b> possesses a 2-D inorganic-organic alternate arrangement layer structure, in which ligand H<sub>4</sub>L shows a never reported multi-dentate coordination mode. Compound <b>2</b> possesses a 3-D open-framework structure with 1-D channel built from 44-atom rings. Results of fluorescent measurements indicate the maximum emission band centered at 435 nm of <b>1</b> should be due to the coordination effect with metal(II) ions, and the high energy emission peaks (383, 298 nm for <b>1</b> and 378, 300 nm for <b>2</b>) could be derived from the intraligand <i>π</i>*→<i>n</i> transition station of H<sub>4</sub>L (382, 310 nm, <i>λ</i><sub>ex</sub> = 235 nm). Magnetism analysis of <b>1</b> indicated antiferromagnetic interactions being from the 1-D magnetic chain with the binuclear unit [Cu<sub>2</sub>O<sub>2</sub>].</p> 2019-01-13 02:13:32 Cu(II)/Ca(II)-diphosphonate Structure Fluorescence Magnetism