A Series of Cyanoacetato Copper(II) Coordination Polymers with Various N,N '-Ditopic Spacers: Structural Diversity, Supramolecular Robustness, and Magnetic Properties

作者：Suvanvapee Porntiva; Boonmak Jaursup^*; Klongdee Fatima; Pakawatchai Chaveng; Moubaraki Boujemaa; Murray Keith S; Youngme Sujittra

来源：Crystal Growth & Design, 2015, 15(8): 3804-3812.

DOI：10.1021/acs.cgd.5b00453

Five novel copper(II) coordination polymers containing cyanoacetate (cna) anion with various N,N'-ditopic spacers [Cu(cna)(2)(pyz)](n) (1), [Cu(cna)2(bpy)(H2O)(2)](n) (2), [Cu(cna)(2)(dpe)](n) (3), [Cu(cna)(2)(dpe)](n)(H2O)(n) (4), and [Cu(cna)(2)(bpa)](n) (5) (when pyz = pyrazine, bpy = 4,4'-bipyridyl, dpe = 1,2-di(4-pyridyl)ethylene, and bpa = 1,2-di(4-pyridyl)ethane) were structurally and spectroscopically characterized. Compound 1 shows a two-dimensional (2D) sheet structure constructed from mu(2)-1,3(syn,anti) coordinative mode of cyanoacetate and mu(2)-pyz linking adjacent Cu(II) centers. Compound 2 exhibits a one-dimensional (1D) polymeric chain which is formed by mu(2)-bpy bridging between [Cu(cna)(2)(H2O)(2)] units, whereas compounds 3-5 reveal 1D ladder-like structures which are built from double-mu(2)-dpe/bpa spacers connecting neighboring Cu(II) cyanoacetate dimers. Weak interactions such as hydrogen bonding and N...p and/or CH...pi interactions join the adjacent layers of 1 or polymeric chains of 2-5 to stabilize overall supramolecular networks. The thermal stabilities of 1-5 were investigated. Interestingly, compound 2 reveals a robust supramolecular framework constructed by 1D polymeric chains during thermal dehydration and rehydration processes, which has been further verified by spectroscopic techniques, elemental analyses, thermogravimetric analysis, and X-ray powder diffraction. Moreover, this behavior is not observed in the isomorphous series containing Co(II) and Ni(II) ions. The magnetic properties of 1 and 3 exhibit very weak antiferromagnetic interactions between Cu(II) centers.

• 出版日期2015-8