Two Series of Isostructural Coordination Polymers with Isomeric Benzenedicarboxylates and Different Azine Based N,N鈥?Donor Ligands: Syntheses, Characterization and Magnetic Properties

详细信息    查看全文

• 作者：Biswajit Bhattacharya ; Dilip Kumar Maity ; Rajarshi Mondal ; Enrique Colacio ; Debajyoti Ghoshal
• 刊名：Crystal Growth & Design
• 出版年：2015
• 出版时间：September 2, 2015
• 年：2015
• 卷：15
• 期：9
• 页码：4427-4437
• 全文大小：806K
• ISSN：1528-7505

文摘

Seven coordination polymers (CPs) with two types of framework structures, namely, {[M(4-bpdb)(1,3-bdc)]路(4-bpdb)_0.5}_n [M = Mn (1), Fe (2), and Co (3)], and {[M(4-bpdh)(1,4-bdc)]}_n (M = Mn (4), Fe (5), Co (6), and Cd (7)] have been synthesized through the slow diffusion technique using 1,3-bdc and 1,4-bdc ligands with two different azine based N,N鈥?donor linkers [1,3-bdc = benzene-1,3-dicarboxylate, 1,4-bdc = benzene-1,4-dicarboxylate, 4-bpdb = N,N鈥?bis-pyridin-4-ylmethylene-hydrazine and 4-bpdh = N,N鈥?bis-(1-pyridin-4-yl-ethylidene)-hydrazine]. Their structures have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra, and powder X-ray diffraction (PXRD) analysis. Compounds 1鈥?b>3 are isostructural and feature a two-dimensional (2D) framework structure formed by pillaring the one-dimensional [M(1,3-bdc)]_n double chains through 4-bpdb linkers. In all cases of compounds 1鈥?b>3, free 4-bpdb linkers are present in the lattice and lattice 4-bpdb ligands are involved in 蟺鈥撓€ and C鈥揌路路路蟺 interactions with bridging 1,3-bdc and 4-bpdb ligands, to afford three-dimensional (3D) supramolecular structures. Compounds 4鈥?b>7 are also isostructural and here the bridging of 1,4-bdc with the divalent metal centers forms a 2D layer of [M(1,4-bdc)]_n which is further pillared by 4-bpdh to form a 3D pillared-layer framework. Variable temperature magnetic measurements of two sets of isostructural complexes (1鈥?b>3 and 4鈥?b>7) have been carried out. Compounds 1鈥?b>6 clearly indicate the existence of a weak antiferromagnetic interaction between the metal ions through the bridging 1,3-bdc and 1,4-bdc ligands. The magnetic properties depend strongly on the nature of the metal center. The luminescence spectra of the complexes have been measured, which indicates a ligand based emission for all seven compounds.