Six New Co-Coordination Polymers Based on a Tripodal Carboxylate Ligand

• Published in: Crystal growth & design 2012-07, Vol.12 (7), p.3610-3618
• Main Authors: Cui, Jiehu, Li, Yizhi, Guo, Zijian, Zheng, Hegen
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Organic compounds; Other materials; Physics; Specific materials; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg3004323

Six new compounds of partially or wholly deprotonated 3,5-bi(4-carboxy-phenoxy)-benzoic acid (H3BCPBA), namely, {[Co(H2BCPBA)2(H2O)4]} n (1), {[Co(HBCPBA)(bipy0.5)2·(H2O)]} n (bipy = 4,4′-bipyridine) (2), {[Co3(BCPBA)2(dpe)·(μ2-H2O)4]·2H2O·2DMF} n (dpe = 1,2-di-4-pyridyleth-ene) (3), {[Co3(BCPBA)2(pdp)·(μ2-H2O)4]·2DMF} n (pdp = 4-[(E)-4-pyridinylazo]pyridine) (4), {[Co3(BCPBA)2(bpe)·(μ2-H2O)4]·2DMF} n (bpe = 1,2-bis(4-pyridyl)ethane) (5), {[Co2(HBCPBA)2 (bpp)·(μ2-H2O)2]·H2O·2DMF} n (bpp = 1, 3-bis(4-pyridyl)propane) (6) were synthesized in the presence or absence of auxiliary ligand. Their structures have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectroscopy, and thermogravimetric analysis. Compound 1 is a zero-dimensional structure. Compound 2 is a two-dimensional (2D) sheet structure with two 2D → 2D interpenetration frameworks. Compounds 3–5 are similar and possess three-dimensional (3D) networks with two 3D → 3D interpenetration frameworks. In compound 6, H3BCPBA and bpp ligands link Co centers to generate a 2D sheet structure which is further connected by intermolecular hydrogen bonds to form a 3D supramolecular structure. The photochemical properties are performed in the solid state at room temperature. Magnetic susceptibility measurements indicate that compounds 2–6 exhibit antiferromagnetic coupling between adjacent Co(II) ions.