Three Different Co(II) Metal-Organic Frameworks Based on 4,4′-Bis(imidazolyl)diphenyl Ether: Syntheses, Crystal Structure and Photocatalytic Properties

Three Co(II) metal-organic frameworks (Co-MOFs) build by 4,4 '-bis(imidazolyl)diphenyl ether (bidpe), m-Phthalic acid (H(2)mpa), 5-Nitroisophthalic acid (H(2)nmpa) and 5-sulfonatobenzene-1,3-dicarboxylate (H(2)smpa), namely: [Co(mpa)(bidpe)](n)(1), [Co(nmpa)(bidpe)](n)(2), {[Co-1.5(smpa)(bidpe)(2)]center dot 1.5H(2)O center dot 0.25DMA}(n)(3), were synthesized under same solvothermal condition. The compounds have been characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction, thermogravimetric (TG) analysis and powder X-ray diffraction (PXRD). The single-crystal X-ray diffraction analysis reveals that compound1shows a 4-connectedsqlnet with Schlafli point symbol (4(4)center dot 6(2)). Compound2displays a 3, 5-connected net with Schlafli point symbol (4(2)center dot 6(7)center dot 8)(4(2)center dot 6). Compound3possesses a 3-connected net with Schlafli point symbol (4(2)center dot 6). The photocatalytic investigations indicate that compounds1-3afford good photocatalytic capabilities in degradation of methylene blue (MB) and methylene violet (MV). Furthermore, the possible photocatalytic mechanisms have been discussed.