Structural diversity of cobalt(II) coordination compounds involving bent imidazole ligand: A route from 0D dimer to 3D coordination polymer

Mixed ligand approach could be successfully applied to design porous three-dimensional coordination polymers, involving 1,3-bis(imidazol-1-yl)benzene (1,3-bib) as ligand. Five novel Co(II) compounds with different dimensionality have been synthesized. Utilizing only 1,3-bib in the solvothermal reaction with Co(II) salts, only molecular dimer Co2(bib)2Cl4 or 1D polymer Co2(1,3-bib)2(NO3)2 could be synthesized. Copolymerization technique using additional linear dicarboxylates 1,4-benzenedicarboxylate (1,4-bdc) or 2,6-naphthalenedicarboxylate (2,6-ndc) facilitates the formation of 2D layered coordination polymers Co(1,3-bib)(1,4-bdc) and Co(1,3-bib)(2,6-ndc). Utilizing 4,4′-biphenyldicarboxylate (4,4′-bpdc) as a co-linker, a 3D metal–organic framework Co3(1,3-bib)(4,4′-bpdc)3 (DUT-58, DUT – Dresden University of Technology), possessing two interpenetrated uninodal 8-connected frameworks, has been obtained. DUT-58 exhibits a specific surface area of 1208 m2/g and adsorbs 27 mg/g hydrogen (maximum excess value at 30 bar and 77 K), 0.18 g/g n-butane (at 293 K) and 72 mg/g methane (maximum excess value at 60 bar and 298 K).

Mixed ligand approach could be successful applied to design porous three-dimensional coordination polymer Co3(1,3-bib)(4,4′-bpdc)3 (DUT-58, DUT – Dresden University of Technology) involving 1,3-bis(imidazol-1-yl)benzene (1,3-bib) and 4,4′-biphenyldicarboxylate (4,4′-bpdc) as ligands. DUT-58 possesses two interpenetrated uninodal 8-connected frameworks and exhibits a specific surface area of 1208 m2/g.Figure optionsDownload as PowerPoint slideHighlights
► A route to porous cobalt based MOF involving bent imidazole ligand has been developed.
► A novel microporous material DUT-58 with specific surface area of 1208 m2/g has been synthesized.
► DUT-58 adsorbs 27 mg/g H2 (30 bar and 77 K), 0.18 g/g n-butane (at 298 K) and 72 mg/g CH4 (at 60 bar 298 K).