Three novel metal-organic frameworks based on an unsymmetrical rigid carboxylate ligand for luminescence sensing of nitrobenzene derivatives and magnetic properties

Three novel metal-organic frameworks, formulated as [Co.HDCPN).4,4'-bibp)]center dot 1.5H(2)O (1), [Cd-3(DCPN)(2)(4,4'-bibp)(2)H2O]center dot 1.5H(2)O (2) and [Mn-3(DCPN)(2)(4,4'-bibp)(3)(H2O)(4)] (3) (H3DCPN = 6-(3,5-dicarboxylphenyl) nicotinic acid and 4,4'-bibp = 4,4'-bis(imidazolyl) biphenyl), have been solvothermally synthesized based on an unsymmetrical rigid carboxylate ligand. Single-crystal X-ray diffraction analysis shows that complex 1 is an sql/Shubnikov tetragonal plane network with mononuclear Co(II) ions, which is connected by O2 center dot center dot center dot H2 center dot center dot center dot O1 hydrogen bonds to generate a 3D framework. Complex 2 is a new 3D (3,10)-c network based on trinuclear Cd clusters. Complex 3 is an extended 3D (3,10)-c network based on trinuclear Mn clusters, which belongs to 3,10T3 (MOF.ttd). Complex 2 exhibits potential application for the luminescence sensing of nitrobenzene derivatives. Furthermore, the variable-temperature magnetic susceptibilities of complexes 1 and 3 indicate that they exhibit antiferromagnetic behavior and ferromagnetic behavior between metal ions, respectively.