Multi-functional fluorescent responses of cobalt complexes derived from functionalized amide-bridged ligand

Multi-functional fluorescent detection for inorganic pollutants and biological protein is important but challenging. In this work, five multi-functional luminescent coordination polymers (LCPs), [Co2(L)2(PDA)2]·H2O (1), [Co(L)(TPD)(H2O)2]·8H2O (2), [Co(L)(1,3-BDC)]·2H2O (3), [Co(L)(MIP)]·H2O (4) and [Co3(L)3(HIPA)3] (5) [H2PDA = 1,3-phenylenediacetic acid, H2TPD = 2,5-thiophenedicarboxylic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid, H2MIP = 5-methylisophthalic acid and H2HIPA = 5-hydroxyisophthalic acid] have been successfully synthesized from a naphthalene-dicarboxamide [N,N′-bis(4-methylenepyridin-4-yl)-1,4-naphthalene dicarboxamide (L)] with multi-functional spacers. 1 and 2 show 4-c sql networks. 3–5 display mab, pcu and hxg 3D frameworks, respectively. The title complexes exhibit multi-functional fluorescent responses towards metal ion (Fe3+), anions (CrO42−, Cr2O72− and MnO4−) and biological protein (bovine serum albumin). Five Co-based LCPs based on functionalized amide-bridged ligands have been obtained, which exhibit multi-functional fluorescent responses towards Fe3+, CrO42−, Cr2O72−, MnO4− and BSA. [Display omitted] •Organic ligand with multifunctional spacer were designed and synthesized.•Five new Co-based LCPs based on naphthalene-methylene-mixed bridging ligand and organic carboxylic acids were prepared.•The LCPs exhibit fluorescent quenching behavior on CrO42−, Cr2O72−, MnO4− and Fe3+.•The LCPs have good fluorescent responses for bovine serum albumin.