Three naphthalenedisulfonate polymers with imidazole-containing ligands: Synthesis, structure and heterogeneously catalytic performance in reactions of enamination of β -dicarbonyl compounds

Three new naphthalenedisulfonate polymers, [Cd(2,6-nds)(bib)](n) (1), [Cd(1,5-nds)(bib)](n) (2), and [Cu(2,6nds)(0.5)(tpim)](n) (3), have been successfully synthesized by hydrothermal reactions of corresponding metal salts with naphthalenedisulfonate (nds) and imidazole-containing ligands 1,4-bis(imidazol-1-ylmethyl) benzene (bib) and 2,4,5-tri(4-pyridyl)-imidazole (tpim). The structures of these polymers were determined by single crystal X-ray diffraction analysis. Polymers 1 and 2 crystallize in the same space group and have similar cell parameters, and thus show same three-dimensional (3D) framework architecture. Complex 3 has the same 2D layer structure. The photoluminescent properties of the complexes 1 and 2 were investigated. Catalytic tests indicate that complex 3 has chemo-and regio-selective catalytic activity towards enamination of beta-ketoesters. (C) 2015 Elsevier B.V. All rights reserved.