From ladder, net to framework: Coordination polymers based on Zn(ii)/Cd(ii) ions and mixed bicarboxyl- and bipyridine-containing linear ligands

Abstract

The simultaneous use of bicarboxylate- and bipyridine-containing linear ligands to react with d¹⁰ metals affords four new polymeric compounds, [Zn(cis-chdc)(bpp)]·6H₂O (1), [Zn(cis-chdc)(bpmp)] (2), [Cd₂(cis-chdc)₂(bpmp)(H₂O)₂] (3) and [Cd₃(tp)₃(bpp)₂]•2DMF•6H₂O (4) (H₂chdc = 1,4-cyclohexanedicarboxylic acid; bpp = 1,3-bis(4-pyridyl)propane; bpmp = N,N′-bis(4-pyridylmethyl)piperazine; H₂tp = terephthalic acid), which have been structurally characterized by elemental analysis, IR, TG, powder X-ray diffraction and single-crystal X-ray diffraction. Compound 1 possesses a 1-D ladderlike structural feature, compounds 2 and 3 show two different 2-D wavelike networks with the same (4•4) network topology, and compound 4 exhibits a 3-D open framework with (4²⁴•6⁴) framework topology (similar to the CsCl-type body-centered cubic lattice). The structural features and the dimension evolution of the four compounds, along with the influence of nodes and mixed linear ligands are presented and discussed. The fluorescent properties of the four compounds are also investigated.