Effect of pH/Auxiliary Ligand on the Structures of Coordination Compounds Based on a Novel Ligand 2,6-Bis(pyrazin-2-yl)pyridine-4-carboxylate

Four new coordination compounds, [Zn（bppc）;（H;O）;]·3 H;O（1）, [Zn2（bppc）2（mbdc）(H;O)4]·7 H;O（2）, [Zn（bppc）2（H;O）2]n·n（m-Hbdc）·n（H;O）(3), [Zn2（bppc）(btc)（H;O）3]n·5 n H;O（4）(Hbppc = 2,6-bis（pyrazin-2-yl）pyridine-4-carboxylate, H2（m-bdc） = 1,3-benzenedicarboxylic acid, H3 btc = 1,3,5-benzene-tricarboxylic acid), have been hydrothermally synthesized and structurally characterized. Compound 1 shows a mononuclear structure and 2 shows a dinuclear structure. Compound 3 is a one-dimensional chain structure, which is extended into a 3D supramolecular network by intermolecular hydrogen interactions. In 4, a 1D loop-like chain is connected by（btc）3-anions to generate a 2D layer structure. The structure differences of 1;show that the p H and aromatic acid as auxiliary ligand have important influence on the final structures.iAdditionally, the luminescent properties of 1;have been investigated with fluorescent spectra in the solid state, and 1;display a strong fluorescent emission at room temperature and have potential applications as fluorescent-emitting materials.