Study On The Synthesis And Application Of Novel Aromatic Compound Containing With Polypyridine Polycarboxyl Units

Luminescent lanthanide complexes have been used as catalysts, luminescent labels and gene probes, due to their peculiar properties:redox-active, high quantum yields of the emission and large Stokes shift. In the lanthanide complexes with some organic ligands, the use of pyridine-2,6-dicarboxylic acid (DPA) derivatives as sensitizers was better than using salicylic, Phenanthroline ligands. The substituted pyridine-2,6-dicarboxylic acid derivatives of Tb(Ⅲ) and Eu(Ⅲ) are stabile, luminescence intensities of these complexes are strong, and lifetime is long. They can be applied in the fields of food, iatrology and biology. In Organic molecules, the conjugation length is longer, the degree of plane is higher, which is more likely to be used as two-photon absorption materials.Two novel pyridine-2,6-dicarboxylic acid derivatives,2,6-bis(2-(2,6-dicarboxypyridin-4-yl)vinyl)pyridine and4-(2-(2,6-bis (methoxycarbonyl) pyridine-4-yl) vinyl))pyridine-2,6-dicarboxylate, were synthesized starting from4-(hydroxymethyl) pridine-2,6-dicarboxylate through multi-steps synthesis reaction, and the reactive conditions was optimized. The two compounds in which two pyridine rings connected through C=C bond has rigid planar structure with excellent electronic negotiability in the π-conjugated plane. Their stuucture were confirmed by IR and’HNMR. Yield65.5%based on4-(hydroxymethyl) pridine-2,6-dicarboxylate.In organic synthesis, carbon-carbon double bond formation is extremely important reactions. Therefore, the development of a simple, economic, and eco-friendly method is of great significance in both in practice and in theory. Two new compounds synthetic methodology were studied. The new compound2,6-bis(2-(2,6-dicarboxypyridin-4-yl) vinyl)pyridine was synthesized by two different synthesis routes, in the second synthesis method, the dichromate oxidant was replaced by potassium hexacyanoferrate (Ⅲ), and the by-product potassium hexacyanoferrate(Ⅱ) can be oxidized and recycle used, which is economic and beneficial to environmental protection.The synthesis method of4-(2-(2,6-bis (methoxycarbonyl) pyridine-4-yl) vinyl)) pyridine-2,6-dicarboxylate was optimized by organic nitrogen alkali than previous Wittig reaction. Yield was improved to59.8%than the old synthetic route. The effects of different organic nitrogen alkali on the reaction were studied.Furthermore, the Tb(Ⅲ) complexes of2,6-bis(2-(2,6-dicarboxypyridin-4-yl)vinyl) pyridine(L1) and4-(2-(2,6-bis (methoxycarbonyl) pyridine-4-yl) vinyl)) pyridine-2,6-dicarboxylate(L2) were prepared. The structure of complexes were deduced by EA and IR as Na6Tb2(L1)3·18H2O and Na6Tb2(L2)3·18H2O. The fluorescence properties of the solid complex and its solution were investigated in detail:The capacity of the ligand sensitizing the lanthanide ion is stronge. Fluorescence intensity of the Tb(Ⅲ) complex in solid state is stronger than that in the solution and the less the dipole moment of solvent molecule is, the stronger the luminescence intensity is. The ligands of2,6-bis(2-(2,6-dicarboxypyridin-4-yl)vinyl)pyridine(L1) and4-(2-(2,6-bis (methoxycarbonyl) pyridine-4-yl) vinyl)) pyridine-2,6-dicarboxylate(L2) are excellent sensitizeres to the Tb(Ⅲ).