Synthesis And Properties Of Novel Pyridine 2,6 - Dicarboxylic Acid Derivatives Of Tb (iii) Complexes

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 others.Since the lanthanide complexes are chiral,we can get more information about structure of biologic molecule through measuring Circularly Polarized Luminescence Spectra.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 was long.They can be applied in the fields of food,iatrology and biology.Two novel pyridine-2,6-dicarboxylic acid derivatives,4-(2-(2,6-bis(methoxycarbonyl) pyridine-4-yl)vinyl))pyridine-2,6-dicarboxylate (DVDPA)and 1,5-bis(pyridine-2,6-dicarboxylate)thiocarbohydrazone (DTDPA),were synthesized starting from pyridine-2,6-dicarboxylic through methoxyl,hydroxylmethyl,oxidate and Wittig reaction,and the reactive conditions of Wittig reaction was optimized.The DVDPA ligand in which two pyridine rings connected through C=C bond has rigid planar structure with excellent electronic negotiability in the n-conjugated plane.Two ligands and their intermediates were confirmed by IR and ¹HNMR.Furthermore,the Tb(Ⅲ)complexes of DVDPA and DTDPA were prepared.The structures of complexes were deduced by EA and IR as Na₆Tb₂(DVDPA)₃·18H₂O and Na₆Tb₂(DTDPA)₃·23H₂O.The fluorescence properties of the solid complexes and their solutions were investigated in detail:The capacity of the DVDPA ligand sensitizing the lanthanide ion is stronger than that of the DTDPA ligand.Fluorescence intensity of the Tb(Ⅲ)complexes 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 DVDPA ligand is a excellent sensitizer to the Tb(Ⅲ). The schiff base containing Thiocarbamide Group has antibacterial, anticancer and antituberculosis biological activity.The DTDPA is a kind of Schiff bases including sulphur.The bactericidal activities of compounds DTDPA and its complex were studied.The results indicate that DTDPA ligand has not acaricidal activities to some bacterium,but the bactericidal activity of the complex is superior to that of the ligand.