Synthesis, Charaterization, Fluorescence Properties And Interaction With Bovine Serum Albumin Of Rare Earth Perchlorate With Phenacylmethyl, P-Tolyl Sulfoxide

Four solid binary complexes of rare earth perchlorate with phenacylmethyl. p-tolyl sulfoxide and twelve ternary complexes of rare earth perchlorate with phenacylmethyl, p-tolyl sulfoxide as the first ligand and Benzoic Acid,2,2’-Dipyridyl,1,10-Phenanthroline as second ligands have been synthesized and characterized. By elemental analysis, rare earth coordination titration and TGA-DSC studies, the composition of the binary complexes is suggested as REL7·(C1O4)3-6H2O (RE=Sm, Eu. Tb. Dy; L=C6H5COCH2SOC6H4CH3) and the trinary complexes are suggested as REL6·L’·(C104)2·nH2O (RE=Sm,Eu, Tb. Dy; L’=C6H5COO"; L=C6H5COCH2SOC6H4CH3; n=7.6); REL6·L’·(C1O4)3·6H2O (RE=Sm,Eu, Tb. Dy; L’=Dipy. phen:L=C6H5COCH2SOC6H4CH3). The study on IR spectra and’HNMR spectra indicate that phenacylmethyl. p-tolyl sulfoxide bonded with RE3+ions by the oxygen atom in sulfinyl group. The second ligand Benzoic Acid bonded with RE3+ions by one oxygen atom in carbonyl group. The second ligands2.2’-Dipyridyl and1,10-Phenanthroline bond with RE3+ions by the nitrogen atom respectively. The molar conductivities of binary complexes, sulfoxide-2,2’-Dipyridyl and sulfoxide-1,10-Phenanthroline in DMF solution indicate that three CIO4’are not coordinated with RE3+. The molar conductivities of sulfoxide-Benzoic Acid in DMF solution indicate that two CIO4’ are not coordinated with RE3+. The fluorescence spectra illustrate that both of the Sm3+, Eu3+. Tb3+, Dy3+complexes display characteristic metal-centered fluorescence in solid state. Compared with the binary complexes, Sm3+. Eu3+ternary complexes and Dy3+-Benzoic Acid ternary complexes exhibited stronger fluorescence. When the second ligand is Benzoic Acid, the characteristic emission intensity of the ternary Sm3+complexes is the strongest. which is1.95times as great as that of the binary Sm3+complexes. This is because the introduction of the second ligands can more effective to absorb energy and transport the energy to RE3+ion through the indirect or direct way. at the same time, the second ligands can play the role of energy transfer channels. Therefore, the sulfoxide ligand and the second ligand can occur mutual synergistic effect in the energy transfer process. Phosphorescent spectrum of ligand showed that the relationship of the excited state of samarium, europium, terbium, and dysprosium and the triplet state of ligand T1and T2. The fluorescent decay curves illustrate that the fluorescence lifetime of the four series of rare earth complexes is proportional to the fluorescence emission intensity. Meanwhile, the calculation of fluorescence quantum yield of europium binary and ternary rare earth complexes shows that a positive correlation is found between the fluorescence quantum yield of the Eu3+complexes and the product of the fluorescence lifetime and ΣI0J/I01The interaction of phenacylmethyl, p-tolyl sulfoxide rare earth binary and ternary complexes and bovine serum albumin (BSA) are studied by fluorescence spectrum of BSA. The studies indicate that the reaction between rare earth complexes and BSA is a static quenching procedure. At room temperature, the binding site number n and binding constant Ka with BSA are calculated, which show that rare earth complexes and BSA have strong binding. The rare earth complexes can be transported by BSA. Therefore, it is expected to become a protein fluorescence probe.