A novel pyrazolone pyridine-containing ligand,2,6-bis(1-phenyl-4-ethoxycarbonyl-5-pyrazolone-3-yl)pyridine (H2L) was de-signed and synthesized from pyridine-2,6-dicarboxylic acid (1),and its Eu(III) and Tb(III) complexes were prepared.The ligand and com-plexes were characterized in detail based on FT-IR spectra,1H NMR,elemental analysis and thermal analysis,and the formula of Ln2L3·4H2O (Ln=Eu or Tb) of rare earth complexes was confirmed.The UV-vis absorption spectra and photoluminescence properties of the complexes were investigated,which showed that the Eu(III) and Tb(III) ions could be sensitized efficiently by the ligand (H2L) and emit the photolumi-nescence with high intensity,narrow half-peak width,and monochromic light.The results indicated that the complexes showed potential as excellent luminescent materials.
Molecular iodine was first utilized for direct oxidation of α-isophorone(α-IP) to ketoisophorone(KIP) with molecule oxygen at room temperature and the effects of amount of iodine,solvents and reaction time were investigated extensively.The optimized result shows that 70.2% conversion of α-isophorone and 82.6% selectivity of ketoisophorone are obtained with 15% iodine(molar fraction) in acetonitrile under photoirradiation for 5 h.Moreover,the possible mechanism is proposed.
A novel ligand, N,N'-(2,6-pyridinedicarbonyl)bis[N-(carboxymethyl)] (L1) was designed and synthesized starting from pyri-dine-2,6-dicarboxylic acid (1). The ligand (L1) and intermediate product (3) were characterized by 1H nuclear magnetic resonance (NMR), Fourier transform infrared spectrometer (FT-IR) spectra and elemental analysis. Besides, four novel co-luminescence systems of Sm-La-pyridyl carboxylic acids: K4Sm(1-x)Lax(L1)Cl3·y1H2O, K12Sm2(1-x)La2x(L2)3 Cl6·y2H2O, K6Sm2(1-x)La2x(L3)Cl6·y3H2O and K4Sm(1-x)Lax(L4)Cl3·y4H2O (x was the mole fraction of La(III) in the mixed ions, the value was 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, respectively; y1, y2, y3, y4 were plus integer) were studied, and the mechanism of fluorescence enhancement effect was discussed detailedly.
Three new ferrocene(Fc) based receptors with pyridyl moiety, named methyl-6- ferrocenoylacetyl-2-pyridine carboxylate(FcL1), 1,1′-(2,6-bispyridyl)bis-3-ferrocenyl-1,3-propanedione(FcL2), ferrocenecarboxaldehyde-2,6-dipicolinoyhydrazone(FcL3) were synthesized, and further characterized by elemental analysis, IR spectra, UV-Vis spectra,1H and13C NMR. The electrochemical properties and ion sensing properties of FcL1, FcL2 and FcL3 were also investigated by means of cyclic voltammetry in ethanol solution with 0.1 mol/L LiClO4 as the supporting electrolyte. The E0values of the receptors increase with the scanning rate increasing at high scanning rate, and Ipa /Ipc approaches unity, indicating that the redox reaction is basically reversible. Their recognition performances to different metal cations such as Cd(Ⅱ), Co(Ⅱ), Cu(Ⅱ), Hg(Ⅱ), Mn(Ⅱ), Ni(Ⅱ), Zn(Ⅱ) show that the FcL1 is responsive to Cu(Ⅱ) with the maximum electrochemical shift of the FcL1 for Cu(Ⅱ) of about 72.0 mV, whereas the FcL2 is responsive to Cu(Ⅱ) and Mn(Ⅱ) with shift of 102 mV and 109 mV, respectively, and the FcL3 is responsive to Hg(Ⅱ) and Mn(Ⅱ) with the shift of 53.0 mV and 54.0 mV, respectively. All the results show that these receptors may have potential applications in electrochemical sensor technology, material science, and molecular devices.
