Spectroscopic Study on the Photophysical Properties of Lanthanide Complexes with 2, 2′-Bipyridine-N, N′-dioxide

Five novel lanthanide (Eu3+, Tb3+, Gd3+, Sm3+ and Dy3+) complexes with 2, 2'-bipyridine-N, N'-dioxide (bipyO2) were synthesized and characterized by elemental analysis, IR spectrum. The triplet state energy of bipy O2 was determined to be 22275 cm(-1) with the phosphorescence spectrum of bipy O2 and its gadolinium complex. The photophysical properties of these complexes indicated that the triplet state energy of the ligand is suitable for the sensitization of the luminescence of Eu3+, Tb3+, Sm3+ and Dy3+, especially of Tb3+.     

Measurement of RLT and ATL in the 4He(e, e’p)3H reaction at pmiss of 130-300 MeV/ c

We have measured the ⁴He(e, ep)³H reaction at missing momenta of 130-300 MeV/c using the three-spectrometer facility at the Mainz microtron MAMI. Data were taken in perpendicular kinematics to allow us to determine the response function R_LT and the asymmetry term A_TL. The data are compared to both relativistic and non-relativistic calculations.     

Effects of phonon-phonon coupling on low-lying states in neutron-rich Sn isotopes

Starting from an effective Skyrme interaction we present a method to take into account the coupling between one- and two-phonon terms in the wave functions of excited states. The approach is a development of a finite rank separable approximation for the quasiparticle RPA calculations proposed in our previous work. The influence of the phonon-phonon coupling on energies and transition probabilities for the low-lying quadrupole and octupole states in the neutron-rich Sn isotopes is studied.     

Beta-decay of 71Co and 73Co

A decay spectroscopy study of the neutron-rich cobalt isotopes has been performed using fragmentation of a ⁸⁶Kr³⁶⁺ beam and the new LISE2000 spectrometer at GANIL. For ⁷¹Co and ⁷³Co, the -delayed radiation has been observed for the first time, and the half-lives were found to be 79(5) ms and 41(4) ms, respectively. Features of the decay are discussed qualitatively in terms of nuclear models.     

Non-empirical calculations of NMR indirect carbon-carbon coupling constants. Part 6: propellanes

A full set of carbon-carbon coupling constants have been calculated at the SOPPA level in the series of six most representative propellanes. Special attention was focused on spin-spin couplings involving both bridgehead carbons, and these data were rationalized in terms of the multipath coupling mechanism and hybridization effects. Many unknown couplings in the propellane frameworks were predicted with high reliability.     

Sol-Gel Synthesis of Transparent Alumina Gel and Pure Gamma Alumina by Urea Hydrolysis of Aluminum Nitrate

-Alumina was synthesized by a sol-gel method with the aluminum ion hydrolysis control performed by urea. The initial saturated Al³⁺/urea solution presented urea coordinated with the aluminum ion, as shown in the ¹³C NMR and ²⁷Al NMR spectra and longitudinal relaxation times, T ₁, from the latter. The substitution of water molecules in the Al³⁺ coordination shell by urea controlled the hydrolysis process and provided an extensive nucleation during the initial steps of the aluminum hydroxide formation due to urea thermolysis at 90°C. The resulting sol, composed of Al(OH)₃ nanoparticles, coalesced and became a transparent gel permeated by a solution of urea and the polycation ion [Al₁₃O₄(OH)₂₄(H₂O)₁₂]⁷⁺. The freshly prepared gel was transformed, under heating at 300°C, directly to -alumina, characterized by FTIR, ²⁷Al-MAS-NMR and S_BET techniques, without - or -phases, as a consequence of the high degree of homogeneity of the -alumina precursor.     

Capillary Coated with Layer-by-Layer Assembly of γ-Zirconium Phosphate/ Lysozyme Nanocomposite Film for Open Tubular Capillary Electrochromatography Chiral Separation

A new capillary coating of alternate -zirconium phosphate lysozyme fabricated for open-tubular electrochromatography enantioseparation. The chiral compounds D, L-tryptophan tested were enantiomerically resolved. The influences brought by experimental parameters, such as organic modifier, temperature, applied voltage and pH of running buffer on the performance of the column, were investigated.     

Synthesis of 4-phenyl-3,4-dihydro-β-carboline

4-Phenyl-3,4-dihydro--carboline was prepared using the Bischler—Napieralski reaction on -phenyltryptamine.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 486–487, November–December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis of o-phenylphenol from cyclohexanone over platinum supported on calcined Mg/Al hydrotalcite

A kinetic model is proposed to account for the effect of oxygen during catalyst premodification on the rate and enantioselectivity in hydrogenation of methyl pyruvate over cinchonidine modified platinum catalysts.This revised version was published online in December 2005 with corrections to the Cover Date.