The nuclear magnetic resonance relaxtion phenomenon is associated with molecular motion. In recent years, Same authors have studied the states of molecular motion and the activation energies and then proceeded to stud...The nuclear magnetic resonance relaxtion phenomenon is associated with molecular motion. In recent years, Same authors have studied the states of molecular motion and the activation energies and then proceeded to study the molecular structure by means of measuring the relaxation times. Therefore, the using of the pulse Fourier transform NMR spectrometer for measuring the nuclear magnetic resonance spin-lattice relaxation time T1 has become an important method for the analyses of molecular structures and the study of molecular dynamics. Michacl Epstein et al. have studied the calcium binding site of trypsin by the proton relaxation rate. In this paper by展开更多
<正> In this paper the determination of the ~1H chemical shift of pyridines with different substituents by NMR and estimation of equilibrium constants K_a for protonation of various pyridines in aqueous solution...<正> In this paper the determination of the ~1H chemical shift of pyridines with different substituents by NMR and estimation of equilibrium constants K_a for protonation of various pyridines in aqueous solution according to the pH values at the middle points are carried out. Thus, the electronic effect of substituents can be deduced from the K_a values.展开更多
文摘The nuclear magnetic resonance relaxtion phenomenon is associated with molecular motion. In recent years, Same authors have studied the states of molecular motion and the activation energies and then proceeded to study the molecular structure by means of measuring the relaxation times. Therefore, the using of the pulse Fourier transform NMR spectrometer for measuring the nuclear magnetic resonance spin-lattice relaxation time T1 has become an important method for the analyses of molecular structures and the study of molecular dynamics. Michacl Epstein et al. have studied the calcium binding site of trypsin by the proton relaxation rate. In this paper by
文摘<正> In this paper the determination of the ~1H chemical shift of pyridines with different substituents by NMR and estimation of equilibrium constants K_a for protonation of various pyridines in aqueous solution according to the pH values at the middle points are carried out. Thus, the electronic effect of substituents can be deduced from the K_a values.