The Effect of Chemical Exchange on Energy and Phase Relaxation-Processes in Nuclear Magnetic Resonance Spectroscopy

采用核磁共振和同位素取代方法研究了离子溶液中化学交换反应的动力学和平衡性质以及局部原子排布。我们调查的影响,化学成份在NMR纵向磁化线形状恢复曲线以及核磁共振光谱利用耦合的通解表达式的时间演化纵向磁化的网站a和b(1)配体交换反应在水Al_2 (SO_4) _3解决方案(Al (H_2O) _6) ^ < 3 + > + ^ 2 _ <双箭头> (Al (H_2O) _5SO_4) ^ + + H_2O和(2)不同complex-species之间的交换反应用^<27>Al NME表征了氯铝酸盐熔体2alc1 ^-_ <双箭头> Al_2C1^-_ + Cl^-的动力学和平衡性质。应用^<25>Mg和^<31>P核磁共振研究了Mg^<2+>在ATP中与<bata>-磷结合的两个非桥接氧周围的几何结构以及Mg^<2+>与ATP的相互作用。(3)在ATP + Mg^<2+>水溶液中，被水分子分离的ATP结合的Mg^<2+>与失去第一配位球水分子的紧密结合的Mg^<2+>之间可能发生交换反应。用中子衍射仪，用Li和N同位素取代法研究了熔融LiAlCl_4和LiNO_3的结构。说明了它们之间可能的构象以及Li^+络合离子可能的配位。

The studies on the kinetic and equilibrium properties of chemical exchangereaction, and local atomic-arrangement in the ionic solutions were carried out by using nuclear magnetic resonance and isotopic substitution methods.We have investigated the influence of chemical-exchange on the line-shapes in the NMR longitudinal magnetization recovery curves as well as in the NMR spectra by using a general solution of the coupled expressions for the time evolution of the longitudinal magnetizations of sites A and B. (1) The ligand exchange-reaction in aqueous Al_2(SO_4)_3 solution[Al(H_2O)_6]^<3+>+so^2-_<double arrow> [Al(H_2O)_5SO_4]^+ + H_2O and (2) the exchange-reaction between different complex-species in chloroaluminate melts2Alc1^-_ <double arrow> Al_2C1^-_ + Cl^-was characterized about their kinetic and equilibrium properties by using ^<27>Al NME. The ^<25>Mg and ^<31>P nuclear magnetic resonance was applied to a study of geometry of Mg^<2+> around two non-bridging oxygens binding to <bata>-phosphorus in ATP and interaction of Mg^<2+> with ATP. (3) The exchange reaction in aqueous ATP + Mg^<2+> solution may take place between ATP-bound Mg^<2+> separated from ATP by a water molecule and tightly site-bound Mg^<2+> which loses the water molecule from the first coordination sphere.The structures of molten LiAlCl_4 and LiNO_3 have been investigated by means of neutron diffractometer, using the method of Li and N isotopic substitution. The possible conformation among them as well as the possible coordination by complex ion of Li^+ was illustrated.