Studies On Methodology And Application Of Dynamic Nuclear Magnetic Resonance

It is well-known that NMR plays a very important role in structural analysis and dynamic investigation of molecules. Compared to structural analysis which has achieved tremendous progresses, NMR dynamical studies have been less concerned in the past decades. In this dissertation, dynamical NMR methodology and applications are studied. The involved methods are exchange, diffusion and relaxation spectroscopy, focusing on four points: (1) The pulse sequence for heteronuclear multiple quantum diffusion experiments is modified by taking into account the systematic errors; (2) Hydrolysis of acetonitrile to acetamide is, in first time, verified to be catalyzed by bisilver(I) cryptate complex in acetonitrile solution using 2D pseudo-DOSY combined with other 2D NMR techniques. The possible reactive mechanism is proposed based on the observation of intermediate in 2D NOESY/EXSY; (3) Exchange of benzene molecules between those inside and outside of micelles as well as ligand exchange kinetics of binuclear tin(IV) complex is studied by two dimensional NMR exchange spectroscopy; (4) Interactions between anti-inflammary drugs and human serum albumin(HSA) are investigated using versatile NMR methods such as diffusion coefficient and relaxation rate measurements.Recently, NMR diffusion experiments have aroused much attention. However, inhomogeneous magnetic field and imperfect gradient often result in measurement error. Thus, it is of great significance to improve the pulse sequences available. In this dissertation, the systematic error in the measurements of self-diffusion coefficients using NMR multiple quantum spectroscopy (MQSY) method has been eliminated by bipolar composite gradient pulse (usually called BPP) that consists of a radio-frequency (RF) pulse sandwiched by two gradient pulses with equal intensities but with opposite polarities. Examples are given for heteronuclear double quantum, triple quantum and quadruple quantum diffusion measurements...