Spin exchange between paramagnetic particles is one of the few elementary bimolecular processes in solutions that is readily accessible to detailed experimental studies and to strict theoretical description. Due to this fact spin exchange is now widely used in solving various problems of chemistry, physics, and molecular biology. Spin exchange allows one to study in detail elementary acts of collisions of molecules. By use of spin exchange one can obtain quantitative information on collision rates of molecules in solutions, steric hinderance in collisions, electrostatic interactions in collisions of charged particles, and overlap of electron orbitals in collisions. Par ticularly valuable is the possibility of using spin exchange to study col lisions in such complex systems as polymer solutions, multicomponent mix tures, heterogeneous mixtures, and especially biological systems. This monograph contains a comprehensive description of spin exchange in solutions. It consists of four chapters. The introductory chapter contains a brief summary of the physical principles of spin exchange and outlines the range of its main applications. In this chapter a historic background of research in this field is also given. The second chapter contains a com prehensive presentation of the theory of spin exchange including that of its spectroscopic manifestations. The third chapter is devoted to a detailed description of the technique of experimental studies of spin exchange. The last - the fourth - chapter summarizes the results of experimental studies of spin exchange and considers various applications of spin exchange in che mistry, molecular physics, and biology.

Inhalt

Introduction.- 2. Theory of Spin Exchange.- 2.1 Exchange Interaction Between Two Paramagnetic Particles.- 2.2 Qualitative Description of Spin Exchange Process.- 2.3 Formal Kinetics of Spin Exchange in Magnetically Dilute Solutions.- 2.4 Spectroscopic Manifestations of Spin Exchange.- 2.5 Theory of Sudden Collisions.- 3. Experimental Measurement of Spin Exchange Rate.- 3.1 Experimental Measurement of Spin Exchange Rate Constants from ESR Spectra.- 3.2 Other Methods of Measuring the Spin Exchange Rate Constants.- 3.3 Separation of Exchange and Dipole-Dipole Contributions to Concentration Broadening of ESR Lines.- 3.4 Separation of the Cases of Weak and Strong Exchange.- 4. Spin Exchange in Chemistry and Biology.- 4.1 Study of Diffusion Collisions in Solutions.- 4.2 Estimation of the Energy of Exchange Interaction During Collisions.- 4.3 Collisions of Charged Particles.- 4.4 Biological Applications of Spin Exchange.- Paramagnetics Used as Spin Probes.- List of Frequently Used Notations and Abbreviations.- References.