Chapter 2. Nuclear magnetic resonance spectroscopy

Abstract

IntroductionAs emphasised in previous reports in this series,*-3 any attempt to cover the literature which has appeared over a three year period on a topic as all embracing as n.m.r. spectroscopy must, of necessity, be very selective. The areas chosen for consideration in the present account are similar to those discussed previously'-3 and, thus, are inclined towards some of the more physical topics pertaining to molecular science.Comprehensive accounts of all chemically related fields of n.m.r. investigations are to be found in the Specialist Periodical Reports on n .~. r .~ These volumes contain extensive references to the primary literature and lists of books, reviews and symposia proceedings which provide a means of keeping in contact with recent developments in the n.m.r. technique and its applications.Noteworthy recent advances are included in the present account together with a few key references. An attempt is made to omit those publications which, in the main, represent a hortus conclusus. A glossary of abbreviations used in this chapter is given on page 45. Instrumental Aspects of N.M.R.Developments continue to be reported in various instrumental aspects of n.m.r.. The present account concentrates on some of those relating to pulse sequences, 2D n.m.r. and n.m.r. imaging.A book dealing with the principles of FT n.m.r. has appeared' as well as one covering applications of 1 D and 2D methods to biological systems6 Additional mention may be made of three extensive One of these deals with a coherent theoretical framework for 2D n.m.r. experiments.' The application of 1 D multiple ' G. Figure 1 Schematic representation of screw pulses, in the case of 4 2 phase shifts. Each transition type iies along one of the four axes. The R and L axes carry 'R-type' and Z-type' one-quantum transitions, the P axis carries populations and zero-quantum transitions ('P-type') and the D axis carries double-quantum ('D-type') transitions. It is thus easyto follow the transfer of information among them from left to right (Reproduced with permission from J. Magn. Reson., 1985, 63, 255) pulse techniques to liquids is covered in another review' while the third one provides a comprehensive survey of the various 2D n.m.r. techniques together with a critical account of their applications.'