New developments in positron and positronium chemistry

In this review an attempt will be made to critically assesses the present status of positron and postronium chemistry. Recent experimental results in liquid systems and solutions obtained by several research groups will be discussed and interpreted in terms of various existing models for positronium formation. The different parameters which are thought to be responsible for inhibition or enhancement of positronium formation will be delineated and their relative contributions to the overall effect evaluated. In the second part of the paper the various types of reactions which positrons and positronium atoms can undergo will be demonstrated by the discussion of typical reactions with various reactants in liquid systems and their implications for conventional chemistry assessed. Finally, the third section of this talk will be devoted to the discussion of the application of the positron annihilation technique to the solution of pertinent chemical problems. Selected examples from the fields of physical-, micellar-, and biochemistry where this nuclear probe has been successfully employed have been chosen to demontrate the potential use of this technique in the various areas of chemistry