Supercharged

Superelectrophiles and their chemistry 

George A Olah and Douglas A Klumpp 

New Jersey, US; Wiley 2007 | 301pp | ?65.95 (HB) ISBN 9780470049617 

Reviewed by Ken Wade

In a long and illustrious career, Nobel Laureate George Olah, director of the Loker Hydrocarbon Research Institute, US, has made many seminal contributions to chemistry, notably transforming our understanding of carbocationic organic reactions in highly acidic media. An important breakthrough in his work was to recognise that such solvents not only facilitated the ionisation of species RX into electrophilic carbocations R⁺ and anions X^- by Lewis acidic solvation of the latter, but also activated the cations R⁺ by converting them into the ’superelectrophiles’ discussed in this book. The enhanced reactivity of acyl cations [RCO]⁺ or nitronium cations [NO₂]⁺in superacidic media stems from the formation therein of the superelectrophilic dications [RCOH]²⁺ or [ONOH]²⁺. 

Once Olah had recognised that such doubly- (occasionally more highly-) charged species could form in highly acidic solutions, the subject expanded rapidly. Its present status is revealed in this authoritative text by Olah and his former postdoctoral research assistant, Douglas Klumpp, now an independent researcher in the field. They explain how superelectrophiles can be studied in the gas phase and in solution, and helpfully list ab initio calculated energies, structures and NMR parameters for nearly 200 species, including carboxonium and carbocationic systems and many nitrogen-, phosphorus-, sulfur- and halogen-based systems. They tell us how to make superelectrophiles, and discuss the formation, structures and reactions of specific systems classified by the proximity of their cationic centres, whether close (gitonic) or distant (distonic). 

This book has implications for synthetic and mechanistic organic chemistry, enzyme chemistry and catalysis, and inorganic chemistry too.