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Short-Lived Intermediates

  1. Matthew J. Almond,
  2. Samantha L. Jenkins

Published Online: 15 DEC 2011

DOI: 10.1002/9781119951438.eibc0202

Encyclopedia of Inorganic and Bioinorganic Chemistry

Encyclopedia of Inorganic and Bioinorganic Chemistry

How to Cite

Almond, M. J. and Jenkins, S. L. 2011. Short-Lived Intermediates. Encyclopedia of Inorganic and Bioinorganic Chemistry. .

Author Information

  1. University of Reading, Reading, UK

Publication History

  1. Published Online: 15 DEC 2011

Abstract

Methods for the generation and detection of short-lived intermediates are discussed. These include flow systems (where a steady-state concentration of the intermediate is monitored), flash photolysis (where the intermediate is studied in real time using a very fast detection method), and matrix isolation (where the intermediate is preserved by trapping in a solid, inert host at low temperature and where conventional spectroscopic methods are used for detection). Many of the classical experiments utilizing these methods are described, but the relevance to modern chemical studies is also emphasized. The spectroscopic methods used to detect short-lived intermediates are considered. These include nuclear magnetic resonance (NMR), electron spin resonance (ESR), microwave, infrared (IR), Raman, and ultraviolet-visible absorption and emission spectroscopies. It is shown that IR remains the method of choice for matrix-isolation experiments whereas flash photolysis work tends to rely mainly upon electronic spectroscopic techniques. The use of IR spectroscopy, using tunable lasers, for flash photolysis work (at least for slightly longer-lived intermediates) is discussed. Finally two case studies are considered in detail. These are the photolysis of metal carbonyls and the formation of unusual main group compounds at high temperatures. These studies exemplify the procedures that have been used to investigate short-lived intermediates in inorganic chemistry.

Keywords:

  • matrix isolation;
  • flash photolysis;
  • flow systems;
  • nuclear magnetic resonance spectroscopy;
  • electron spin resonance spectroscopy;
  • microwave spectroscopy;
  • infrared spectroscopy Raman spectroscopy;
  • ultraviolet-visible spectroscopy;
  • laser-induced fluorescence;
  • extended x-ray absorption fine structure (EXAFS);
  • metal carbonyls;
  • main group compounds;
  • metal halides;
  • metal oxysalts;
  • rare gas chemistry