Preparation and Spectral Characterization of Novel Species in Matrices

Abstract

A review of matrix-isolation experiments performed in this laboratory for the past thirteen years (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)) is given; the work emphasizes the preparation and spectral characterization of novel species of atmospheric interest, and the significance of detection of some species is discussed. A previous review (J. Chin. Chem. Soc. 1992, 39, 503) covers work from 1981 to 1991. Various methods for production of novel species, including reaction in the gaseous phase, laser photolysis of a single precursor in situ, reaction of a molecule with an atom or radical in a matrix cage and reaction of a molecule with an electronically excited molecule, are discussed. The effect of secondary photolysis on products is illustrated with formation of various conformers of HOONO from photolysis of HNO3. The advantage of investigating electronic transitions that are difficult to observe in the gaseous phase and the mode and site selectivity of photodissociation for species in a matrix cage are also discussed. New developments involving use of p-H2 as a matrix host, including the introduction of a pulse-deposition method for use at~5 K and the exploration of internal rotation of larger molecules in solid p-H2, are also presented.