Preparation and Spectral Characterization of Novel Species in Matrices

A review of matrix‐isolation experiments performed in this laboratory for the past thirteen years (1992–2004) 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 HNO 3 . 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 ‐H 2 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 ‐H 2 , are also presented.