Preparation and spectral characterization of novel species in matrices

A review of matrix-isolation experiments performed in this laboratory for the past thirteen years (19922004) is given; the work emphasizes the preparation and spectral characterization of novel species of at mospheric interest, and the significance of detection of some species is discussed. A pre viousre view (J. Chin. Chem. Soc. 1992, 39, 503) covers work from 1981 to 1991. Various methods for production ofnovel species, including reaction in the gasecus phase, laser photolysis of a single pre cur sorin situ, reaction of a molecule withan atom or radical in a matrix cage and reaction of a molecule with an electronically excited molecule, are dis cussed. Theef feet of sec ondaryphotolysis on products is il lus trated with formation of various conformers of HOONO from photolysis of HNO₃. The advantage of investigating electronic transitions that are difficult to ob serve in the gaseous phase and the mode and site selecivity of photodissociation for species in a matrix cage are also discussed. New developments in volv inguse of p-H ₂ as a matrixhost, including the in tro due tion 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.