1. Contribution from the Department of Chemistry, Columbia University, New York, New York 10027; DuPont Central Research & Department, Experimental Station, Wilmington, Delaware 19880; Lehrstuhl fuer Umweltmesstechnik, Universitaet Karlsruhe, 76128 Karlsruhe, Germany; Department of Chemistry, University of Alabama, Tuscaloosa, Alabama 35487-0336; William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352; Department of Chemistry,...