1. Contribution from the Department of Chemistry, The City College and The City University of New York, 138th Street at Convent Avenue, New York, New York 10031-9198, Department of Chemistry, University of North Dakota, Abbott Hall Room 236, 151 Cornell Street Stop 9024, Grand Forks, North Dakota 58202-9024, and Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401-9403