1. Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294; Organic Analysis Laboratories, Toray Research Center, Inc., 3-3-7 Sonoyama, Otsu, Shiga 520-8567, Japan; Department of Macromolecular Science, Osaka University, Toyonaka, Osaka 560-0043, Japan; and Department of Polymer Science, The University of Southern Mississippi, Hattiesburg, Mississippi 39406