1. Institute of Organic Chemistry, Polish Academy of Sciences, ul Kasprzaka 44/52, 01-224 Warsaw, Poland; Institute of Polymer and Dye Technology, Technical University of Łódź , ul Stefanowskiego 12/16, 90-924 Łódź, Poland; and Center for Macromolecular Engineering, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213