1. Inorganic and Organometallic Chemistry; University of Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
2. Dutch Polymer Institute (DPI), P. O. Box 902; 5600 AX Eindhoven Netherlands
3. Stratingh Institute; University of Groningen; Nijenborgh 4 9747 AG Groningen Netherlands
4. Department of Chemistry; University of Manitoba; Winnipeg MB R3T 2N2 Canada