1. Department of Chemistry, The Scripps Research Institute, La Jolla, California
92037, United States
2. Department
of Chemistry, University of California, Merced, California 95344,
United States
3. Departamento
Crystalografia-Mineralogia,
Facultad Geologia, Universidad Complutense, 28040 Madrid, Spain
4. Syncom BV, Kadijk 3, 9747 AT Groningen,
The Netherlands