Angewandte Chemie International Edition
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Cover Picture (Angew. Chem. Int. Ed. Engl. 10/1995)
The cover picture shows the arrangement of two 1:1 complexes composed of a cyclic zinc porphyrin tetramer (Zn4−1) and a central meso-tetra-4-pyridyl-porphyrin unit (H2-Py4P) in the solid state (view along the c axis; purple = N, blue = C, yellow = Zn). The central porphyrin ligand, which is coordinated to each zinc center in Zn4−1 through an N atom of a pyridyl unit, locks the five-porphyrin assembly in a single conformation. NMR spectra indicate that the complex H2-Py4P·Zn4−1 prefers to adopt a tub-shaped geometry reminiscent of cyclooctatetraene. The picture was produced with the program Insight II from Biosym Technologies of San Diego using a Silicon Graphics Workstation. We would like to thank Dr. Robert Thomas and Prof. Dr. François Diederich (ETH Zürich Switzerland) for their help in producing this picture. Further details of the structure and fluorescence properties of this multicomponent system are reported by S. Anderson et al. on pp. 1096ff.