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Cover Picture (Angew. Chem. Int. Ed. Engl. 7/1986)
Publication year - 1986
Publication title -
angewandte chemie international edition in english
Language(s) - English
Resource type - Reports
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 0570-0833
DOI - 10.1002/anie.198605831
Subject(s) - annulene , cover (algebra) , electron delocalization , ring (chemistry) , planar , chemistry , combinatorics , crystallography , physics , delocalized electron , stereochemistry , computer science , mathematics , computer graphics (images) , organic chemistry , engineering , mechanical engineering
The cover picture shows pieces of a puzzle of substructures of novel, cyclic conjugated [4n]‐π‐electron systems. The fragments are shown in the colors of the solutions of the respective “antiaromatics”. Pleiaheptalene (yellow) is the first peri ‐annelated [4n]‐π‐electron system without aromatic partial structures. 9b‐Methyl‐9b H ‐benz[ cd ]azulene (blue), a tricyclic [12]annulene, has an almost planar perimeter and shows pronounced paratropism. In contrast, 1,2,5,7‐tetra‐ tert ‐butyl‐ s ‐indacene (red fluorescence), a planar annelated 12π‐electron system, exhibits only a slight paratropic ring‐current effect with extensive delocalization. More about these novel compounds is reported by K. Hafner et al. on page 630.