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Singly and Doubly Twisted [36]Annulenes: Synthesis and Calculations
Author(s) -
Mohebbi Ali Reza,
Mucke EvaKatrin,
Schaller Gaston R.,
Köhler Felix,
Sönnichsen Frank D.,
Ernst Ludger,
Näther Christian,
Herges Rainer
Publication year - 2010
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201000277
Subject(s) - annulene , antiaromaticity , twist , aromaticity , topology (electrical circuits) , cyclophane , chemistry , computational chemistry , crystallography , stereochemistry , crystallization , chemical physics , molecule , crystal structure , geometry , organic chemistry , mathematics , combinatorics
A cyclophane with a [36]annulene periphery, including four anthrylene and two phenylene units, was synthesized in a four‐step sequence using a McMurry cyclization. Upon crystallization from different solvents, four different conformations were determined by X‐ray structure analysis. Two conformations exhibit a double twist (Hückel topology) and two structures include a single twist (Möbius topology). By using DFT calculations a conformation with a triple twist (Möbius) was located. However, our calculations and the NMR spectroscopy data do not provide evidence for aromaticity (for Möbius structures) or antiaromaticity (for Hückel structures).