Singly and doubly twisted [36]annulenes: synthesis and calculations.
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).
Mohebbi
Ali Reza
AR
Institut für Organische Chemie, Universität Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany.
Mucke
Eva-Katrin
EK
Schaller
Gaston R
GR
Köhler
Felix
F
Sönnichsen
Frank D
FD
Ernst
Ludger
L
Näther
Christian
C
Herges
Rainer
R