Publication Details (including relevant citation information):
Arkivoc, (vii) 2010, 179
We report an improved synthesis method for the production of cyclophanes 5, 6, and 7 in higher
yields of 71, 98, and 99%, respectively, compared to the previously reported 40, 30, and 70% yields,
- Cyclophanes C5, C6, and C7, called corrals, have different cavity sizes determined by
the number of methylene spacers varying from three to five; they form inclusion complexes with
neutral aromatic molecules. Therefore, we have studied their interactions with anthracene (A) using
absorption, fluorescence, and Fourier transform infrared spectroscopies. The average association
constants of each cyclophane with anthracene in dichloromethane were determined to be (log K)
- 4.24 + 0.10, 4.81 + 0.05, and 4.25 + 0.03 for the C5/A, C6/A, and C7/A systems, respectively.
The binding of anthracene is favored by C6 over C5 and C7 in solution, possibly due to
increased stability of the equilibrium geometry of the C6/A complex. Upon complexation low
frequency spectral shifts for several transitions associated with anthracene and corral molecules
were observed. The slight spectral shifts are in accord with weak intermolecular forces prevalent
in the studied corral/anthracene complexes.
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