Reversible switching between self-assembled homomeric and hybrid capsules
We present here the reversible, guest-controlled disproportionation of homomeric and hybrid capsules using photochemistry. The supramolecular containers are self-assembled from shallow and deep cavitand modules.
Lux, Jacques,Rebek, Julius
supporting information
p. 2127 - 2129
(2013/03/28)
NMR studies of bond order in distorted aromatic systems
The 4JH-C=C-Me coupling constant has been previously established1,2 as a probe of bond order. This has now been used to examine the bond orders of compounds containing severely distorted benzene nuclei. In the case of 3,4-di-tert-butyltoluene, no electronic distortions in the aromatic ring can be detected by this method. A series of moderately to severely distorted paracyclophanes show no perturbation of electronic structure, with the possible exception of 8-methyl[6]paracyclophane, which exhibits a barely significant deviation from unstrained values. These conclusions are supported by the results of SCF-MO calculations.
Ionization Energies of Methyl-substitutedParacyclophanes
The photoelectron (PE.) spectra of thirteen methyl-substitutedparacyclophanes have been recorded and analyzed, to asses the influence of methylsubstitution on their ionization energies.It is shown that this influence is qualitatively and quantitatively the same as for benzenes and other ?-systems.Comparison with the previous results obtained for the r>cyclophanes (r=2 to 6) strongly suggests that the hyperconjugative model for alkyl-group/?-system interactions is more appropriate than the inductive one.