K. Muller et al., BELT-SHAPED CYCLOPHANES VIA PHOTODIMERIZATION OF PHENANTHRO-CONDENSED[18]ANNULENES, Journal of organic chemistry, 61(16), 1996, pp. 5474-5480
A novel cyclophane type can be obtained by photocyclodimerization reac
tions of condensed [18]annulenes. Quantitative yields in pure columnar
liquid crystalline phases and high yields in 10(-6) M solution raise
the inquiry about the unusual dimerization mechanism in this process.
Concentration-dependent measurements of the emission and excitation sp
ectra and the fluorescence lifetimes reveal a ground state aggregation
in solution even at very low concentrations.