T. Koga et al., Synthesis, electronic spectra, and crystal structural properties of fluorinated [3(3)](1,3,5)cyclophanes, ORG LETT, 3(10), 2001, pp. 1419-1422
[GRAPHICS]
Trifluoro and hexafluoro[3(3)](1,3,5)cyclophanes 3 and 4 were synthesized w
ith TosMIC coupling as a key reaction. The pi-pi* absorption bands show blu
e shifts as the number of fluorine atoms is increased. In the crystalline s
tate, characteristic stacking with the fluorinated benzene rings facing eac
h other is observed in both cases.