ethynylene (o-OPE) moiety. Such moiety, besides being an active UV-chromophore,
is quite prone to chiral folding in the presence of chemical substituents imparting
chiral twists. Besides, the special carbophilic interaction of some metals with the
same moiety makes it belong to the class of metallo-foldamers.
In Fig. 10.5, we report the CPL spectra of three examples of o-OPE compounds,
recently studied in collaboration with Cuerva et al. The first compound (A) is stapled
with a 2,3-butanediol fragment in para position to the o-OPE system and the two
stereogenic centers impart a M-helicity to the o-OPEs moiety [38]; the second one
(B) is terminated by two (S)-phenyl-sulfoxides still imparting M-helicity to the oOPE system. For the second system also longer o-OPE terms, containing up to eight
o-OPE units were investigated [46]. The affinity to Ag in the two cases is 12,000 M
–1
Fig. 10.4 (Left): ECD (top) and UV/absorption (bottom) spectra. (Right): CPL (top) and fluorescence (bottom) spectra for aqueous suspensions of +ICD and ÀICD insulin fibrils stained with ThT,
in aqueous suspensions. The traces correspond to molar ratio ThT:insulin ¼ 1:2 and 1:10.
Excitation wavelength 440 nm (see Ref. [45])
10 Structural and Electronic Information Drawn. . .
227
is quite prone to chiral folding in the presence of chemical substituents imparting
chiral twists. Besides, the special carbophilic interaction of some metals with the
same moiety makes it belong to the class of metallo-foldamers.
In Fig. 10.5, we report the CPL spectra of three examples of o-OPE compounds,
recently studied in collaboration with Cuerva et al. The first compound (A) is stapled
with a 2,3-butanediol fragment in para position to the o-OPE system and the two
stereogenic centers impart a M-helicity to the o-OPEs moiety [38]; the second one
(B) is terminated by two (S)-phenyl-sulfoxides still imparting M-helicity to the oOPE system. For the second system also longer o-OPE terms, containing up to eight
o-OPE units were investigated [46]. The affinity to Ag in the two cases is 12,000 M
–1
Fig. 10.4 (Left): ECD (top) and UV/absorption (bottom) spectra. (Right): CPL (top) and fluorescence (bottom) spectra for aqueous suspensions of +ICD and ÀICD insulin fibrils stained with ThT,
in aqueous suspensions. The traces correspond to molar ratio ThT:insulin ¼ 1:2 and 1:10.
Excitation wavelength 440 nm (see Ref. [45])
10 Structural and Electronic Information Drawn. . .
227