Surprisingly, coherent particles were formed in the presence of an excess of 11–13,
as confirmed by SEM, TEM, and AFM images (Fig. 19). To probe the contribution
of anion-π interaction, energy dispersion spectroscopy (SEM-EDS) analysis was
carried out, and peak for element S from naphthalene-1,5-disulfonate was also
clearly observed. Particularly, the intensity analysis suggested that the S component was mainly concentrated in the joint parts of the coherent particles. On the
other hand, experiments with naphthalene-1,5-disulfonic acid and naphthalene-1sulfonate as control compounds did not give the as-mentioned coherent particles,
demonstrating the essential role of anion-π interaction in self-assembly formation.
Diverse self-assembling structures afforded with interaction between corona[4]
arene[2]tetrazine 14 and anions of different geometries were demonstrated by Wang
and coworkers [44]. In solid state, 14 formed complexes with various anions
Fig. 18 Bisoxacalix[2]arene[2]triazines as dual building units of anion-π self-assembly
Fig. 19 Self-assembly of 11 in the absence (a) and presence (b) of naphthalene-1,5-disulfonate
10 Application of Anion-π Interaction on Supramolecular Self-Assembly
269
as confirmed by SEM, TEM, and AFM images (Fig. 19). To probe the contribution
of anion-π interaction, energy dispersion spectroscopy (SEM-EDS) analysis was
carried out, and peak for element S from naphthalene-1,5-disulfonate was also
clearly observed. Particularly, the intensity analysis suggested that the S component was mainly concentrated in the joint parts of the coherent particles. On the
other hand, experiments with naphthalene-1,5-disulfonic acid and naphthalene-1sulfonate as control compounds did not give the as-mentioned coherent particles,
demonstrating the essential role of anion-π interaction in self-assembly formation.
Diverse self-assembling structures afforded with interaction between corona[4]
arene[2]tetrazine 14 and anions of different geometries were demonstrated by Wang
and coworkers [44]. In solid state, 14 formed complexes with various anions
Fig. 18 Bisoxacalix[2]arene[2]triazines as dual building units of anion-π self-assembly
Fig. 19 Self-assembly of 11 in the absence (a) and presence (b) of naphthalene-1,5-disulfonate
10 Application of Anion-π Interaction on Supramolecular Self-Assembly
269