324
Y. Haketa et al.
showed a photo-induced crystal–crystal phase transition in the bulk state. Furthermore, negatively charged π-electronic systems prepared by the complexation of
anion-responsive molecules with an azobenzene bearing an alkanoate and an aliphatic
chain provided unique dimension-controlled assemblies, such as a photo-responsive
supramolecular gel. On the other hand, the pyrrole-based π-system–Pt
II complexes,
which showed excited-state dynamics characterized by fast intersystem crossing and
microsecond-order triplet-state lifetimes, are applicable as new chiral photocatalysts through the active use of photo-induced reactive transient states. Appropriately designed π-electronic species, some of which can be charged π-systems, can
facilitate the control of the structures, assembling modes, and electronic states by
photoirradiation. π-Electronic systems that are further designed and modified will
induce tunable functionalities and form fascinating materials possessing electronic
and optical functions [47, 48].
Acknowledgements We deeply appreciate the co-authors of the reports related with the contents in
this chapter, including Dr. Mitsuo Hara (Nagoya University), Prof. Shusaku Nagano (Rikkyo University), Prof. Takahiro Seki (Nagoya University), Dr. Ryoma Sato (RIKEN), Prof. Yasuteru Shigeta
(the University of Tsukuba), Prof. Yoichi Kobayashi (Ritsumeikan University), and Dr. Nobuhiro
Yasuda (JASRI), for their collaboration. The present work was supported by JSPS KAKENHI Grant
Number 26107007, Grant-in-Aid for Scientific Research on Innovative Areas “Photosynergetics”.
References
1. Faul CFJ, Antonietti M (2003) Ionic self-assembly: facile synthesis of supramolecular
materials. Adv Mater 15:673–683
2. Faul CFJ (2014) Ionic self-assembly for functional hierachical nanostructured materials. Acc
Chem Res 47:3428–3438
3. Binnemans K (2005) Ionic liquid crystals. Chem Rev 105:4148–4204
4. Axenov KV, Laschat S (2011) Thermotropic ionic liquid crystals. Materials 4:206–259
5. Goossens K, Lava K, Bielawski CW, Binnemans K (2016) Ionic liquid crystals: versatile
materials. Chem Rev 116:4643–4807
6. Haketa Y, Maeda H (2017) Dimension-controlled ion-pairing assemblies based on π-electronic
charged species. Chem Commun 53:2894–2909
7. Haketa Y, Maeda H (2018) Dimension-controlled π-electronic ion-pairing assemblies. Bull
Chem Soc Jpn 91:420–436
8. Webster OW (1965) Diazotetracyanocyclopentadiene and its conversion to tetracyanocyclopentadienide and pentacyanocyclopentadienide. J Am Chem Soc 87:1820–1821
9. Less RJ, McPartlin M, Rawson JM, Wood PT, Wright DS (2010) A simple approach to coordination compounds of the pentacyanocyclopentadienide anion. Chem Eur J 16:13723–13728
10. Sakai T, Seo S, Matsuoka J, Mori Y (2013) Synthesis of functionalized tetracyanocyclopentadienides from tetracyanothiophene and sulfones. J Org Chem 78:10978–10985
11. Bando Y, Haketa Y, Sakurai T, Matsuda W, Seki S, Takaya H, Maeda H (2016) Ion-pairing
assemblies based on pentacyano-substituted cyclopentadienide as a π-electronic anion. Chem
Eur J 22:7843–7850
12. Maeda H, Fukui A, Yamakado R, Yasuda N (2015) Dipyrrolyphenol as a precursor of πelectronic anion that forms ion pairs with cations. Chem Commun 51:17572–17575
13. Maeda H, Takeda Y, Haketa Y, Morimoto Y, Yasuda N (2018) Ion-pairing assemblies of πelectronic anions formed by intramolecular hydrogen bonding. Chem Eur J 24:8910–8916
Y. Haketa et al.
showed a photo-induced crystal–crystal phase transition in the bulk state. Furthermore, negatively charged π-electronic systems prepared by the complexation of
anion-responsive molecules with an azobenzene bearing an alkanoate and an aliphatic
chain provided unique dimension-controlled assemblies, such as a photo-responsive
supramolecular gel. On the other hand, the pyrrole-based π-system–Pt
II complexes,
which showed excited-state dynamics characterized by fast intersystem crossing and
microsecond-order triplet-state lifetimes, are applicable as new chiral photocatalysts through the active use of photo-induced reactive transient states. Appropriately designed π-electronic species, some of which can be charged π-systems, can
facilitate the control of the structures, assembling modes, and electronic states by
photoirradiation. π-Electronic systems that are further designed and modified will
induce tunable functionalities and form fascinating materials possessing electronic
and optical functions [47, 48].
Acknowledgements We deeply appreciate the co-authors of the reports related with the contents in
this chapter, including Dr. Mitsuo Hara (Nagoya University), Prof. Shusaku Nagano (Rikkyo University), Prof. Takahiro Seki (Nagoya University), Dr. Ryoma Sato (RIKEN), Prof. Yasuteru Shigeta
(the University of Tsukuba), Prof. Yoichi Kobayashi (Ritsumeikan University), and Dr. Nobuhiro
Yasuda (JASRI), for their collaboration. The present work was supported by JSPS KAKENHI Grant
Number 26107007, Grant-in-Aid for Scientific Research on Innovative Areas “Photosynergetics”.
References
1. Faul CFJ, Antonietti M (2003) Ionic self-assembly: facile synthesis of supramolecular
materials. Adv Mater 15:673–683
2. Faul CFJ (2014) Ionic self-assembly for functional hierachical nanostructured materials. Acc
Chem Res 47:3428–3438
3. Binnemans K (2005) Ionic liquid crystals. Chem Rev 105:4148–4204
4. Axenov KV, Laschat S (2011) Thermotropic ionic liquid crystals. Materials 4:206–259
5. Goossens K, Lava K, Bielawski CW, Binnemans K (2016) Ionic liquid crystals: versatile
materials. Chem Rev 116:4643–4807
6. Haketa Y, Maeda H (2017) Dimension-controlled ion-pairing assemblies based on π-electronic
charged species. Chem Commun 53:2894–2909
7. Haketa Y, Maeda H (2018) Dimension-controlled π-electronic ion-pairing assemblies. Bull
Chem Soc Jpn 91:420–436
8. Webster OW (1965) Diazotetracyanocyclopentadiene and its conversion to tetracyanocyclopentadienide and pentacyanocyclopentadienide. J Am Chem Soc 87:1820–1821
9. Less RJ, McPartlin M, Rawson JM, Wood PT, Wright DS (2010) A simple approach to coordination compounds of the pentacyanocyclopentadienide anion. Chem Eur J 16:13723–13728
10. Sakai T, Seo S, Matsuoka J, Mori Y (2013) Synthesis of functionalized tetracyanocyclopentadienides from tetracyanothiophene and sulfones. J Org Chem 78:10978–10985
11. Bando Y, Haketa Y, Sakurai T, Matsuda W, Seki S, Takaya H, Maeda H (2016) Ion-pairing
assemblies based on pentacyano-substituted cyclopentadienide as a π-electronic anion. Chem
Eur J 22:7843–7850
12. Maeda H, Fukui A, Yamakado R, Yasuda N (2015) Dipyrrolyphenol as a precursor of πelectronic anion that forms ion pairs with cations. Chem Commun 51:17572–17575
13. Maeda H, Takeda Y, Haketa Y, Morimoto Y, Yasuda N (2018) Ion-pairing assemblies of πelectronic anions formed by intramolecular hydrogen bonding. Chem Eur J 24:8910–8916