TY - JOUR
T1 - Systematic studies on side-chain structures of phthalocyaninato-polysiloxanes
T2 - Polymerization and self-assembling behaviors
AU - Yoneda, Satoru
AU - Sakurai, Tsuneaki
AU - Nakayama, Toru
AU - Kato, Kenichi
AU - Takata, Masaki
AU - Seki, Shu
PY - 2015/1/1
Y1 - 2015/1/1
N2 - A series of dihydroxysilicon phthalocyanines having soluble side chains were synthesized and their bulk-state polymerization capability was investigated. Detailed spectroscopic study of the obtained phthalocyaninato-polysiloxanes revealed that strong electron donating ability and small steric hindrance of the peripheral substituents are the dominant factors to afford high-molecular weight polymers. The polymers show the behaviors of columnar liquid crystal (LC), which is clarified by the presence of clear X-ray diffraction patterns with a hexagonal lattice and birefringent textures in polarized optical microscopy. Because of the siloxane covalent bonds through central silicon atoms, phthalocyaninato-polysiloxanes accommodate one-dimensional phthalocyanine arrays with strong π-electronic couplings, thus exhibiting colmnar LC property even for the derivatives carrying short peripheral chains and leading to the relatively higher density of π-electron systems in the materials. This tendency is different from typical discotic small molecules that require optimum side chain structures for LC formation.
AB - A series of dihydroxysilicon phthalocyanines having soluble side chains were synthesized and their bulk-state polymerization capability was investigated. Detailed spectroscopic study of the obtained phthalocyaninato-polysiloxanes revealed that strong electron donating ability and small steric hindrance of the peripheral substituents are the dominant factors to afford high-molecular weight polymers. The polymers show the behaviors of columnar liquid crystal (LC), which is clarified by the presence of clear X-ray diffraction patterns with a hexagonal lattice and birefringent textures in polarized optical microscopy. Because of the siloxane covalent bonds through central silicon atoms, phthalocyaninato-polysiloxanes accommodate one-dimensional phthalocyanine arrays with strong π-electronic couplings, thus exhibiting colmnar LC property even for the derivatives carrying short peripheral chains and leading to the relatively higher density of π-electron systems in the materials. This tendency is different from typical discotic small molecules that require optimum side chain structures for LC formation.
KW - columnar phase
KW - liquid crystal
KW - one-dimensional polymer
KW - phthalocyanine
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U2 - 10.1142/S1088424614501053
DO - 10.1142/S1088424614501053
M3 - Article
AN - SCOPUS:84928546110
VL - 19
SP - 160
EP - 170
JO - Journal of Porphyrins and Phthalocyanines
JF - Journal of Porphyrins and Phthalocyanines
SN - 1088-4246
IS - 1-3
ER -