Aggregation, complexation with guest molecules, and mesomorphism of amphiphilic phthalocyanines having four- or eight tri(ethylene oxide) chains

Nagao Kobayashi, Ryuji Higashi, Kazuyuki Ishii, Kazuaki Hatsusaka, Kazuchika Ohta

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

Zinc and metal-free amphiphilic phthalocyanines (pcs) substituted by four or eight tri(ethylene oxide) chains (3,6, 9-trioxadecyloxy groups) {(H2(4EGpc), [Zn(4EGpc)], H2(8EGpc), and [Zn(8EGpc)] in Fig. 1)} have been prepared in order to study their aggregation in water, dioxane, and dioxane/water mixtures, their complexation phenomena with guest molecules in benzene, and mesomorphism in the neat state. In particular, tetra-substituted pcs have C(4h) symmetry and do not contain other positional isomers. [Zn(8EGpc)] forms aggregates in water and water-organic solvent mixtures; the extent of this was examined by electronic absorption and fluorescence spectroscopy, 1H NMR and fluorescence spectroscopy indicated that H2- and [Zn(8EGpc)] form inclusion complexes with quinones in benzene via hydrogen bonding. Benzoquinones with more hydroxy groups form complexes more effectively, plausibly laterally outside of the pc plane. From the higher field shift of the 1H signals of 2,2'-dihydroxy- 1,1' -binaphthyl (BINAP) in the presence of [Zn(8EGpc)], BINAP molecules were suggested to lie above or below the pc plane. The mesomorphism of H2(8EGpc), [Zn(4EGpc)], and H2(4EGpc) was studied. In the case of H2(8EGpc), the discotic hexagonal ordered columnar (D(ho)) phase was seen in the range of from room temperature to 265 °C. However, liquid-crystalline phases were not observed for H2(4EGpc) and [Zn(4EGpc)].

Original languageEnglish
Pages (from-to)1263-1271
Number of pages9
JournalBulletin of the Chemical Society of Japan
Volume72
Issue number6
DOIs
Publication statusPublished - 1999 Jun 1

ASJC Scopus subject areas

  • Chemistry(all)

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