Gold-Colored Organic Crystals Formed from an Azobenzene Derivative

• Matsumoto Akiko

  Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science

• Kawaharazuka Maho

  Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science

• Takahashi Yutaka

  Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science

• Yoshino Norio

  Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science

• Kawai Takeshi

  Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science Center for Colloid and Interface Science (CCIS), Tokyo University of Science

• Kondo Yukishige

  Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science Center for Colloid and Interface Science (CCIS), Tokyo University of Science

Abstract

The azobenzene derivative 4,4’-bis{1-[2-(N,N-dimethylamino)]ethoxy}azobenzene has been found to form gold-colored plate-like crystals. The thin film obtained by accumulating the crystals has a maximum specular reflectance of ca. 15% for visible light. To investigate the structure of the gold-colored crystals, UV-vis, X-ray diffraction (XRD), and IR analyses were performed. UV-vis measurements show that the molecules in the crystal produce J-aggregates. Furthermore, XRD measurements estimated the long-range d-spacing for the crystal as 1.51 nm. These results indicate that the azobenzene moieties are oriented diagonally against the crystal surfaces. When the crystals are placed in a desiccator (humidity 40%) for 1 d, their color changes from gold to yellow. IR measurements show that the gold-colored crystals contain crystallized water, while there are no water molecules in the yellow crystals, in which the structure of the J-aggregates is disrupted. These results show that the crystallized water molecules are essential for the formation of the J-aggregates and the resultant gold luster.

Journal

• Journal of Oleo Science

  Journal of Oleo Science 59 (3), 151-156, 2010

  Japan Oil Chemists' Society

Keywords

• gold crystal
• azobenzene
• J-aggregate
• thin film

Details

• CRID: 1390001204090845568
• NII Article ID: 130000160352
• NII Book ID: AA11503337
• DOI: 10.5650/jos.59.151
• ISSN: 13473352
• ISSN: 13458957
• ISSN: http://id.crossref.org/issn/13458957
• NDL BIB ID: 10560857
• Web Site: http://id.ndl.go.jp/bib/10560857
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I10560857
• Web Site: https://www.jstage.jst.go.jp/article/jos/59/3/59_3_151/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed