I. Yamaguchi, K. Seo and Y. Kawashima, “Synthesis of Dihydroxyoligophenylenes Containing π-Deficient or π- Excess Hetero-Aromatic Rings and Their Solvatochromic Behavior,” Tetrahedron, Vol. 34, No. 7, 2010, pp. 6725- 6732. doi:10.1016/j.tet.2010.06.087

has been cited by the following article:

• TITLE: Synthesis and Solvatochromic Behavior of Hexaphenylbenzenes and Indeno[1,2-b]fluorene Derivatives with Hydroxy Groups

  AUTHORS: Isao Yamaguchi, Kenta Tsuchie

  KEYWORDS: Hexaphenylbenzene; Indeno[1, 2-b]fluorene; Donor Number; Photoluminescence; Solvatochromism

  JOURNAL NAME: International Journal of Organic Chemistry, Vol.2 No.3, September 25, 2012

  ABSTRACT: Hexakis(4-methoxyphenyl)benzene (HPB-OMe(1)) and hexakis(2,6-dimethyl-4-methoxyphenyl)benzene (HPB-OMe(2)) were synthesized via organometallic complex catalysis. The treatment of HPB-OMe(1) with FeCl3 caused cyclodehydrogenation at two positions to yield an oligophenylene with an indeno[1,2-b]fluorene structure (IF-OMe). Deprotection of the methoxy groups of these compounds was conducted by treatment with BBr3. Deprotonation of the OH groups of HPB-OH(1), HPB-OH(2), and IF-OH through treatment with NaH caused a bathochromic shift in the absorption and photoluminescence (PL) peaks. The bathochromic shift of the deprotonated species increased with the donor number (DN) of the solvents. These observations can be explained as the consequence of intramolecular charge transfer (ICT) from the ONa groups to the inner benzene rings.