Features of Phenolsulfonphthalein and Phenolphthalein Substituted at All Ortho-Positions of Phenols with Bromine.

• TAMURA Zenzo

  School of Pharmaceutical Sciences, Showa University

• TERADA Rimi

  School of Pharmaceutical Sciences, Showa University

• OHNO Kennichi

  School of Pharmaceutical Sciences, Showa University

• MAEDA Masako

  School of Pharmaceutical Sciences, Showa University

Abstract

The influence of bromination at all the ortho-positions of phenols on the features of phenolsulfonphtalein and phenolphtalein was investigated. The absorption spectra of Bromphenol Blue (H₂BPS) in phosphate buffers demonstrated the complete opening of the lactone ring to form yellow HBPS^- at pH 1 where pK₂=3.8. The reaction of hydroxide ion with blue BPS^2- was found to produce colorless BPS(OH)^3- required heating where pK₃=9. On the contrary, the spectra of 3′,3″,5′,5″-tetrabromophenolphtalein (H₂BPP) demonstrated that the lactone ring was very stable. More than 99.5% of BPP^2- species consisted of a colorless lactone possessing two isolated phenol groups where pK₁′=6.0 and pK₂′=6.8; the reaction of hydroxide ion with BPP^2- to produce BPP(OH)^3- was slow where pK₃=10.3. These results indicate the increased acidity of phenols and the greater tendency of the central carbon atom to act as an electron acceptor.

Journal

• Analytical Sciences

  Analytical Sciences 15 (4), 339-342, 1999

  The Japan Society for Analytical Chemistry

Keywords

• Analytical Chemistry

Details

• CRID: 1390001204254952448
• NII Article ID: 10002419357
• NII Book ID: AA10500785
• DOI: 10.2116/analsci.15.339
• COI: 1:CAS:528:DyaK1MXisVSntL8%3D
• ISSN: 13482246
• ISSN: 09106340
• NDL BIB ID: 4712328
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I4712328
• Web Site: https://link.springer.com/content/pdf/10.2116/analsci.15.339.pdf
• Web Site: https://link.springer.com/article/10.2116/analsci.15.339/fulltext.html
• Web Site: http://www.jstage.jst.go.jp/article/analsci/15/4/15_4_339/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed