Titrations in non-aqueous media: Part XVIII. Observation of the benzidine rearrangement reaction in acetonitrile


GUNDUZ T., KILIC E., KENAR A., OZTAS S. G.

Analyst, cilt.114, sa.6, ss.727-730, 1989 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 114 Sayı: 6
  • Basım Tarihi: 1989
  • Doi Numarası: 10.1039/an9891400727
  • Dergi Adı: Analyst
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.727-730
  • Anahtar Kelimeler: Benzidine rearrangement reaction, Potentiometrie titration, Titration in acetonitrile, Titration in non-aqueous media
  • Ankara Üniversitesi Adresli: Evet

Özet

When titrated potentiometrically in acetonitrile 1 mol of phenylhydrazine reacts with 1 mol of perchloric acid, whereas 1 mol of 1,2-diphenylhydrazine reacts with 2 mol of perchloric acid. This is an indication that the benzidine rearrangement reaction occurs under these conditions. In order to support this view, the salts formed during the titration were filtered off and neturalised with diethylamine. The neutralised material was recrystallised from pure ethanol and was shown to be benzidine by infrared and UV - visible spectrophotometry. Benzidine is formed when 1,2-diphenylhydrazine undergoes the benzidine rearrangement reaction. Chromatographic methods were also used to explain, at least in part, the mechanism of the reaction. From the results obtained it was concluded that the benzidine rearrangement reaction was occurring and that it proceeded through a monoprotonated 1,2-diphenylhydrazine species rather than a diprotonated species as proposed by other workers. This is the first benzidine rearrangement reaction to be observed in a non-aqueous medium such as acetonitrile. © 1989, Royal Society of Chemistry. All rights reserved.