REDUCTION BY ORGANOMETALLIC COMPLEXES
Abstract
Solutions of azobenzene (.01 M) and tricarbonylarenechromiums (.01 M) , RC6H5(CO)3, in dulute ethanolic hydrochloric acid (.01 M) under N give fair yields (up to 30%) of benzidine dihydrochloride, identified by analysis and I.R. spectrum. The reaction occurs for the substituent range R=Me,CL,H,NH2,NHMe and NMe2 and is facilitated by electron repelling groups; this is consistent with protonation at the chromium atom being assisted by charge transfer. No reduction is observed in the absence of acid so some type of protonation seems essential. More dilute solutions (.0001 M) of the complexes undergo fairly rapid decomposition in ethanolic hydrochloric acid under N with the evolution of CO and formation of free arene. Spectrophotometric studies of tricarbonylanilinechromium show an immediate fall in intensity of the 3150 angstrom band corresponding to protonation at the N atom followed by a further decrease due to decomposition; extrapolation gives a pKa value to 1.26. Results support the view that reduction by organometallic complexes is related to protonation at the metal atom.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1962
- Accession Number
- AD0296573
Entities
People
- David A. Brown
- H. Sloan
- J.p. Hargaden
Organizations
- University College Dublin