title: Resonance-stabilized phenylazo-ene-phenylimine cations of cyclobutanetetraone derivatives.
abstract: Cyclobutenedione phenylazo-phenylamines were found to exhibit bathochromic shifts in acidic media and hypsochromic shifts in basic media, like phenylazo-phenylhydrazones. The bathochromic shifts are due to the formation of resonance-stabilized cations and the hypsochromic shifts to enolization. The phenylazo-phenylamines and their cations and anions have been studied by NMR spectroscopy.
authors.affiliation: Department of Chemistry, The American University, 4400 Massachusetts Avenue, NW, Washington, DC 20016, USA. helk@erols.com
authors.forename: Hassan S
authors.initials: HS
authors.lastname: El Khadem
authors.forename: Bruce
authors.initials: B
authors.lastname: Coxon
mesh_terms: D000814:Aniline Compounds; D003503:Cyclobutanes / Q000737:chemistry*; D007097:Imines; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013053:Spectrophotometry
chemical_list: D000814:Aniline Compounds; D003503:Cyclobutanes; D007097:Imines; D007659:Ketones