Steric effects in di- and tri-arylmethanes. Part IX. Electronic absorption spectra of julolidine (2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizine) and kairoline (1-methyl-1,2,3,4-tetrahydroquinoline) analogues of Michler's hydrol blue, malachite green, crystal violet, and Michler's ketone

Julolidine and kairoline analogues of some basic di- and tri-phenylmethane dyes and of Michler's ketone have been prepared and their spectra have been examined. The analogues of Michler's ketone in acid solution give charge-resonance systems by protonation of the oxygen atom, and it is suggested that nitrogen in these compounds may be sp2-hybridised.