Département de chimie moléculaire

The title dyes, [FcCH=CHC5H4NCH2C6H4Bu-tert-4]X (X = BPh4-, ClO4-; Fc = ferrocenyl; C5H4N = 4,1-pyridinio), developed for rapid screening of catalysts, are intensely colored, but bleach on exposure to visible light in soln. Detailed study shows that on irradn. these alkene dyes first undergo a trans-cis isomerization, then give an irreversible bleaching via decompn. Both dyes show color dependence on the nature of the anion as a result of ion-pairing, which affects the intensity and position of the visible absorption. NMR, MS, and EPR data are also reported. [on SciFinder(R)]