1,3-Diphenylpropenylium (DP3(+)) and 1,5-diphenylpentadienylium (DP5(+)) ions have been generated within acid ZSM-5 and mordenite zeolites as persistent species by adsorption of alpha,omega-disubstituted alpha,omega-diphenylalkanes. It was found that besides alpha,omega-diacetates, alpha,omega-dichlorides and alpha,omega-diols are also convenient precursors, Irradiation of these allylic cations embedded within zeolites led to cis-trans isomerization as the only observable process. Molecular modeling suggests that there is enough space in the intersection of the channels in HZSM-5 to accommodate both the planar E,E-DP3(+) and the nonplanar E,Z-DP3(+) stereoisomers. Fluorescence emissions follow a near-first-order decay, with a dominant short and a minor long component; the latter having a lifetime close to that reported for DP5(+) in solution at low temperatures. Z-E isomerization led to a blue-shift in the absorption spectra together with an increase in the apparent extinction coefficient, while emission maxima also appeared at longer wavelengths exhibiting distinctive decays. Evidence for the tripler excited states has been obtained by time-resolved diffuse reflectance spectroscopy. Estimated lifetimes obtained from the best first-order fit are in the tens of microseconds range. Weak delayed emission associated to the triplet excited state has also been observed.