Induced phosphorescence of some aza- and thio-stilbenes embedded in thallium-exchanged zeolites

► The exchange of Na+ with heavy Tl+ cations in faujasite zeolites allowed the triplet properties of some hetero-stilbenes to be obtained. ► The absorption and fluorescence spectra in NaY and TlY were measured and compared with those in fluid solutions. ► The triplet energy levels and lifetimes of three aza-stilbenes and three thio-stilbenes in TlY were determined by measuring their phosphorescence emission at liquid nitrogen temperature.