Stephen C. Wallace

Resonance energy transfer between lasing dyes in micellar media

Abstract The photophysical behaviour of rhodamine 6G and coumarin 1 has been studied in a range of aqueous micellar media. Resonance energy transfer is demonstrated in dilute (10 −5 M) solutions and the location of the dye molecules in the micelle deduced from fluorescence lifetimes. A highly efficient, energy transfer dye laser is reported for dyes in micellar matrices.

Picosecond dynamics of the S2 excited state of azulene and its van der Waals complexes with Ar and Xe

Abstract The dynamics of the second excited singlet (S 2 ) states of jet-cooled azulene (Az) and its van der Waals complexes with one and two atoms of Ar and Xe have been investigated. Quantum interference effects due to restricted intramolecular vibrational redistribution in azulene have been reinterpreted. Lifetime shortening in the 1:1 and 1:2 complexes with Xe is attributed to an enhancement of the rate of S 2 ue5f8T 1 intersystem crossing by the external heavy atom effect. Excitation of the complexes to states with E vib > E b produces energy-resolved fluorescence decays which exhibit sequential intramolecular vibrational redistribution-vibrational predissociation.