Fluorescence lifetimes of rhodamine dyes in vacuo

摘要: Abstract Laser-induced fluorescence lifetimes are reported for several mass-selected gas-phase rhodamine cations, which were generated using electrospray ionization. A recently developed instrument consisting of a quadruple ion trap mass spectrometer coupled to tunable laser excitation source is used storage and irradiation, respectively. Time-resolved measurements carried out time-correlated single photon counting (TCSPC), with Single Photon Avalanche Diode (SPAD) efficient detection the light. The time-resolved data well fit exponential decays. Measured 5.65 ± 0.04 ns gaseous cationic 575 (also known as 19), 5.83 ± 0.06 ns 590, 5.87 ± 0.05 ns 6G 6.92 ± 0.06 ns 640 101). These values first reports 575, 590 6G, while uncertainty lifetime an order magnitude smaller than previously value. these rhodamines all longer their measured in solution. Photo-physical processes leading increase molecules gas phase compared solution behavior discussed. Knowledge intrinsic rhodamines, provided this work, will aid development resonance energy transfer structural probe ions. It also form basis from better understand how interactions solvent influence properties fluorescent dyes.