Superfluorescent Squaraine with Efficient Two-Photon Absorption and High Photostability
Abbreviated Journal Title
density functional calculations; donor-acceptor systems; fluorescence; hydrogen bonds; photochemistry; EXCITED-STATE ABSORPTION; NONLINEAR-OPTICAL PROPERTIES; SINGLET OXYGEN; GENERATION; ONE-PHOTON; MOLECULAR DESIGN; CROSS-SECTIONS; QUANTUM; YIELDS; DYES; DERIVATIVES; POLYMETHINE; Chemistry, Physical; Physics, Atomic, Molecular & Chemical
The synthesis, linear photophysical, two-photon absorption (2PA), femtosecond transient absorption, and superfluorescence properties of a new symmetrical squaraine derivative (1) are reported. Steady-state linear spectral and photochemical properties, fluorescence lifetimes, and excitation anisotropy of 1 were investigated in various organic solvents. High fluorescence quantum yields (approximate to 0.7) and very high photostability (photodecomposition quantum yields approximate to 10(-6)-10(-8)) were observed. An open-aperture Z-scan method was used to obtain 2PA spectra of 1 over a broad spectral range (maximum 2PA cross section approximate to 1000 GM). Excited-state absorption (ESA) and gain was observed by femtosecond transient absorption spectroscopy, in which both reached a maximum at approximately 500 fs. Squaraine 1 exhibits efficient superfluorescence. The quantum chemical study of 1 revealed the simulated vibronic nature of the 1PA and 2PA spectra were in good agreement with experimental data; this may provide the ability to predict potential advanced photonic materials.
"Superfluorescent Squaraine with Efficient Two-Photon Absorption and High Photostability" (2013). Faculty Bibliography 2010s. 3687.