Department of Chemistry, University of Central Florida, P.O. Box 162366, Orlando, FL 32816-2366 (USA); CREOL, The College of Optics and Photonics, University of Central Florida, P.O. Box 162366, Orlando, FL 32816-2366 (USA).
Chemphyschem. 2013 Oct 21;14(15):3532-42. doi: 10.1002/cphc.201300447. Epub 2013 Sep 10.
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 (≈0.7) and very high photostability (photodecomposition quantum yields ≈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 ≈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.
报告了一种新的对称方酸衍生物（1）的合成、线性光物理、双光子吸收（2PA）、飞秒瞬态吸收和超荧光性质。在各种有机溶剂中研究了 1 的稳态线性光谱和光化学性质、荧光寿命和激发各向异性。观察到高荧光量子产率（≈0.7）和非常高的光稳定性（光分解量子产率≈10（-6）-10（-8））。采用开孔径 Z 扫描法在较宽的光谱范围内获得了 1 的 2PA 光谱（最大 2PA 截面≈1000 GM）。通过飞秒瞬态吸收光谱观察到激发态吸收（ESA）和增益，在大约 500 fs 时达到最大值。方酸 1 表现出有效的超荧光。1 的量子化学研究揭示了 1PA 和 2PA 光谱的模拟振子性质与实验数据吻合良好；这可能提供预测潜在先进光子材料的能力。
