TY - JOUR
T1 - New Two-Photon Absorbing Squaraine Derivative with Efficient Near-Infrared Fluorescence, Superluminescence, and High Photostability
AU - Bondar, Mykhailo V.
AU - Faryadras, Sanaz
AU - Munera, Natalia
AU - Chang, Hao Jung
AU - Uddin, Mehrun
AU - Belfield, Kevin D.
AU - Kachkovsky, Olexiy D.
AU - Van Stryland, Eric W.
AU - Hagan, David J.
N1 - Funding Information:
M.V.B. wishes to thank the National Academy of Sciences of Ukraine (B/204). E.V.S., H.J.C., and D.J.H. thank the National Science Foundation grant DMR-1609895 for support. K.D.B. wishes to acknowledge support from the National Science Foundation (CBET-1517273 and CHE-1726345) and the National Institutes of Health (R21AA028340).
Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/6/2
Y1 - 2022/6/2
N2 - The nature of linear photophysical and nonlinear optical properties of a new squaraine derivative 2,4-bis[4-(azetidyl)-2-hydroxyphenyl]squaraine (1) with efficient near-infrared (NIR) emission was comprehensively analyzed based on spectroscopic, photochemical, and two-photon absorption (2PA) measurements, along with quantum chemical analysis. The steady-state absorption, fluorescence, and excitation anisotropy spectra of 1 and its fluorescence emission lifetimes revealed the multiple aspects of the electronic structure of 1, including the relative orientations of the main transition dipoles, effective rotational volumes in solvents of different polarities, and a maximum molar extinction of 1.35 × 10-5M-1·cm-1, which is unusually small for similar symmetric squaraines. The degenerate 2PA spectrum of 1 was obtained over a broad spectral range under femtosecond excitation, using standard open-aperture Z-scan and two-photon induced fluorescence methods, revealing maximum 2PA cross sections of ∼400 GM. Squaraine 1 exhibited efficient superluminescence emission in the polar solvent (dichloromethane) at room temperature under femtosecond pumping conditions. Quantum chemical analysis of the electronic structure of 1 was performed using the DFT/TD-DFT level of theory and found to be in good agreement with experimental data. The new squaraine derivative 1 displayed high fluorescence quantum yield, efficient NIR superluminescence, large 2PA cross sections, and high photostability with a photodecomposition quantum yield ∼4 × 10-6, suggesting its potential for applications in two-photon fluorescent bioimaging and lasing.
AB - The nature of linear photophysical and nonlinear optical properties of a new squaraine derivative 2,4-bis[4-(azetidyl)-2-hydroxyphenyl]squaraine (1) with efficient near-infrared (NIR) emission was comprehensively analyzed based on spectroscopic, photochemical, and two-photon absorption (2PA) measurements, along with quantum chemical analysis. The steady-state absorption, fluorescence, and excitation anisotropy spectra of 1 and its fluorescence emission lifetimes revealed the multiple aspects of the electronic structure of 1, including the relative orientations of the main transition dipoles, effective rotational volumes in solvents of different polarities, and a maximum molar extinction of 1.35 × 10-5M-1·cm-1, which is unusually small for similar symmetric squaraines. The degenerate 2PA spectrum of 1 was obtained over a broad spectral range under femtosecond excitation, using standard open-aperture Z-scan and two-photon induced fluorescence methods, revealing maximum 2PA cross sections of ∼400 GM. Squaraine 1 exhibited efficient superluminescence emission in the polar solvent (dichloromethane) at room temperature under femtosecond pumping conditions. Quantum chemical analysis of the electronic structure of 1 was performed using the DFT/TD-DFT level of theory and found to be in good agreement with experimental data. The new squaraine derivative 1 displayed high fluorescence quantum yield, efficient NIR superluminescence, large 2PA cross sections, and high photostability with a photodecomposition quantum yield ∼4 × 10-6, suggesting its potential for applications in two-photon fluorescent bioimaging and lasing.
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U2 - 10.1021/acs.jpcb.2c01288
DO - 10.1021/acs.jpcb.2c01288
M3 - Article
C2 - 35584210
AN - SCOPUS:85131267922
SN - 1520-6106
VL - 126
SP - 3897
EP - 3907
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 21
ER -