scholarly journals Tunable benzothiadiazole-based donor–acceptor materials for two-photon excited fluorescence

2020 ◽  
Vol 4 (2) ◽  
pp. 555-566 ◽  
Author(s):  
Nathan R. Paisley ◽  
Christopher M. Tonge ◽  
Don M. Mayder ◽  
Kyle A. Thompson ◽  
Zachary M. Hudson

Spectrally tunable, two-photon active benzothiadiazole-based fluorescent materials are realized by a simple synthetic strategy. Deep red emission from two-photon absorption, and incorporation into water-soluble polymer dots are achieved.

2016 ◽  
Vol 7 (7) ◽  
pp. 4527-4536 ◽  
Author(s):  
Zheng-Feng Chang ◽  
Ling-Min Jing ◽  
Bin Chen ◽  
Mengshi Zhang ◽  
Xiaolei Cai ◽  
...  

Donor–acceptor π-conjugated aggregation-induced red emission materials for live cell imaging.


2019 ◽  
Author(s):  
Pralok K. Samanta ◽  
Md Mehboob Alam ◽  
Ramprasad Misra ◽  
Swapan K. Pati

Solvents play an important role in shaping the intramolecular charge transfer (ICT) properties of π-conjugated molecules, which in turn can affect their one-photon absorption (OPA) and two-photon absorption (TPA) as well as the static (hyper)polarizabilities. Here, we study the effect of solvent and donor-acceptor arrangement on linear and nonlinear optical (NLO) response properties of two novel ICT-based fluorescent sensors, one consisting of hemicyanine and dimethylaniline as electron withdrawing and donating groups (molecule 1), respectively and its boron-dipyrromethene (BODIPY, molecule 2)-fused counterpart (molecule 3). Density functional theoretical (DFT) calculations using long-range corrected CAM-B3LYP and M06-2X functionals, suitable for studying properties of ICT molecules, are employed to calculate the desired properties. The dipole moment (µ) as well as the total first hyperpolarizability (β<sub>total</sub>) of the studied molecules in the gas phase is dominantly dictated by the component in the direction of charge transfer. The ratios of vector component of first hyperpolarizability (β<sub>vec</sub>) to β<sub>total</sub> also reveal unidirectional charge transfer process. The properties of the medium significantly affect the OPA, hyperpolarizability and TPA properties of the studied molecules. Time dependent DFT (TDDFT) calculations suggest interchanging between two lowest excited states of molecule 3 from the gas phase to salvation. The direction of charge polarization and dominant transitions among molecular orbitals involved in the OPA and TPA processes are studied. The results presented are expected to be useful in tuning the NLO response of many ICT-based chromophores, especially those with BODIPY acceptors.<br>


2007 ◽  
Vol 11 (06) ◽  
pp. 406-417 ◽  
Author(s):  
Yusuke Inaba ◽  
Kazuya Ogawa ◽  
Yoshiaki Kobuke

Acetylene-bridged bisporphyrins and trisporphyrins having branched bulky bis(carboxylethyl)methyl meso-substituents were synthesized. These compounds showed large effective two-photon absorption cross-section values at 890 nm measured by using a nanosecond Z-scan method. Sodium salt of hydrolyzed trisporphyrins showed broad and red-shifted Q-bands over 900 nm. Two-photon absorption cross-section values of water-soluble dimers in water were similar to, or slightly larger than, those of ester forms evaluated in toluene. Furthermore, the generation of singlet oxygen upon one-photon irradiation for dimers in water was confirmed.


Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 715
Author(s):  
Katarzyna C. Nawrot ◽  
Dominika Wawrzyńczyk ◽  
Oleksii Bezkrovnyi ◽  
Leszek Kępiński ◽  
Bartłomiej Cichy ◽  
...  

We demonstrate a low-temperature synthesis of hydrophilic, penicillamine-stabilized hybrid CdS-Au nanoparticles (NPs) utilizing different Au concentrations. The obtained hybrid nanomaterials exhibit photoluminescence quenching and emission lifetime reduction in comparison with their raw semiconductor CdS NPs counterparts. An increase of concentration of Au present at the surface of CdS leads to lower photoluminescence intensity and faster emission decays, suggesting more efficient charge separation when larger Au domains are present. For photocatalysis studies, we performed methylene blue (MB) absorption measurements under irradiation in the presence of CdS-Au NPs. After 1 h of light exposure, we observed the absorbance decrease to about 35% and 10% of the initial value for the CdS-5Au and CdS-7.5Au (the hybrid NPs obtained in a presence of 5.0 and 7.5 mM Au), respectively, which indicates MB reduction caused by electrons effectively separated from holes on metal surface. In further similar photocatalysis experiments, we measured bovine serum albumin (BSA) integrated photoluminescence intensity quenching in the presence of CdS-Au NPs, with a 50% decrease being obtained for CdS-2.5Au NPs and CdS-5Au NPs, with a faster response rate detected for the system prepared with a higher Au concentration. The results suggest hole-driven reactive oxygen species (ROS) production, causing BSA degeneration. Finally, we performed two-photon excited emission (TPEE) measurements for CdS-5Au NPs, obtaining their two-photon absorption (TPA) cross-section values up to 15.8 × 103 GM (Goeppert-Mayer units). We conclude that the obtained water-soluble CdS-Au NPs exhibit potential triple functionalities as photocatalysts for reduction and oxidation reactions as well as materials for two-photon absorption applications, so that they may be considered as future theranostics.


2020 ◽  
Vol 124 (45) ◽  
pp. 24631-24643
Author(s):  
Yogajivan Rout ◽  
Alessio Cesaretti ◽  
Elena Ferraguzzi ◽  
Benedetta Carlotti ◽  
Rajneesh Misra

2017 ◽  
Vol 5 (7) ◽  
pp. 1724-1729 ◽  
Author(s):  
D. Wawrzyńczyk

Synthesized penicillamine stabilized CdS tetrapods showed two-photon absorption in a wavelength range between 600 and 850 nm, and strong two-photon excited emission upon near infrared excitation. These water soluble colloidal, semiconducting nanoparticles show potential for applications in nonlinear bioimaging.


2015 ◽  
Vol 3 (4) ◽  
pp. 742-749 ◽  
Author(s):  
Anna Purc ◽  
Krzysztof Sobczyk ◽  
Yusuke Sakagami ◽  
Akihiro Ando ◽  
Kenji Kamada ◽  
...  

Decorating diketopyrrolopyrroles with strongly electron-rich heterocycles led to donor–acceptor–donor architectures possessing two-photon brightness 850–1900 GM.


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