scholarly journals Complexes trans-Pt(BODIPY)X(PEt3)2: excitation energy-dependent fluorescence and phosphorescence emissions, oxygen sensing and photocatalysis

2016 ◽  
Vol 45 (25) ◽  
pp. 10420-10434 ◽  
Author(s):  
Peter Irmler ◽  
Rainer F. Winter
Keyword(s):  
Excitation Energy ◽  
Oxygen Sensing ◽  
Single Component ◽  
Quantum Yields ◽  
Dual Fluorescence ◽  
Anionic Ligand ◽  
Energy Dependent ◽  
Fluorescence And Phosphorescence

Complexes trans-Pt(BODIPY)X(PEt3)2 exhibit dual fluorescence and phosphorescence emissions, whose intensities are modulated by the anionic ligand X− and the excitation wavelengths. They constitute efficient single-component 3O2 sensors and photocatalysts for aereal photooxidations with quantum yields near unity.

scholarly journals Difluoroboron β-diketonate polylactic acid oxygen nanosensors for intracellular neuronal imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meng Zhuang ◽  
Suchitra Joshi ◽  
Huayu Sun ◽  
Tamal Batabyal ◽  
Cassandra L. Fraser ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Oxygen Sensing ◽  
Brain Slices ◽  
Neuronal Cell ◽  
Quantum Yields ◽  
Poly Lactic Acid ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures ◽  
Non Invasive ◽  
Mitotracker Red

AbstractCritical for metabolism, oxygen plays an essential role in maintaining the structure and function of neurons. Oxygen sensing is important in common neurological disorders such as strokes, seizures, or neonatal hypoxic–ischemic injuries, which result from an imbalance between metabolic demand and oxygen supply. Phosphorescence quenching by oxygen provides a non-invasive optical method to measure oxygen levels within cells and tissues. Difluoroboron β-diketonates are a family of luminophores with high quantum yields and tunable fluorescence and phosphorescence when embedded in certain rigid matrices such as poly (lactic acid) (PLA). Boron nanoparticles (BNPs) can be fabricated from dye-PLA materials for oxygen mapping in a variety of biological milieu. These dual-emissive nanoparticles have oxygen-insensitive fluorescence, oxygen-sensitive phosphorescence, and rigid matrix all in one, enabling real-time ratiometric oxygen sensing at micron-level spatial and millisecond-level temporal resolution. In this study, BNPs are applied in mouse brain slices to investigate oxygen distributions and neuronal activity. The optical properties and physical stability of BNPs in a biologically relevant buffer were stable. Primary neuronal cultures were labeled by BNPs and the mitochondria membrane probe MitoTracker Red FM. BNPs were taken up by neuronal cell bodies, at dendrites, and at synapses, and the localization of BNPs was consistent with that of MitoTracker Red FM. The brain slices were stained with the BNPs, and the BNPs did not significantly affect the electrophysiological properties of neurons. Oxygen maps were generated in living brain slices where oxygen is found to be mostly consumed by mitochondria near synapses. Finally, the BNPs exhibited excellent response when the conditions varied from normoxic to hypoxic and when the neuronal activity was increased by increasing K+ concentration. This work demonstrates the capability of BNPs as a non-invasive tool in oxygen sensing and could provide fundamental insight into neuronal mechanisms and excitability research.

scholarly journals Ultrafast charge transfer dynamics in 2D Covalent Organic Frameworks/Re-complex hybrid photocatalyst for CO2 reduction: hot electrons vs. cold electrons

2021 ◽  
Author(s):  
Qinying Pan ◽  
Mohamed Abdellah ◽  
Yuehan Cao ◽  
Yang Liu ◽  
Weihua Lin ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Excitation Energy ◽  
Co2 Reduction ◽  
Underlying Mechanism ◽  
High Energy ◽  
Hot Electrons ◽  
Covalent Organic Frameworks ◽  
Energy Excitation ◽  
Energy Dependent

Abstract Rhenium(I)-carbonyl-diimine complexes are promising photocatalysts for CO2 reduction. Covalent organic frameworks (COFs) can be perfect sensitizers to enhance the reduction activities. Here we investigated the excited state dynamics of COF (TpBpy) with 2,2'-bipyridine incorporating Re(CO)5Cl (Re-TpBpy) to rationalize the underlying mechanism. The time-dependent DFT calculation first clarified excited state structure of the hybrid catalyst. The studies from transient visible and infrared spectroscopies revealed the excitation energy-dependent photo-induced charge transfer pathways in Re-TpBpy. Under low energy excitation, the electrons at the LUMO level are quickly injected from Bpy into ReI center (1–2 ps) followed by backward recombination (13 ps). Under high energy excitation, the hot-electrons are first injected into the higher unoccupied level of ReI center (1–2 ps) and then slowly relax back to the HOMO in COF (24 ps). There also remains long-lived free electrons in the COF moiety. This explained the excitation energy-dependent CO2 reduction performance in our system.

Ultrafast excited state dynamics of fucoxanthin: excitation energy dependent intramolecular charge transfer dynamics

2011 ◽  
Vol 13 (22) ◽  
pp. 10762 ◽  
Author(s):  
Daisuke Kosumi ◽  
Toshiyuki Kusumoto ◽  
Ritsuko Fujii ◽  
Mitsuru Sugisaki ◽  
Yoshiro Iinuma ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Excitation Energy ◽  
Intramolecular Charge Transfer ◽  
Excited State Dynamics ◽  
Charge Transfer Dynamics ◽  
Energy Dependent

Excitation Energy Dependent Charge Separation at Hole-Transporting Dye/TiO2 Hetero Interface

2012 ◽  
Vol 116 (40) ◽  
pp. 21148-21156 ◽  
Author(s):  
Eva L. Unger ◽  
Tomas Edvinsson ◽  
Joseph D. Roy-Mayhew ◽  
Håkan Rensmo ◽  
Anders Hagfeldt ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Charge Separation ◽  
Hole Transporting ◽  
Energy Dependent

Trifluoromethyl-substituted cyclometalated iridiumIII emitters with high photostability for continuous oxygen sensing

2015 ◽  
Vol 3 (31) ◽  
pp. 8010-8017 ◽  
Author(s):  
Chun Liu ◽  
Xin Lv ◽  
Yang Xing ◽  
Jieshan Qiu
Keyword(s):  
Oxygen Sensing ◽  
High Sensitivity ◽  
Quantum Yields ◽  
Quick Response ◽  
Oxidation Potentials ◽  
Enhanced Photostability ◽  
Oxygen Concentrations

New trifluoromethyl-substituted cyclometalated Ir(iii) complexes exhibit high photoluminescence quantum yields, increased oxidation potentials and enhanced photostability. The oxygen sensing films immobilized with Ir(iii) complexes demonstrate quick response and high sensitivity upon changes of oxygen concentrations.

Excitation energy dependent switchable emission in SrZnO2 nanophosphors: XAS and luminescence studies

2020 ◽  
Vol 8 (9) ◽  
pp. 3147-3155 ◽  
Author(s):  
Manju ◽  
Megha Jain ◽  
Pargam Vashishtha ◽  
Sanjay Kumar ◽  
Parasmani Rajput ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Dual Emission ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Energy Dependent

An unprecedented excitation energy dependent dual emission from SrZnO2 nanophosphors is observed, predicting its applicability for switchable light emitting devices.

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