Guest-boosted phosphorescence efficiency of a supramolecular cage

2021 ◽  
Author(s):  
Zhi-Yin Zhang ◽  
Dong-Qin Ye ◽  
Qi-Qi Gao ◽  
Zhi-Chun Shi ◽  
Mo Xie ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Inclusion Complexes ◽  
Emission Lifetime

The quantum yield and emission lifetime of the inclusion complexes can be fine-tuned via the variation of halobenzene guests.

Measurement of Emission Lifetime Dynamics and Biexciton Emission Quantum Yield of Individual InAs Colloidal Nanocrystals

Nano Letters ◽  
2014 ◽  
Vol 14 (12) ◽  
pp. 6787-6791 ◽  
Author(s):  
Thomas S. Bischof ◽  
Raoul E. Correa ◽  
Danna Rosenberg ◽  
Eric A. Dauler ◽  
Moungi G. Bawendi
Keyword(s):  
Quantum Yield ◽  
Colloidal Nanocrystals ◽  
Emission Lifetime ◽  
Emission Quantum Yield

Light Emission Properties and Biological Applications of Lanthanide Doped Oxide Nanoparticles

2007 ◽  
Vol 1064 ◽  
Author(s):  
Genevieve Mialon ◽  
Domitille Giaume ◽  
Melanie Moreau ◽  
Didier Casanova ◽  
Thanh-Liem Nguyen ◽  
...  
Keyword(s):  
Rare Earth ◽  
Quantum Yield ◽  
Bulk Material ◽  
General Scheme ◽  
Hydroxyl Groups ◽  
Emission Properties ◽  
Biological Probes ◽  
Emission Lifetime ◽  
Rare Earth Doped ◽  
Doped Oxide

ABSTRACTRare-earth doped oxides as bulk materials are well known for their numerous applications in light emitting devices. Emission properties of nanoparticles, in association with their small size, open the way to new applications such as the elaboration of transparent luminescent devices or new biological labels. The key issue for such applications is the control of the surface state of the particles in order to preserve their dispersion state, to guarantee a strong emission and/or ensure strong interactions with specific target sites. Our work in this field mainly concerns yttrium vanadate particles (YVO4:Ln with Ln=Eu, Dy and Yb/Er) that are obtained as aqueous suspensions through a simple reaction of coprecipitation [1]. As compared to the bulk material, these particles (10-40 nm in diameter) exhibit the characteristic emission from the lanthanide dopant but with a lower efficiency (quantum yield of 15% and emission lifetime of 0.7 ms). The first part of our work is devoted to the improvement of the emission properties of particles. Our results show that the emission process is altered either by surface hydroxyl groups or by the poor cristallinity of the particles. We show that large improvement can be obtained following an original process which allows recovering the particles as colloidal dispersions after their thermal treatment at 1000°C. In the case of Eu3+ doped particles, quantum yield and emission lifetime were increased up to 40% and 0.8 ms respectively without notable increase of particle size. Moreover, the emission spectrum, either from colloidal suspensions or from single particles fits almost perfectly to the one from the bulk material. The second part of our work is devoted to the surface derivatization of the particles for applications as biological probes [2]. We chose a general scheme involving the coating of the nanoparticles with a thin layer of amino-silane. This process was chosen in order to allow further versatile grafting reactions trough the surface amino groups. This strategy will be detailed in the case of the coupling between our particles and a protein through the use of a homo-bifunctional cross-linker. The quantification of the number of attached proteins was achieved using dual-color microscopy and fluorescently-tagged proteins, by observing the step-like photobleaching of the organic fluorescent tag. The observation of labelled toxins interacting with living cells shows the high potentiality of rare-earth-doped oxide particles as new biological probes.

scholarly journals The Solid-State Emission of Bilirubin

2020 ◽  
Author(s):  
Ahmed El-Zohry ◽  
Taha Ahmed ◽  
Burkhard Zietz
Keyword(s):  
Solid State ◽  
Quantum Yield ◽  
Room Temperature ◽  
Crystal Quality ◽  
Biological Sensors ◽  
Frenkel Exciton ◽  
Aggregation Induced Emission ◽  
Isomerization Process ◽  
Emission Lifetime

<p>Bilirubin (BR) is a human-biological compound formed during the haem metabolism that is insoluble in most solvents. BR has shown short emission lifetime with low quantum yield in limited number of solvents, due to the non-radiative ultrafast isomerization process. However, in solid-state, red-shifted emission of long-lived species of BR are detected at room temperature, due to the aggregation-induced emission formed by Frenkel exciton of J-system. This solid-state emission of BR depends on the crystal quality of BR as shown by SEM and XRD. This study allows for better understandings of the photophysics of BR in solid-state, opening opportunities for its applications in luminescent biological sensors. </p>

Novel Cyclometalated Iridium(III) Xanthate Complexes and Their Phosphorescence Behavior in the Presence of Metal Ions

2012 ◽  
Vol 67 (9) ◽  
pp. 865-871
Author(s):  
Bihai Tong ◽  
Yaqing Xu ◽  
Jiayan Qiang ◽  
Man Zhang ◽  
Qunbo Mei ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Metal Ions ◽  
Single Crystal ◽  
Photophysical Properties ◽  
Metal Cations ◽  
X Ray Diffraction ◽  
Red Emission ◽  
X Ray ◽  
Emission Lifetime ◽  
Phosphorescence Quantum Yield

Two cyclometalated iridium(III) complexes, Ir(dpppz)(ppz)(ipx) and Ir(ppz)2(ipx) (dpppzH=1- (2,6-dimethylphenoxy)-4-phenylphthalazine, ppzH=4-phenylphthalazinone, ipx=isopropyl xanthate), have been synthesized and characterized by single-crystal X-ray diffraction. The photophysical properties of the two complexes were also investigated. Ir(dpppz)(ppz)(ipx) shows orange-red emission at around 606 nm with a phosphorescence quantum yield of ca. 0.0032 and an emission lifetime of 188 ns, while Ir(ppz)2(ipx) shows orange-red emission at around 599 nm with a phosphorescence quantum yield of ca. 0.00318 and an emission lifetime of 259 ns. The phosphorescence behavior of Ir(ppz)2(ipx) towards different metal cations has also be studied. Its strong phosphorescence is quenched by Hg2+, Cu2+ and Ag+ cations. The interaction ratio with Hg2+ is 1:1

Solvent effect on the emission lifetime and its quantum yield of [(MoII6Cl8)Cl6]2−

1989 ◽  
Vol 161 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Hideaki K. Tanaka ◽  
Yoichi Sasaki ◽  
Masahiro Ebihara ◽  
Kazuo Saito
Keyword(s):  
Quantum Yield ◽  
Solvent Effect ◽  
Emission Lifetime

scholarly journals Rigid biimidazole ancillary ligands as an avenue to bright deep blue cationic iridium(iii) complexes

2014 ◽  
Vol 174 ◽  
pp. 165-182 ◽  
Author(s):  
Adam F. Henwood ◽  
Sloane Evariste ◽  
Alexandra M. Z. Slawin ◽  
Eli Zysman-Colman
Keyword(s):  
Quantum Yield ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Iridium Complexes ◽  
Functional Theory ◽  
Ancillary Ligands ◽  
Deep Blue ◽  
Pyridine Complex ◽  
Emission Lifetime ◽  
Very High

Herein we report the synthesis and optoelectronic characterisation of three deep blue-emitting cationic iridium complexes, of the form [Ir(dFppy)2(N^N)]PF6, bearing biimidazole-type N^N ancillary ligands (dFppyH = 2-(2,4-difluorophenyl)pyridine). Complex 1 contains the parent biimidazole, biim, while 2 contains a dimethylated analog, dMebiim, and 3 contains an ortho-xylyl-tethered biimidzole, o-xylbiim. We explore a strategy of tethering the biimidazole in order to rigidify the complex and increase the photoluminescent quantum yield, culminating in deep blue (λmax: 457 nm in MeOH at 298 K) ligand-centered emission with a very high photoluminescent quantum yield of 68% and microsecond emission lifetime. Density functional theory calculations elucidate the origin of such disparate excited state kinetics across this series, especially in light of virtually identical optoelectronic properties observed for these compounds.

Influence of cyclodextrins on the fluorescence, photostability and singlet oxygen quantum yields of zinc phthalocyanine and naphthalocyanine complexes

2003 ◽  
Vol 07 (06) ◽  
pp. 439-446 ◽  
Author(s):  
Prudence Tau ◽  
Abimbola O. Ogunsipe ◽  
Suzanne Maree ◽  
M. David Maree ◽  
Tebello Nyokong
Keyword(s):  
Quantum Yield ◽  
Singlet Oxygen ◽  
Inclusion Complexes ◽  
Photophysical Properties ◽  
Zinc Phthalocyanine ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Cyclodextrin Inclusion Complexes ◽  
Cyclodextrin Inclusion ◽  
Zinc Phthalocyanines

The effects of formation of cyclodextrin inclusion complexes on the photochemical and photophysical properties of zinc phthalocyanine ( ZnPc ) and various peripherally substituted zinc phthalocyanines as well as zinc naphthalocyanine ( ZnNPc ) are investigated. The cyclodextrins employed were the hydroxypropyl-γ-cyclodextrin and unsubstituted β-cyclodextrin. Job's plots were employed to confirm the stoichiometry of the inclusion complexes and showed 2:1 and 4:1 (cyclodextrin:phthalocyanine) inclusion behavior. The phthalocyanine inclusion complexes showed larger singlet oxygen quantum yield (ϕΔ) values when compared to the free phthalocyanines before inclusion, for complexes 1 (zinc naphthalocyanine), 2 (zinc tetranitrophthalocyanine) and 4 (zinc tetra-tert-butylphenoxyphthalocyanine). The fluorescence quantum yields generally remained unchanged following inclusion.

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