An unusual way to luminescent terbium molecular-level hybrid materials: Modified methyl benzoic acid covalently bonded with silica as a bridge

2005 ◽  
Vol 20 (3) ◽  
pp. 592-598 ◽  
Author(s):  
Qianming Wang ◽  
Bing Yan
Keyword(s):  
Benzoic Acid ◽  
Hybrid Material ◽  
Photophysical Properties ◽  
Green Emission ◽  
Energy Difference ◽  
Luminescence Spectra ◽  
Triplet Energy ◽  
Covalent Bonds ◽  
Organic Part ◽  
Covalently Bonded

The syntheses of modified ortho or meta methylbenzoic acid by (3-aminopropyl)triethoxysilane and the preparation of their corresponding organic–inorganic molecular-based hybrid material with the two components equipped with covalent bonds are described. The organic part is a derivative of methyl benzoic acid, which is used to coordinate to Tb3+ and further introduced into silica matrices by Si–O bonds after hydrolysis and polycondensation processes. The Judd–Ofelt theory proves that covalency increases along with increasing reciprocal energy difference between the 4fN and 4fN−15d1 configurations. Ultraviolet absorption, phosphorescence spectra, and luminescence spectra were applied to characterize the photophysical properties of the obtained hybrid material, and the above spectroscopic data reveal that the triplet energy of modified methyl benzoic acid matches with the emissive energy level of Tb3+. In this way, the intramolecular energy transfer process took place within these molecular-based hybrids, and strong green emission of Tb3+ was obtained.

Optical Limiting of a Covalently Bonded Gold Nanoparticle/Polylysine Hybrid Material

2005 ◽  
Vol 109 (44) ◽  
pp. 20854-20857 ◽  
Author(s):  
Wenfang Sun ◽  
Qiu Dai ◽  
James G. Worden ◽  
Qun Huo
Keyword(s):  
Gold Nanoparticle ◽  
Hybrid Material ◽  
Optical Limiting ◽  
Covalently Bonded

Tuning the Photophysical Properties of Cyclometalated Ir(III) Complexes by a Trifluoroacetyl Group

2012 ◽  
Vol 67 (3) ◽  
pp. 213-218 ◽  
Author(s):  
Bihai Tong ◽  
Jiayan Qiang ◽  
Qunbo Mei ◽  
Hengshan Wang ◽  
Qianfeng Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Electron Acceptor ◽  
Photophysical Properties ◽  
Red Shift ◽  
Luminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Absorption And Luminescence Spectra ◽  
Homo Lumo

Four cationic Ir(III) complexes, [Ir(dpq)2(bpy)]PF6 (1), [Ir(dpq)2(phen)]PF6 (2), [Ir(tfapq)2- (bpy)]PF6 (3), and [Ir(tfapq)2(phen)]PF6 (4) (dpqH = 2,4-diphenylquinoline, tfapqH = 2-(4ʹ-trifluoroacetylphenyl)- 4-phenylquinoline, bpy = 2,2ʹ-bipyridine, phen = 1,10-phenanthroline) have been synthesized and fully characterized. The structure of 4 was also confirmed by single-crystal X-ray diffraction. The electron-acceptor character of the trifluoroacetyl unit leads to a reduced HOMO-LUMO gap and consequently a red-shift of the UV/Vis absorption and luminescence spectra. The solvophobic character of the trifluoroacetyl unit gives rise to a molecule assembly in solution.

scholarly journals Fabrication of Photofunctional Nanoporous Membrane and Its Photoinactivation Effect of Vesicular Stomatitis Virus

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Kang-Kyun Wang ◽  
Bong-Jin Kim ◽  
Si-Hwan Ko ◽  
Dong Hoon Choi ◽  
Yong-Rok Kim
Keyword(s):  
Vesicular Stomatitis Virus ◽  
Photophysical Properties ◽  
Antiviral Effect ◽  
Nanosecond Laser ◽  
Alumina Membrane ◽  
Time Resolved ◽  
Nanoporous Alumina ◽  
Animal Virus ◽  
Covalently Bonded ◽  
Vesicular Stomatitis

Fabrication and photophysical study of photofunctional nanoporous alumina membrane (PNAM) were performed, and its application of photodynamic antimicrobial chemotherapy (PACT) was investigated. Nanoporous alumina membrane (NAM) was fabricated by two-step aluminium anodic oxidation process. Surface of the fabricated NAM was modified with organo-silane agent to induce covalent bonding between NAM and a photosensitizer (PtCP: [5,10,15-triphenyl-20-(4-methoxycarbonylphenyl)-porphyrin] platinum). PtCP was covalently bonded to the surface of the modified NAM by nucleophilic acyl substitution reaction process. The morphology and the photophysical properties of the fabricated PNAM were confirmed with field emission scanning electron microscope (FE-SEM), steady-state spectroscopies, and nanosecond laser-induced time-resolved spectroscopy. For the efficacy study of PNAM in PACT, an enveloped animal virus, vesicular stomatitis virus (VSV), was utilized as a target organism. Antiviral effect of the PNAM-PACT was measured by the extent of suppression of plaque-forming units (PFU) after the light irradiation. In the cultures inoculated with PACT-treated VSV, the suppression of PFU was prominent, which demonstrates that PNAM is a potential bio clean-up tool.

scholarly journals The Temperature Dependence of Fundamental Photophysical Properties of [Eu(MeOH-d4)9]3+ Solvates and [Eu.DOTA(MeOH-d4)]- Complexes

2021 ◽  
Author(s):  
Nicolaj Kofod ◽  
Lea Gundorff Nielsen ◽  
Thomas Just Sørensen
Keyword(s):  
Transition Probabilities ◽  
Photophysical Properties ◽  
Transition Probability ◽  
Energy Levels ◽  
Emission Spectra ◽  
Lanthanide Ions ◽  
Quantum Yields ◽  
Luminescence Spectra ◽  
Absorption Cross ◽  
Apparent Lack

The trivalent lanthanide ions show optical transitions between energy levels within the 4f shell. All these transitions are formally forbidden according to the quantum mechanical selection rules used in molecular photophysics. Nevertheless, highly luminescent complexes can be achieved, and terbium(iii) and europium(iii) ions are particularly efficient emitters. This report started when an apparent lack of data in the literature led us to revisit the fundamental photophysics of europium(iii). The photophysical properties of two complexes – [Eu.DOTA(MeOH-d4)]- and [Eu(MeOH-d4)9]3+ – were investigated in deuterated methanol at five different temperatures. Absorption spectra showed decreased absorption cross sections as the temperature was increased. Luminescence spectra and time-resolved emission decay profiles showed a decrease in intensity and lifetime as a temperature was increased. Having corrected the emission spectra for the actual number of absorbed photons and differences in non-radiative pathways, the relative emission probability was revealed. These were found to increase with increasing temperature. The transition probability for luminescence was shown to increase with temperature, while the transition probability for light absorption decreased. The changes in transition probabilities were correlated to a change in the symmetry of the absorber or emitter, with an average increase in symmetry lowering absorption cross section and access to more asymmetric structures increasing the emission rate constant. Determining luminescence quantum yields and the Einstein coefficient for spontaneous emission allowed us to conclude that lowering symmetry increases both. Further, it was found that collisional self-quenching is an issue for lanthanide luminescence, when high concentrations are used. Finally, detailed analysis revealed results that show the so-called ‘Werts’ method’ for calculating radiative lifetimes and intrinsic quantum yields are based on assumption that does not hold for the two systems investigated here. We conclude that we are lacking a good theoretical description of the intraconfigurational f-f transition, and that there are still aspects of fundamental lanthanide photophysics to be explored.<br>

Highly emissive MAPbBr3 perovskite QDs by ligand-assisted reprecipitation: the antisolvent effect

2021 ◽  
Author(s):  
Wallison Costa ◽  
Cristian Salla ◽  
Fernando Ely ◽  
Ivan Bechtold
Keyword(s):  
Reaction Time ◽  
Photophysical Properties ◽  
Green Emission ◽  
Precipitation Method ◽  
Uv Curable ◽  
Hybrid Perovskite ◽  
Absolute Quantum Yield ◽  
Synthetic Procedure ◽  
Solid Film ◽  
Down Conversion

Abstract A systematic study of the synthetic procedure to improve quantum efficiency of luminescent hybrid perovskite QDs through ligand-assisted precipitation method is presented. Particularly, the influence of the dielectric constant and dipole moment of the antisolvent on the reaction time and the photophysical properties of the QDs is highlighted. After evaluating the influence of antisolvents and optimizing experimental parameters such as reaction time and Pb excess of the precursor, colloidal crystalline MAPbBr3 QDs with exceptionally high absolute quantum yield up to 97.7% in solution and 69.1% in solid film were obtained. Finally, MAPbBr3 QDs precipitated from anisole were processed like UV-curable nanocomposite as efficient down conversion layer resulting in very narrow green emission LED.

A New Fluoride Luminescence Quencher Based on a Nanostructured Covalently Bonded Terbium Hybrid Material

2010 ◽  
Vol 114 (32) ◽  
pp. 13879-13883 ◽  
Author(s):  
Qianming Wang ◽  
Chaoliang Tan ◽  
Hongyu Chen ◽  
Hitoshi Tamiaki
Keyword(s):  
Hybrid Material ◽  
Covalently Bonded

scholarly journals Aqueous Photon Upconversion by Anionic Acceptors Self-Assembled on Cationic Bilayer Membranes with a Long Triplet Lifetime

2019 ◽  
Vol 01 (01) ◽  
pp. 043-049
Author(s):  
Deepak Asthana ◽  
Shota Hisamitsu ◽  
Masa-aki Morikawa ◽  
Pengfei Duan ◽  
Takuya Nakashima ◽  
...  
Keyword(s):  
Self Assembly ◽  
Molecular Design ◽  
Luminescence Spectra ◽  
Scanning Calorimetry ◽  
Triplet Energy ◽  
Bilayer Membranes ◽  
Excitation Light ◽  
Hydrogen Bond Networks ◽  
Inner Surface ◽  
Triplet Lifetime

Anionic 9,10-diphenylanthracene chromophores electrostatically bound to cationic, chiral bilayer membranes show ordered self-assembly in water. The integrity of the chromophore-accumulated aqueous bilayer membranes is ensured by multiple hydrogen-bond networks introduced in the bilayer, which allowed adaptive accommodation of the guest chromophores at the inner surface of the bilayer while maintaining their cohesive interactions. The regular chromophore alignment in the aqueous assembly is confirmed by differential scanning calorimetry, circular dichroism, and circularly polarized luminescence spectra. Excitonic migration of triplet energy occurs among the chromophores densely organized at the inner surface of the bilayer, which lead to triplet–triplet annihilation-based photon upconversion (TTA-UC). This acceptor-bilayer self-assemblies show a notably long triplet lifetime of 8.0 ms, which allows TTA-UC at sufficiently low excitation light intensity. These results demonstrate the usefulness of the simple electrostatic accumulation approach for TTA-UC chromophores where the suitable molecular design of the TTA-UC chromophore-integrated bilayer membranes plays a key role.

Sign in / Sign up

Export Citation Format

Share Document