| 1. |
- Ding, Aixiang, et al.
(författare)
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Complex-Formation-Enhanced Fluorescence Quenching Effect for Efficient Detection of Picric Acid
- 2014
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Ingår i: Chemistry - A European Journal. - : Wiley-VCH Verlag. - 0947-6539 .- 1521-3765. ; 20:38, s. 12215-12222
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Tidskriftsartikel (refereegranskat)abstract
- Amine-functionalized alpha-cyanostilbene derivatives (Z)-2-(4-aminophenyl)-3-(4-butoxyphenyl) acrylonitrile (ABA) and (Z)-3-(4-butoxyphenyl)-2-[4-(butylamino) phenyl] acrylonitrile (BBA) were designed for specific recognition of picric acid (PA), an environmental and biological pollutant. The 1:1 host-guest complexes formed between the chemosensors and PA enhanced fluorescence quenching, thus leading to sensitive and selective detection in aqueous media and the solid phase.
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| 2. |
- Hao, Fuying, et al.
(författare)
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Design, crystal structures and enhanced frequency-upconverted lasing efficiencies of a new series of dyes from hybrid of inorganic polymers and organic chromophores
- 2009
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Ingår i: Journal of Materials Chemistry. - : RSC Publishing. - 0959-9428 .- 1364-5501. ; 19:48, s. 9163-9169
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Tidskriftsartikel (refereegranskat)abstract
- A new series of hybrid dyes, trans-4-(4′-N,N-dialkylaminostyryl)-N-methyl pyridinium [Cd(SCN)3−]n [alkyl = Me(1), Et(2), Pr(3) and n–Bu(4)] have been successfully synthesized from hybrids of inorganic polymers and organic chromophores. The structures of four new hybrid dyes were characterized by single-crystal X-ray diffraction first. The particular features of the hybrid dyes are (1) the inorganic anions form isolated polymeric one-dimensional zig-zag chains of [Cd(SCN)3−]n with an extended π-conjugation system within the polymeric –[M–S–C≡N]–M… chain and high polarizabilities; and (2) the organic cationic chromophores determine their optical properties. Experimental results revealed that the TPA cross-section values and overall energy conversion efficiencies of hybrid dyes with different alkyl pendant groups have obviously increased from 1 to 4, and in particular, have been substantially enhanced compared to their corresponding iodide analogues 1′–4′. Therefore, we speculate that such increases are attributable to arrangements of infinite anionic [Cd(SCN)3−]n chains and synergic effects with chromophore cations.
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| 3. |
- Liu, Yuchen, et al.
(författare)
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Effect of probe pulse duration in picosecond ultrasonics
- 2022
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 120:20
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Tidskriftsartikel (refereegranskat)abstract
- Picosecond ultrasonics is a powerful tool for nanoscale metrology, giving access to dimensions and mechanical, thermal, and optical properties of nanomaterials. By monitoring the temporal evolution of the interaction of light with coherent acoustic phonons, also known as Brillouin oscillations, phonon lifetime and optical absorption can be measured. However, the extraction of these quantities can be inaccurate due to the common assumption of the infinite coherence length of probe pulses. Here, we demonstrate the effect of probe pulse duration on picosecond ultrasonic measurements numerically and experimentally. We establish a model that shows how the probe coherence length affects the measured signal loss and how we can overcome this limitation and measure an upper limit of the acoustic attenuation factor. The model is verified experimentally on a GaAs bulk substrate by varying the probe pulse duration, showing a strong effect for sub-100 fs pulses. Finally, we applied to CH3NH3PbBr3, where we reveal a high acoustic attenuation factor, which is in line with recent claims of strong anharmonicity in halide perovskites.
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| 4. |
- Tian, Yu-peng, et al.
(författare)
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Synthesis, crystal structure and NLO properties of a novel ruthenium(II) complex with unusual coordination mode
- 2005
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Ingår i: Transition metal chemistry (Weinheim). - : Kluwer Academic Publishers. - 0340-4285 .- 1572-901X. ; 30:7, s. 778-785
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Tidskriftsartikel (refereegranskat)abstract
- A new Schiff base 4-[N-hydroxyethyl-N-(methyl)amino]benzaldehyde S-methyl dithiocarbazate (HL, where H is a dissociable proton) and the ruthenium complex [Ru(bpy)2L]PF6 (bpy = 2,2′-bipyridine) have been synthesized. The structural determinations of the ligand and its ruthenium complex, by X-ray crystallography, show that the ligand is coordinated as a monoanionic bidentate N, S-donor, forming a four-member chelate ring with a bite angle of 65.91°. The complex shows intense MLCT transitions in the visible region. Fluorescent and electrochemical properties have been also studied. The complex in DMF solution exhibited a strong two-photon absorption (t.p.a.) at 532 nm nanosecond laser pulses. The t.p.a. coefficient β, t.p.a. cross-section σ and the third-order optical nonlinearity χ(3) of the complex and the ligand have been determined by the Z-scan technique.
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| 5. |
- Tian, Yupeng, et al.
(författare)
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Two novel two-photon polymerization initiators with extensive application prospects
- 2004
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Ingår i: Chemical Physics Letters. - : Elsevier. - 0009-2614 .- 1873-4448. ; 388:4-6, s. 325-329
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Tidskriftsartikel (refereegranskat)abstract
- Two novel two-photon polymerization initiators, 10-ethyl-3-E-(4-(N,N′-di-n-butylamino)styryl)phenothiazine 5 and 10-ethyl-3,7-E,E-bis(4-(N,N′-di-n-butyl amino)styryl)phenothiazine 6, have been efficiently synthesized with room temperature solid phase Wittig reaction. Two initiators were found to exhibit good single-photon fluorescence emission and their quantum yields, lifetimes and solvent effects have been studied in detail. Two-photon fluorescence spectra were investigated under 800 nm fs laser pulse and two-photon absorption (TPA) cross-sections of the initiators have been evaluated by theoretical calculation.Two-photon initiating polymerization microfabrication experiments have been carried out and artificial defects were made and polymerization mechanism was also discussed.
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| 6. |
- Zhang, Xuanjun, et al.
(författare)
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Self-assembly of Organic Chromophore with Cd-S Nanoclusters: Supramolecular Structures and Enhanced Emissions
- 2005
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 5:2, s. 565-570
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Tidskriftsartikel (refereegranskat)abstract
- By combination of the large organic cation [trans-4-(4-dimethylanilino-styryl)-N-methyl-pyridinium with nanocluster anions ([Cd4(SC6H5)10]2- for compound 1 and [Cd4(SC6H5)6I4]2- for compound 2), two new hybrids were obtained and the structure of the [Cd4(SC6H5)6I4]2- cluster was first characterized by single-crystal X-ray diffraction. A novel supramolecular dimer {[Cd4(SC6H5)10]2-}2, connected via strong π−π interactions, was observed in 1, whereas every two [Cd4(SC6H5)6I4]2- clusters in 2 were linked by multiple C−H···I hydrogen bonds forming dimers, which, as building blocks, were further connected to each other via C−H···I hydrogen bonds and weak I···I interactions to form novel 1D helical chains. The UV−visible−near-IR spectra, one-photon excited photoluminescence, and two-photon pumped lasing were measured. The organic chromophore exhibits enhanced PL and two-photon pumped lasing in the two hybrids
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