Crystallization-induced emission enhancement: A novel fluorescent Au-Ag bimetallic nanocluster with precise atomic structure.
Tao ChenSha YangJinsong ChaiYongbo SongJiqiang FanBo RaoHongting ShengHai-Zhu YuMan-Zhou ZhuPublished in: Science advances (2017)
We report the first noble metal nanocluster with a formula of Au4Ag13(DPPM)3(SR)9 exhibiting crystallization-induced emission enhancement (CIEE), where DPPM denotes bis(diphenylphosphino)methane and HSR denotes 2,5-dimethylbenzenethiol. The precise atomic structure is determined by x-ray crystallography. The crystalline state of Au4Ag13 shows strong luminescence at 695 nm, in striking contrast to the weak emission of the amorphous state and hardly any emission in solution phase. The structural analysis and the density functional theory calculations imply that the compact C-H⋯π interactions significantly restrict the intramolecular rotations and vibrations and thus considerably enhance the radiative transitions in the crystalline state. Because the noncovalent interactions can be easily modulated via varying the chemical environments, the CIEE phenomenon might represent a general strategy to amplify the fluorescence from weakly (or even non-) emissive nanoclusters.
Keyphrases
- quantum dots
- sensitive detection
- density functional theory
- energy transfer
- visible light
- solid state
- molecular dynamics
- room temperature
- high glucose
- diabetic rats
- drug induced
- magnetic resonance
- highly efficient
- photodynamic therapy
- molecular dynamics simulations
- ionic liquid
- magnetic resonance imaging
- computed tomography
- mass spectrometry
- electron microscopy
- oxidative stress
- living cells
- preterm infants
- fluorescent probe
- preterm birth
- low birth weight