Coordination-Enhanced Luminescence on Tetra-Phenylethylene-Based Supramolecular Assemblies

Qian-Qian Yan; Shao-Jun Hu; Guang-Lu Zhang; Ting Zhang; Li-Peng Zhou; Qing-Fu Sun

doi:10.3390/molecules23020363

Coordination-Enhanced Luminescence on Tetra-Phenylethylene-Based Supramolecular Assemblies

Molecules. 2018 Feb 9;23(2):363. doi: 10.3390/molecules23020363.

Authors

Qian-Qian Yan^{1

2}, Shao-Jun Hu^{3

4}, Guang-Lu Zhang⁵, Ting Zhang⁶, Li-Peng Zhou⁷, Qing-Fu Sun⁸

Affiliations

¹ College of Chemistry, Fuzhou University, Fuzhou 350108, China. yanqianqian@fjirsm.ac.cn.
² State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China. yanqianqian@fjirsm.ac.cn.
³ College of Chemistry, Fuzhou University, Fuzhou 350108, China. sjhu@fjirsm.ac.cn.
⁴ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China. sjhu@fjirsm.ac.cn.
⁵ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China. glzhang@sdnu.edu.cn.
⁶ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China. zhangting@fjirsm.ac.cn.
⁷ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China. zhoulp@fjirsm.ac.cn.
⁸ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China. qfsun@fjirsm.ac.cn.

Abstract

Materials with aggregation-induced emission (AIE) properties have received increased attention recently due to their potential applications in light-emitting devices, chemo/biosensors and biomedical diagnostics. In general, AIE requires the forced aggregation of the AIEgens induced by the poor solvent or close arrangement of AIEgens covalently attached to polymer chains. Here, we report two coordination-enhanced fluorescent supramolecular complexes featuring hierarchically restricted intramolecular motions via the self-assembly of tetraphenylethylene (TPE)-based tetra-dentate (L^a) and bidentate (L^b) ligands and the cis-Pd(en)(NO₃)₂ (en = ethylenediamine) unit. While the free ligands are non-emissive in dilute solution and show typical AIE properties in both mixed solvent system and the solid state, the self-assembled complexes maintain their fluorescent nature in the solution state. In particular, the Pd₄(L^a)₂ complex shows remarkable 6-fold fluorescent enhancement over L^a in dilute solution. We anticipate that these kinds of coordination-enhanced emissive supramolecules will find applications in biomedical sensing or labeling.

Keywords: AIE; coordination self-assembly; fluorescence enhancement; tetraphenylethylene.

MeSH terms

Coordination Complexes / chemistry*
Dimerization
Fluorescent Dyes / chemistry*
Isomerism
Ligands
Molecular Structure
Palladium / chemistry*
Spectrometry, Fluorescence / methods
Stilbenes / chemistry*

Substances

Coordination Complexes
Fluorescent Dyes
Ligands
Stilbenes
tetraphenylethylene
Palladium