Energy transfer is of vital importance within many significant processes including the combustion of matter, the generation of electricity, photosynthesis, etc. Fluorescence (or Förster) resonance energy transfer (FRET) describes the energy transfer between different chromophores through nonradiative dipole-dipole coupling. A well-known FRET system is the energy transfer from carotenoids to chlorophyll in natural photosynthesis, which is considered as the most important chemical reaction on the earth. Efficient FRET not only requires suitable distance between the energy donors and acceptors as well as good spectral overlap between the emission of the donors and the excitation of the acceptors, but also requests a certain directivity to facilitate the coupling of dipoles. Flexible covalent bonds and most supramolecular forces can hardly hold the FERT process in a certain direction. Therefore, it is challenging to realize and regulate the FERT process in a specific position and direction.
In order to solve this problem, two TPE-based tetragonal prismatic platinum(II) cages were prepared by Supramolecular Materials Laboratory of our school via metal-coordination-driven self-assembly of different fluorescent ligands. The FRET was efficiently controlled either from the pillars to the faces or from the faces to the pillars. Moreover, because the faces are aggregation induced emission (AIE) fluorophores while the pillars are aggregation caused quenching (ACQ) fluorophores as well as their structural differences, they show different responses to temperature, mechanical pressure, and solvent composition and polarity. Such different responses further affect the spectral overlap between the energy donors and acceptors, making these metallacages very sensitive to environmental changes. Therefore, these metallacages can act as sensors for temperature, pressure and solvents. This study not only offers a convenient method to prepare supramolecular coordination complexes (SCCs) with efficient energy transfer but also explores their application towards probing and sensing, which will facilitate the development of stimuli-responsive light-emitting materials.
Recently, this work entitled ‘Emissive Platinum(II) Cages with Reverse Fluorescence Resonance Energy Transfer for Multiple Sensing’ was published on Journal of the American Chemical Society. Prof. Mingming Zhang from our university and associate Prof. Kai Wang from Jilin university are the co-corresponding authors. Dr. Zeyuan Zhang and Zhengqing Zhao are the co-first authors for this work. The first unit is State Key Laboratory for Mechanical Behavior of Materials of our university.
This work was supported by the National Natural Science Foundation of China, National Institutes of Health of USA and start-up funds from Xi’an Jiaotong University, and assisted by Prof. Xiaopeng Li from University of South Florida, Dr. Sanling Lin from University of Nottingham, Prof. Bo Zou from Jilin University, Prof. Gang He from Frontier Institute of Science and Technology of our university, and researchers from Instrument Analysis Center of our university.
Link for this paper：https://pubs.acs.org/doi/10.1021/jacs.9b12689.
