abstract
Isostructural lanthanide organic frameworks (Me2NH2)(3)[Ln(3)(FDC)(4)(NO3)(4)]center dot 4H(2)O (Ln = Eu (1), Gd (2), Tb (3), H2FDC = 9-fluorenone-2,7-dicarboxylic acid), synthesized under solvothermal conditions, feature a Ln-O-C rod-packing 3D framework. Time-resolved luminescence studies show that in 1 the energy difference between the H2FDC triplet excited state (17794 cm(-1)) and the D-5(0) Eu3+ level (17241 cm(-1)) is small enough to allow a strong thermally activated ion-to-ligand back energy transfer. Whereas the emission of the ligand is essentially constant the D-5(0)-> F-7(2) intensity is quenched when the temperature increases from 12 to 320 K, rendering 1 the first single-lanthanide organic framework ratiometric luminescent thermometer based on ion-to-ligand back energy transfer. More importantly, this material is also the first example of a metal organic framework thermometer operative over a wide temperature range including the physiological (12-320 K), upon excitation with visible light (450 nm).
keywords
TEMPERATURE-MEASUREMENT; COORDINATION POLYMERS; ENERGY-TRANSFER; EMISSION; METAL; NANOTHERMOMETERS; DEPENDENCE; NANOSCALE; LIGAND; RANGE
subject category
Chemistry; Science & Technology - Other Topics; Materials Science; Physics
authors
Li, L; Zhu, YL; Zhou, XH; Brites, CDS; Ananias, D; Lin, Z; Paz, FAA; Rocha, J; Huang, W; Carlos, LD
our authors
Carlos Brites
Associate Professor
Duarte Ananias
Assistant Researcher
Filipe Alexandre Almeida Paz
Principal Researcher
João Rocha
Full Professor
Luís Carlos
Full professor
Zhi Lin
Principal Researcheracknowledgements
This work was supported by Natural Science Foundation of Jiangsu Province (BM2012010), Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) (YX03001), Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) (20113223110005), the National Basic Research Program of China (973 Program) (2012CB933301). This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (Fundacao para a Ciencia e a Tecnologia, FCT, Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC (Ministerio da Educacao e Ciencia) and when appropriate cofinanced by FEDER under the PT2020 Partnership Agreement. C.D.S.B. (SFRH/BPD/89003/2012) and D.A. (SFRH/BPD/95032/2013) thanks FCT for the postdoctoral grants.