Lanthanide hybrids of covalently-coordination cooperative post-functionalized metal–organic frameworks for luminescence tuning and highly-selectively sensing of tetrahydrofuran

Abstract

A new class of Ln-MOFs (Ln = Eu, Tb, Eu/Tb, Sm) are synthesized through a post-synthetic modification of the parent MOF, UMCM-NH₂. The luminescence spectra of Eu-MOF, Tb-MOF and Eu/Tb-MOF exhibit the characteristic emission bands of ligands and corresponding Ln³⁺, particularly Eu³⁺. Multi-color luminescence could be modulated by adjusting the excitation wavelength of the Eu-MOF and Tb-MOF. What's more, white-light emission may be realized by co-doping the Eu³⁺ and Tb³⁺ due to the synergistic contribution of the three luminescence centers. In addition, the Eu-MOF is selected as a luminescence sensor to explore the potential of sensing organic small molecules. Most interestingly, it exhibits a highly selective, sensitive and rapid response to THF, which could be distinguished easily by the naked eye under UV-light irradiation. Consequently, Eu-MOF is a promising candidate as the “turn on” fluorescent probe for detecting THF that has been rarely reported.