Reversible proton-switchable fluorescence controlled by conjugation effect in an organically-functionalized polyoxometalate.
A novel monosubstituted organoimido hexamolybdate containing 6-nitroquinoline moiety has been successfully synthesized. This organically-functionalized polyoxometalate exhibits proton-induced switchable fluorescence property in aqueous acetonitrile solution at room temperature. Experimental and theoretical investigations of this reversible "on" and "off" switching mechanism have been carried out, and it is found that the protonation and deprotonation at the heterocyclic nitrogen atom within quinoline fragment leads to the breaking and reformation of the conjugation through strong d-π interaction between the hexamolybdate anionic cluster and the quinoline moiety, resulting in "on" and "off" luminescence signal.
Department of Chemistry, Tsinghua University, Beijing 100084, China.
Chunlin
C
Lv
Department of Chemistry, Tsinghua University, Beijing 100084, China.
Kun
K
Chen
Solid Waste and Chemicals Management Center, Ministry of Environmental Protection, Beijing 100029, China.
Junjie
J
Hu
Department of Chemistry, Tsinghua University, Beijing 100084, China.
Jin
J
Zhang
Department of Chemistry, Tsinghua University, Beijing 100084, China.
Rao Naumaan Nasim
RN
Khan
Department of Chemistry, Tsinghua University, Beijing 100084, China.|State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100191, China.
Yongge
Y
Wei