The photoluminescence study of an organic–inorganic hybrid Keggin-type polyoxotungstate: A better excitation efficiency between polyoxometalate and thulium

Abstract

An organic–inorganic hybrid thulium-based polyoxometalate was synthesized and further studied using several physicochemical methods and photoluminescence. • an organic–inorganic hybrid Keggin-type polyoxotungstate was synthesized. • its photoluminescence is studied in detailed. • energy transfer efficiency form POM fragment to Tm 3+ ion can be found. An organic–inorganic hybrid lanthanide-based POM (Ln-POM) [N(CH 3 ) 4 ] 3 K 2 [Tm(C 7 H 5 O 3 )(H 2 O) 2 (α-PW 11 O 39 )]·10H 2 O ( 1 ) was synthesized and further characterized by single crystal X-ray diffraction analysis and other analyses. The physicochemical analyses indicate that POM fragments, organic ligand and Tm 3+ ion exist in compound 1 . The photoluminescence studies show that the photoexcitation O → M ligand to metal charge transfer (LMCT) of POM fragments can motivate the emissions of Tm 3+ ions within 1 . A much better excitation efficiency between POM fragment and Tm 3+ ion can be found in this organic–inorganic hybrid Ln-POM, and the unusual phenomenon can be explained that the emission of POM fragment can match well with the emission of Tm 3+ ion, yet the emission of organics is not consistent with emission of Tm 3+ ion in 1 .