DL-Serine Covalently Ornamented and Ln3+-Incorporated Arsenotungstates with Fast-Responsive Photochromic and Photoinduced Luminescent Switchable Behaviors

Three isostructural DL-serine covalently function-alized and multinuclear lanthanide (Ln3+)-embedded arsenotung-states, K2[{As4W44O137(OH)18(H2O)2(DL-Ser)2}{Ln2(H2O)4(DL- Ser)}2{Ln(H2O)7}2]center dot 70H2O (Ln = Sm (1), Eu (2), and Gd (3); DL-Ser = C3H7NO3), were prepared, where the centrosymmetric [{As4W44O137(OH)18(H2O)2(DL-Ser)2}{Ln2(H2O)4(DL-Ser)}2]8- polyanion consists of two {As2W19O59(OH)8(H2O)}6- fragments, integrated with a two-DL-serine-ornamented [W6O23(OH)2(DL- Ser)2{Ln2(H2O)4}2]8- segment. In addition, the photochromic transformation of solid-state compounds 1-3 was observed from colorless to blue after a UV illumination of 4 min, and the decay process lasted as long as similar to 20 h in the dark. The coloration kinetic half-life (t1/2) values of compounds 1, 2, and 3 were calculated to be 0.597, 0.920, and 0.723 min, respectively. Furthermore, the luminescent properties and energy migration from arsenotungstates and organic chromophores to Sm3+ and Eu3+ ions in 1 and 2 have been intensively investigated. Further analysis manifests that 1 possesses an effective luminescent switchable behavior, triggered by its fast-responsive photochromism effect.

Automated summary

The translation discusses the preparation and properties of three isostructural DL-serine covalently function-alized and multinuclear lanthanide-embedded arsenotungstates. The compounds exhibit photochromic transformation from colorless to blue, and luminescent properties with energy migration to Sm3+ and Eu3+ ions.