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

Abstract

Three isostructural dl-serine covalently functionalized and multinuclear lanthanide (Ln3+)-embedded arsenotungstates, K2[{As4­W44O137­(OH)18(H2O)2­(dl-Ser)2}­{Ln2­(H2O)4(dl-Ser)}2­{Ln(H2O)7}2]·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 ∼20 h in the dark. The coloration kinetic half-life (t 1/2) 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.

dl-Alanine Covalently Bonded Giant Arsenotungstate with Rapid Photochromic and Decent Proton Conduction Properties

“…Furthermore, the photochromic kinetic results were in good agreement with the function R λ=680(t) = a /( bt +1) + c , similar to that reported by Dessapt’s group . Compound 1 demonstrated a faster photochromic rate ( t 1/2 = 0.698 min) than previously reported compounds, as summarized in Table S3. ,− ,,, The coloration kinetic parameters are listed in Figure d. On top of that, the photochromic kinetic process was further fitted in a linear correlation manner using a ln­[( R 0 – R )/( R t – R )] versus t plot, , thereby the rate constant was calculated as k = 0.0527 s –1 (Figure S15).…”

“…44 Compound 1 demonstrated a faster photochromic rate (t 1/2 = 0.698 min) than previously reported compounds, as summarized in Table S3. 23,[37][38][39]41,46,47 The coloration kinetic parameters are listed in Figure 3d. On top of that, the photochromic kinetic process was further fitted in a linear correlation manner using a ln[(R 0 − R)/(R t − R)] versus t plot, 47,48 thereby the rate constant was calculated as k = 0.0527 s −1 (Figure S15).…”

Discovery and Isolation of Two Arsenotungastate Species: [As4W48O168]36– and [As2W21O77(H2O)3]22–

“…Nevertheless, there should be more room for the exploration of new AT species because the lone-pair electrons of the As atom do not allow the closed Keggin unit to be obtained. Our group also synthesized many AT derivatives, which contributed to the development of ATs. − Inspired by this work, we present the structures of two new AT species, K 7 H 29 ­[As 4 W 48 O 168 ]·51H 2 O ( 1 ; Figure S1), and Cs 11 H 11 ­[As 2 W 21 O 77 ­(H 2 O) 3 ]·14H 2 O ( 2 ; Figure S2), which were synthesized in an aqueous medium at room temperature. The two compounds demonstrate the feasibility of synthesizing novel AT derivatives by {As 2 W 19 }.…”

A d-Methionine-Bonded Nanosized Heteropolyoxotungstate with Photocoloration

“…), which display rapid photochromism properties. 34,35 These carboxylate-based giant hybrid POTs contain lanthanide ions (Ln 3+ ), which possess diverse coordination environments and high coordination numbers. 33,36−39 Very recently, our group synthesized a giant hybrid arsenotungstate without the bridging Ln 3+ ions involved, N a Compound 1 was characterized by IR spectroscopy (Figure S1), powder X-ray diffraction (PXRD; Figure S2), thermogravimetric analysis (TGA; Figure S3), and UV−vis absorption spectroscopy (Figure S4).…”

“…33,36−39 Very recently, our group synthesized a giant hybrid arsenotungstate without the bridging Ln 3+ ions involved, N a Compound 1 was characterized by IR spectroscopy (Figure S1), powder X-ray diffraction (PXRD; Figure S2), thermogravimetric analysis (TGA; Figure S3), and UV−vis absorption spectroscopy (Figure S4). Compound 1 crystallized in the monoclinic P2 1 /n space group (Table S1), which contains a giant nanosized polyanion, namely, a general formula of 34− , 9 Ba 2+ and 10 K + cations, 6 H + , and approximately 60 crystal water molecules. All of the W and As atoms are 6+ and 3+, as confirmed via bond-valencesum (BVS) calculations (Table S2) and X-ray photoelectron spectroscopy (XPS) spectra (Figure S5).…”