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

A d-Methionine-Bonded Nanosized Heteropolyoxotungstate with Photocoloration

“…The coloration speed of 1 is distinctly faster than that of most photocoloration POM derivatives as reported previously, 34,35,37,45−48 although it is slightly lower than that of the POT {As 6 W 66 } with photocoloration reported by our group very recently. 40 The main reason is probably due to the relatively smaller number of hydrogen bonds between POT skeletons and amino acid ligands in 1. This is also consistent with previous discussions.…”

“…Of particular concern is the structural difference between 1 and the organic−inorganic hybrid compound {As 6 W 66 } reported by our group recently. 40 S3, which is critical to enhancing its photocoloration behavior. Noticeably, solid powder 1 exhibited a remarkable color evolution from canary yellow in its original state to naked-eyesaturated blue within 110 s upon irradiation (Figure 2a).…”

“…Very recently, our group synthesized a giant hybrid arsenotungstate without the bridging Ln 3+ ions involved, Na 3 Ba 11 H 16 ­[(AsW 9 O 33 ) 6 ­{W 2 O 5 (H 2 O)­( dl -Ala)} 2 ­{W 3 O 6 (H 2 O)­( dl -Ala)} 2 ­{W 2 O 5 ( dl -Ala)}] (abbreviated as {As 6 W 66 }) . During the extended research efforts, we elaborately obtained a d -methionine-based nanosized hybrid heteropolyoxotungstate, Ba 9 K 10 H 6 ­[{As 2 W 19 O 67 ­(H 2 O)} 2 ­{AsW 9 O 33 } 2 ­{W 3 O 6 (H 2 O)­( d -Met)} 2 ­{W 2 O 4 (OH)­( d -Met)}]·60H 2 O [ 1 ; d -Met = d -methionine (C 5 H 11 NO 2 S)].…”

“…As is known, the structural transformation of precursor {As 2 W 19 O 67 (H 2 O)} 14– (abbreviated as {As 2 W 19 }) is unexpected in an aqueous solution. ,− As illustrated in Figure a,b, the angle [119.5(4)°] in 1b is larger than that of the precursor {As 2 W 19 } [114.4(1)°] during the synthesis of compound 1 . In detail, the {As 2 W 19 O 67 (H 2 O)} 14– building block of 1 can be unambiguously identified as a derivative of the precursor {As 2 W 19 } formed via an edge-sharing {W 3 O 13 } unit rotated by 60°.…”

“…Of particular concern is the structural difference between 1 and the organic–inorganic hybrid compound {As 6 W 66 } reported by our group recently …”