A d-Methionine-Bonded Nanosized Heteropolyoxotungstate with Photocoloration.

A d-methionine-bonded nanosized arsenotungstate, 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)], is constructed without the use of lanthanide ions. The polyanion of 1 contains two {As 2 W 19 O 67 (H 2 O)} 14- building blocks and two {B-β-AsW 9 O 33 } 9- subunits, integrated together with a {W 2 O 4 (OH)(d-Met)} 2+ and two {W 3 O 6 (H 2 O)(d-Met)} 5+ subclusters. Interestingly, 1 displays a highly reversible photocoloration property with a half-life ( t 1/2 ) time measured as about 0.793 min.