Cylindrical HP III -Sb III -Templated Five-Layer Polyoxotungstate with Conspicuous Photochromism Triggered by UV or Visible Light.

The heteroanion (HA) component plays an important role in the templating of heteropolyoxometalate (HPA) structures, but polyoxometalates (POMs) formed from two different templates are rarely reported. Herein, we present a five-layer POM [H 2 N(CH 3 ) 2 ] 14 {[(HPO 3 ) 4 W 6 O 10 ][HPSbW 15 O 54 ] 2 }·16H 2 O ( 1 ) prepared by two kinds of different HA templates. The multilayer heteropolyanion {[(HPO 3 ) 4 W 6 O 10 ][HPSbW 15 O 54 ] 2 } 14- in 1 consists of two trivacant diheteroatom-templated ([HPO 3 ] 2- and [SbO 3 ] 3- ) [HPSbW 15 O 54 ] 11- subunits linked by one unusual [(HPO 3 ) 4 W 6 O 10 ] 8+ subcluster via twelve corner-sharing oxygen atoms. Compound 1 was systematically characterized by IR, UV, PXRD, TGA, XPS, and Raman spectra. Compound 1 exhibits good photochromism under UV irradiation with a half-life ( t 1/2 ) of 42.5 s, and it also exhibits noteworthy photochromism under visible light irradiation with a half-life ( t 1/2 ) of 157.2 s. The possible photochromic mechanism is proposed and verified by the experimental results.