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

A dl-alanine covalently bonded giant arsenotungstate, namely, 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)}] ( 1 ; dl-Ala = dl-alanine), has been synthesized and is composed of six [AsW 9 O 33 ] 9- fragments fused together via two [W 2 O 5 (H 2 O)(dl-Ala)] + segments, two [W 3 O 6 (H 2 O)(dl-Ala)] 5+ segments, and a [W 2 O 5 (dl-Ala)] + segment. This complex represents the first carboxylate-based hybrid polyoxotungstate without the introduction of lanthanide ions. Besides, compound 1 demonstrates not only fast photochromic properties but also interesting proton conductivity properties, with an achieved conductivity of 2.830 × 10 -4 S·cm -1 (65 °C, 75% relative humidity).