Two Heart-Shaped Carboxylate-Substituted Selenotungstates with Photochromic Properties

Two carboxylate-substituted selenotungstates with heart-shaped structures were successfully synthesized via the reaction of Na 2 SeO 3, Na 2 WO 4 ·2H 2 O, dl -malic acid/glycolic acid, and dimethylamine hydrochloride in an aqueous solution. The chemical formulas of these compounds are [(CH 3 ) 2 NH 2 ] 8 Ba 2 Na 2 (H 2 O) 7 [Se 4 W 31 O 104 (OH) 4 (H 2 O)(MalH) 2 ]·18H 2 O ( 1 ) and [(CH 3 ) 2 NH 2 ] 12 Ba 3 (H 2 O) 8 [Se 4 W 31 O 108 (H 2 O)(Gca) 2 ]·20H 2 O ( 2 ) [Mal = malate; Gca = glycolate]. The most notable structural characteristic of these compounds is the presence of a carboxylate-substituted selenotungstate framework, a feature that is relatively uncommon among the previously reported selenotungstates. Furthermore, the experimental results demonstrate that these compounds exhibit photochromic properties.