Histidine-directed synthesis and optical properties of two indium phosphite–oxalates with three-dimensional structures

Abstract

Two indium phosphite–oxalates with three-dimensional structures have been synthesized under the structure-directing effect of histidine. In compound 1, histidine molecules act as terminal ligands, whereas in compound 2, they function not only as terminal ligands but also as extra framework cations. The dual role of histidine induces compound 2 to form a noncentrosymmetric structure with an interesting second-harmonic generation response. Both compounds 1 and 2 exhibit blue luminescence under ultraviolet light irradiation, originating from the histidine molecules.