Ba 4 M(CO 3 ) 2 (BO 3 ) 2 (M=Ba, Sr): two borate-carbonates synthesized by open high temperature solution method

Abstract

Two borate-carbonates Ba 4 M(CO 3 ) 2 (BO 3 ) 2 (M = Ba, Sr) have been successfully synthesized in the open air representing the first examples of borate-carbnate complex. Their structures were determined by single crystal X-ray diffraction and they both crystallize in same space group, Pnma. Their structures feature a Ba/Sr-based three dimensional framework composed of the BaO 8 polyhedra (the SrO 8 polyhedra), isolated BO 3 and CO 3 triangles. Detailed structure analysis shows that the intergrowth of [Ba 3 (BO 3 ) 2 ]/[Ba 2 Sr(BO 3 ) 2 ] and [BaCO 3 ] layers favors the formation of these two borate-carbonates. In addition, their syntheses, spectroscopic properties and thermal behaviors were investigated.