Pb3Ba3Zn6(BO3)8 and α-BaZn2(BO3)2: new members of the zincoborates containing two different dimensional Zn–O units†
Two new zincoborates, namely, Pb3Ba3Zn6(BO3)8 and α-BaZn2(BO3)2, were synthesized by the high-temperature solution method and their structures were determined by single-crystal X-ray diffraction for the first time. The structure of Pb3Ba3Zn6(BO3)8 can be described as a three-dimensional framework consisting of [Zn4B2O15]∞ chains and isolated ZnO4 tetrahedra and BO3 triangles, which contains three different types of tunnels with Pb2+ and Ba2+ cations residing among them. α-BaZn2(BO3)2 exhibits a two-dimensional layered structure with a [Zn2B2O6] layer, which is formed by [ZnBO4] chains and [Zn2B2O8] chains. Interestingly, both Pb3Ba3Zn6(BO3)8 and α-BaZn2(BO3)2 both contain two different dimensional Zn–O configurations in their structures, which has not been found in other zincoborates. In addition, thermal property analysis, and UV-vis-NIR diffuse reflectance and infrared spectroscopy were also performed. First-principles theoretical studies were also conducted to aid the understanding of their band structures and densities of states.