Pb3Ba3Zn6(BO3)8 and α-BaZn2(BO3)2 : New Members of the Zincoborates Containing Two Different Dimensional Zn-O Units
Two new zincoborates, 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 is two dimensional layered structure with [Zn2B2O6] layer which is formed by [ZnBO4] chains and [Zn2B2O8] chains. Interestingly, both Pb3Ba3Zn6(BO3)8 and α-BaZn2(BO3)2 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.