Synthesis,crystal structure and properties of a new congruently melting compound,K3ZnB5O10

A new compound, K₃ZnB₅O₁₀, has been synthesized by solid-state reaction. It crystallizes in the monoclinic system, space group P2₁/n with unit–cell parameters a = 7.6391(5) Å, b = 19.2304(13) Å, c = 7.6905(5) Å, β = 116.698(4)° and Z = 4. The structure of the compound is solved by the direct methods and refined to R1 = 0.0286 and wR2 = 0.0600. K₃ZnB₅O₁₀ contains a two-dimensional ZnB₅O₁₀ layer, which forms by connecting isolated double ring [B₅O₁₀] groups and ZnO₄ tetrahedra. The K atoms filling in the interlayer and intralayer link the layers together. Functional groups presented in the sample were identified by FTIR spectrum. UV–vis–NIR diffuse reflectance spectrum exhibits ultraviolet cutoff edge is about 190 nm. The DSC analysis proves that K₃ZnB₅O₁₀ is a congruently melting compound.