Synthesis, crystal structure, and spectrum properties of a new borate Ba₄K₂Zn₅(B₃O₆)₃(B₉O₁₉) with two isolated types of blocks: 3[3螖] and 3[2螖聽+聽1T]聽+聽3螖聽+聽3[2螖聽+聽1T]

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• 作者：Xuean Chen ; Yanjun Chen ; Long Wu ; Xinan Chang ; Weiqiang Xiao
• 关键词：Ba4K2Zn5(B3O6)3(B9O19) ; Borate ; X-ray diffraction ; Crystal structure
• 刊名：Solid State Sciences
• 出版年：January, 2014
• 年：2014
• 卷：27
• 期：Complete
• 页码：47-54
• 全文大小：1462 K

文摘

A new barium potassium zincoborate, Ba₄K₂Zn₅(B₃O₆)₃(B₉O₁₉), has been synthesized by high-temperature solution reaction at 750聽掳C. Its crystal structure was established by single-crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2₁/n (No. 14) with cell parameters of a聽=聽7.1620(14)聽脜, b聽=聽38.772(8)聽脜, c聽=聽12.360(3)聽脜, 尾聽=聽90.26(3)掳, V聽=聽3432.2(12)聽脜³, and Z聽=聽4. It has a new structure type that features two-dimensional anionic layers composed of ZnO₄ tetrahedra, [B₃O₆]^{3鈭?/sup> rings with notation of 3[3螖], and [B₉O₁₉]11鈭?/sup> groups with notation of 3[2螖聽+聽1T]聽+聽3螖聽+聽3[2螖聽+聽1T], where 螖 and T represent BO₃ triangles and BO₄ tetrahedra, respectively. The zinc borate anionic layers stack along b-axis, with the intralayer open channels and interlayer void spaces filled by Ba2+, K+, or Ba2+/K+ cations to compensate the negative charges of the layers. Infrared spectrum was measured, which confirms the presence of both BO₃ and BO₄ groups. The optical properties were investigated in terms of diffuse reflectance and fluorescence spectra, which reveal an optical band gap of 3.18聽eV as well as a broad emission band at around 515.8聽nm upon laser excitation at 325聽nm.}