具有螺旋结构的新型硼磷酸盐化合物:(NH4)0.5(H3O)0.5Mg(H2O)2BP2O8

利用水热方法合成新型硼磷化合物:(NH4)0.5(H3O)0.5Mg(H2O)2BP2O8,单晶X射 线衍射分析证明化合物属六方晶系,空间群为P6522,a=0.94507(19)nm,c=1.5803(5) nm,γ=120°,V=1.2224(5)nm^3,Mr=279.06,Dc=2.258g/cm^3,Z=6,F(000)=834,μ =0.663mm^-1。结构中BO4,PO4基团形成∞^1{[BP2O8]^3-}的螺旋带与MgO6相连构 成八面体-四面体空间骨架,元素分析、IR光谱、热重差热分析和电荷平衡计算证 明晶体中含有NH4^+和质子。NH4^+占据螺旋带螺旋纹内,质子化的水分靠近螺旋带 通道的内侧,两者均起到平衡电荷和稳定骨架的作用。

A New Borophosphate Compound with Helix Structure: (NH_4)_(0.5) (H_3O)_(0.5)Mg(H_2O)_2BP_2O_8

A new borophosphate compound, (NrttVsCHaOVsMgC^O^I^Og, was prepared by hydrothermal synthesis and characterized by X-ray single crystal diffraction. The title compound belongs to hexagonal system, space group P6522, o=0.94507(19) nm, e = 1.5803(5) nm, 7 = 120°, V= 1.2224 (5) nm3, Mr = 279.06, Z = 6, Da = 2.258 g/cm3, F(000) = 834, Rx = 0. 0360, wR2 = 0.1070, p. = 0.663 mm"1. The crystal structure of the compound contains infinite one-dimensional borophosphate ribbons L ( [BP2O8]3~ | , built of corner sharing BO4 and PO4 tetrahedra arranged around 65 screw axes. The borophosphate helices are interconnected by MgO4(H2O)2 coordination octahedra to form a three-dimensional framework. The elemental analysis, IR, DTA/TGA and the calculation of the electric charge balance show the presence of ammonium ions and protons. Both ammonium ions and hydroniums are located within the free loop of helical ribbons, and close to the inner wall of the helical channels L I tBP2O8]3" I , respectively, balancing charge and stabilizing helical ribbons.