Ionothermal Syntheses and Characterizations of New Open-Framework Metal Borophosphates
journal contributionposted on 2011-02-07, 00:00 authored by Tan Su, Hongzhu Xing, Jin Xu, Jihong Yu, Ruren Xu
Three new open-framework metal borophosphates, [Na6Co3B2P5O21Cl]·H2O (JIS-4), K5Mn2B2P5O19(OH)2 (JIS-5), (NH4)8[Co2B4P8O30(OH)4] (JIS-6), have been prepared under ionothermal conditions using ionic liquid 1-ethyl-3-methylimidazolium ([Emim]Br) as the solvent. They are the first examples of metalloborophosphate prepared by the ionothermal method. Their structures are determined by single-crystal X-ray diffraction. The 3-D open framework of JIS-4 is made of CoO5Cl octahedra, CoO5 square pyramids, and PO4 and BO4 tetrahedra forming 12-ring channels along the  direction. It is noted that JIS-4 is the first 3-D open-framework structure in the family of borophosphate with the B/P ratio of 2/5, which features a borophosphate cluster anionic partial structure. Such cluster anionic partial structures connect with MnO6 octahedra and MnO5 trigonal bipyramids resulting in the formation of the 2-D layer structure of JIS-5 with the same B/P ratio as JIS-4. The 2-D layer structure of JIS-6 belongs to the largest family of borophosphate with a B/P ratio of 1/2 which features a unique 1-D chain anionic partial structure. Crystal data for JIS-4, orthorhombic, Pnma, a = 14.0638(8) Å, b = 9.8813(7) Å, c = 14.0008(10) Å, V = 1945.7(2) Å3, and Z = 2; for JIS-5, monoclinic, P21/n, a = 14.4939(3) Å, b = 9.2539(3) Å, c = 14.8031(4) Å, β = 101.4600(10)°, V = 1945.88(9) Å3, and Z = 4. For JIS-6, triclinic, P1, a = 9.6928(3) Å, b = 9.8747(3) Å, c = 10.0125(2) Å, α = 62.057(2)°, β = 82.456(2)°, γ = 76.095(2)°, V = 821.60(4) Å3, and Z = 1.