Syntheses And Crystal Structures Of Novel Boron Materials

Because the boron atoms coordinate with oxygen not only in three-fold coordination (triangular, BO3) but also in four-fold coordination (tetrahedral, BO4), there are many kinds of borates with complex structures. In this paper, we synthesized a series of new borates, and characterized them through IR, TG-DTG, XRD. The crystal structures of new borates have been determined by the single crystal X-ray diffraction.Four novel crystal structures have been prepared by hydrothermal synthesis, including Li[NiBP2O8 (H2O)2]·(H2O),LiCu2BP2O8(OH)2,Mn(C2O4)Mn3(PO4)2·2H2O and Ba5Cl4(O H)6·2H2O·(PVO5)8. Single-crystal X- ray intensity data were collected on Bruker APEX-II CCD single crystal diffractometer. The crystal structures were solved by the SHELXITL software.The compound of Li[NiBP2O8 (H2O)2]·(H2O) belongs to hexagonal system, P6522 space group, a = 9.3359 (3) ?,b = 9.3359 (3) ?,c = 15.7497 (11) ?,γ=120°,Z=12. The one-dimensional helical∞1[BP2O8]3- is connected to three-dimensional open framework structure by the connection of Ni atoms.The compound of LiCu2BP2O8(OH)2 belongs to monoclinic system, C2/c space group, a = 15.0974 (19) ?,b = 4.7617 (6) ?,c = 9.6585 (12) ?,β= 91.0190 (10)°, Z=4. BO4 and PO4 are connected to [BP2O8]3- anion by two sharing O atoms, and CuO6, LiO6 are octahedron. The one-dimensional chain is composed by [BP2O8]3- anion and Li atom. The one-dimensional chain is connected to three-dimensional open framework structure by the connection of Cu atoms.The compound of Mn(C2O4)Mn3(PO4)2·2H2O belongs to monoclinic system,P21/c space group,a = 10.2759 (2) ?,b = 6.5220 (1) ?, c = 10.0701 (1) ?,β= 116.926 (1)o, Z= 2。Mn1 has a MnO6 octahedral coordination environment, but Mn2 is coordinated with five oxygen atoms,The distorted octahedral MnO6 and tetragonal pyramidal MnO5 centers are linked through bridging oxalate and phosphate groups.The compound of Ba5Cl4(O H)6·2H2O·(PVO5)8 belongs to orthorhombic, Cmca space group, a = 13.5073(8) ?,b = 8.8803 (5) ,c = 35.482 (2) ?,Z=4. Compound Ba5Cl4(OH)6·2H2O·(PVO5)8 consists of layers built from the new large neutral oxovanadium phosphate (PVO5) and neutral barium chlorine alkaline hydrate Ba5Cl4(OH)6·2H2O alternately.The research results of this thesis enrich the contents of crystal material, laying the foundation for its wide application.