z K nstallogr.yutsrqponmlihfedcbaSPNHCBA NCS_218_(2003) 165-166 165 ©by Oldenbourg Wissenschaftsverlag, München Crystal structure of sodium cadmium diaquayutsrponmlkhecbaXVNI catena - [monoboro· diphosphate]-hydrate, NaCd(H 2 0)2[BP 2 08] · 0.8H 2 0 wusponihgfedaZYXTRPMKJHGCB M.-H. Ge in , J.-X. Mi 1 , Y.-X. Huang™ , J.-T. Zhao*· 11 and R. Kniep™ 1 Xiamen University, College of Chemistry and Chemical Engineering, Xiamen 361005, P. R. China " Chinese Academy of Sciences, Shanghai Institute of Ceramics, The State Key Lab of High Performance Ceramics and Superfine Structure, 1295 Dingxi Road, Shanghai 200050, P. R. China xutsrqnmlkigfedcbaPM 111 Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, D-01187 Dresden, Germany Received January 23, 2003, accepted and available on-line April 10, 2003; CSD-No. 409680 gf °w% Abstract BCdH 6 NaOio.sP2, hexagonal, P6i22 (No. 178), a = 9.713(1) Â, c= 16.136(3) Â, V= 1318.4 À 3 ,zyxwvutsrponmlkjihgfedcbaZWTSRPONMLKIHFEDCBA Ζ = 6,xutsrmlkhgebaRKF R gt (F) = 0.047, w^reffF 2 ) = 0.105, Τ =2Ί 3 Κ . utsronmlifecaSD Source of material NaCd(H 2 0)2[BP 2 08] · 0.8H 2 0 was prepared under mild hydro- thermal conditions. A mixture of0.459 g CdCl 2 • 2.5H 2 0,1.900 g Na 2 B 4 0 7 · 10H 2 0,6.436 g NaB0 2 · 4H 2 0, and 5 ml (85%) H3PO4 was heated at 363 Κ in deionized water (10 ml) under stirring until the components were completely dissolved. The clear solution (pH = 2.0) was transferred to a teflon autoclave (internal volume 27 ml) with filling degree 70% and heated at 443 Κ for four days. All the starting materials were of analytical grade without further purification. The chemical composition of the title compound was confirmed by ICP-AES analysis. Discussion A considerable number of borophosphates has been characterized in the past few years; however no cadmium based compounds have been reported so far. Here we report the first Cd-based borophosphate, NaCd(H 2 0) 2 [BP 2 0 8 ] · 0.8H 2 0. Its crystal struc- ture belongs to the family of borophosphate-hydrates with the general formula M., 1 M v n (H 2 0) 2 [BP 2 0g] · ,Ή 2 0 (M 1 = Li, Na, K. Rb, Cs; M n = Mg, Μ η , Fe, Co, Ni, Zn, Cu; χ = 0.35 - 1, y = 1 -1.3, ζ = 0 . 2 - 1 ) [1,2], The crystal structure of the title compound contains infinite one-dimensional anionic tetrahedral ribbons j{[BP 2 0s] 3 ~}, which form helical arrangements around the 61 screw axis. The spiral ribbons are built up from four-membered rings in which BO4 and PO4 groups alternate. Each BO4 belongs to two adjacent four-membered rings of tetrahedra along the ribbon in such a way that all vertices of the BO4 tetrahedra participate in bridging func- tions with PO4 tetrahedra. The free loops of the borophosphate helices are occupied by Na + cations, which are surrounded by six oxygen atoms from adjacent phosphate groups (02) and water molecules (04H 2 O, 06H 2 O) in an irregular environment. The dou- ble helix j{Na[BP 2 0 8 ] 2 "} is completed by forming a central channel running along the 61 screw axis. The channel is filled with disordered water molecules (06H 2 O), resulting in the formula {Na[BP 2 0s] 2_ · 0.8H 2 0}. The Cd 2+ ions are coordinated to four oxygen atoms of PO4 groups (02, 05) and two water molecules (04H 2 O), resulting in an octahedral coordination Cd(Op)4(OH 2 o) 2 connecting neighboring ribbons. Bond lengths and angles within the anionic partial structure are consistent with related borophosphates [3-6]. Table 1. Data collection and handling. Crystal: colorless hexagonal bipyramid, size 0.08 χ 0.08 χ 0.09 mm Wavelength: Mo K a radiation (0.71073 Â) μ : 29.48 cnT 1 Diffractometer, scan mode: Brucker SMART CCD, ω /φ 20 m ax: 56.46° Ν (hkl)measureá, N(hkl)unique: 8039, 1072 Criterion for I 0 bs, N(hkl) g t: lobs > 2 a(Iobs), 1072 N(param)re fmed: 77 Programs: SHELXL-97 [7], DIAMOND [8] Table 2. Atomic coordinates and displacement parameters (in A ). Correspondence author (e-mail: jtzhao@mail.sic.ac.cn) Atom Site Occ. X y ζ c/iso 0(6) 6a 0.80 0.889(6) 0 0 0.23(3) Β 6b 0.1525(7) 2x 1/4 0.015(2) H(l) 12c 0.94(2) -0.15(1) 0.231(9) 0.05 H(2) 12c 0.61(2) 0.17(1) 0.048(8) 0.05 H(3) 12c 0.8094 0.2446 0.0332 0.05 Unauthenticated Download Date | 3/15/16 11:54 AM