Gerd Schäfer

NaZn(H2O)2[BP2O8] · H2O: A Novel Open-Framework Borophosphate and its Reversible Dehydration to Microporous Sodium Zincoborophosphate Na[ZnBP2O8] · H2O with CZP-Topology

Crystals of NaZn(H2O)2[BP2O8].H2O were grown under mild hydrothermal conditions at 170 degrees C. The crystal structure (solved by X-ray single-crystal methods: hexagonal, P6(1)22 (no. 178), a = 946.2(2), c= 1583.5(1) pm, V= 1227.8(4).10(6) pm3, Z = 6) exhibits a chiral octahedral-tetrahedral framework related to the CZP topology and contains helical ribbons of corner-linked borate and phosphate tetrahedra. Investigation of the thermal behavior up to 180 degrees C shows a (reversible) dehydration process; this leads to the microporous compound Na[ZnBP2O8].H2O, which has the CZP topology. The crystal structure of Na[ZnBP2O8].H2O was determined by X-ray powder diffraction by using a combination of simulated annealing, lattice-energy minimization, and Rietveld refinement procedures (hexagonal, P6(1)22 (no. 178), a = 954.04(2), c = 1477.80(3) pm, V= 164.88(5).10(6) pm3, Z = 6). The essential structural difference caused by the dehydration concerns the coordination of Zn2- changing from octahedral to tetrahedral arrangement.

MII(C4H12N2)[B2P3O12(OH)] (MII = Co, Zn): Synthesis and Crystal Structure of Novel Open Framework Borophosphates

Two novel borophosphates, MII(C4H12N2)[B2P3O12(OH)] (MII = Co, Zn), exhibiting open frameworks, have been synthesized by hydrothermal reactions (T = 165 °C). The crystal structures of the isotypic compounds have been determined both at 293 K (orthorhombic, Ima2 (no. 46), Z = 4; MII = Co: a = 12.4635(4) A, b = 9.4021(4) A, c = 11.4513(5) A, V = 1341.90 A3, R1 = 0.0202, wR2 = 0.0452, 2225 observed reflections with I > 2σ(I); MII = Zn: a = 12.4110(9) A, b = 9.4550(5) A, c = 11.4592(4) A, V = 1344.69 A3, R1 = 0.0621, wR2 = 0.0926, 1497 observed reflections with I > 2σ(I)). Distorted CoO6-octahedra and ZnO5-square-pyramids, respectively, share common oxygen-corners with BO4-, PO4- and (HO)PO3-tetrahedra. The tetrahedral groups are linked via common corners to form infinite loop-branched borophosphate chains [B2P3O12(OH)4–]. The open framework of MII-coordination polyhedra and tetrahedral borophosphate chains contains a three-dimensional system of interconnected structural channels running along [100], [011] and [011], respectively, which are occupied by di-protonated piperazinium ions. MII(C4H12N2)[B2P3O12(OH)] (MII = Co, Zn): Darstellung und Kristallstrukturen neuer Borophosphate mit offenen Geruststrukturen Zwei neue Borophosphate mit offenen Geruststrukturen, MII(C4H12N2)[B2P3O12(OH)] (MII = Co, Zn), wurden unter hydrothermalen Bedingungen (T = 165 °C) dargestellt. Die Kristallstrukturen der isotypen Verbindungen (Einkristallmethoden; orthorhombisch, Ima2 (Nr. 46), Z = 4; MII = Co: a = 12,4635(4) A, b = 9,4021(4) A, c = 11,4513(5) A, V = 1341,90 A3, R1 = 0,0202, wR2 = 0,0452, 2225 beobachtete Reflexe mit I > 2σ(I); MII = Zn: a = 12,4110(9) A, b = 9,4550(5) A, c = 11,4592(4) A, V = 1344,69 A3, R1 = 0,0621, wR2 = 0,0926, 1497 beobachtete Reflexe mit I > 2σ(I)) enthalten verzerrte CoO6-Oktaeder bzw. quadratische ZnO5-Pyramiden, die uber gemeinsame Sauerstoff-Ecken mit BO4-, PO4- und (HO)PO3-Tetraedern verknupft sind. Die Tetraedergruppen bilden durch Kondensation uber gemeinsame Ecken unendliche, zyklisch verzweigte Borophosphat-Ketten [B2P3O12(OH)4–]. Die insgesamt offene Geruststruktur aus MII-Koordinationspolyedern und Borophosphat-Ketten ist von einem dreidimensionalen System unterschiedlicher Struktur-Kanale durchzogen, die entlang [100] bzw. [011] und [011] verlaufen und mit zweifach protonierten Piperazinium-Ionen besetzt sind.

(Ni3-xMgx)[B3P3O12(OH)6] · 6 H2O (x ≈ 1.5): A Novel BorophosphateHydrate Containing Isolated Six-Membered Rings of Tetrahedra

A novel borophosphate-hydrate, (Ni3–xMgx)[B3P3O12(OH)6] · 6 H2O (x ≈ 1.5), has been prepared by hydrothermal synthesis (T = 170 °C) from a mixture of NiCl2 · 6 H2O, Mg(OH)2, B2O3 and H3PO4. The crystal structure was determined at 293 K from single-crystal X-ray diffraction data (trigonal, R3c (no. 167), a = 14.957(10) A, c = 13.812(6) A, V = 2676(2) A3, Z = 6, R1 = 0.0276, wR2 = 0.0714 for 779 observed reflections with I > 2σ(I)). The crystal structure contains unbranched six-membered rings [B3P3O12(OH)6]6– of alternating corner linked borate and phosphate tetrahedra, which are stacked along [001] and connected via MIIO2(OH)2(H2O)2 coordination polyhedra. Hydrogen bonding between the tetrahedral six-membered rings and MIIO2(OH)2(H2O)2 octahedra leads to a further cross-linking. With respect to the arrangement of isolated six-membered tetrahedral rings the crystal structure of this borophosphate-hydrate is closely related to the cyclo-hexasilicate dioptase, Cu6[Si6O18] · 6 H2O. (Ni3–xMgx)[B3P3O12(OH)6] · 6 H2O (x ≈ 1.5): Ein neues Borophosphat-Hydrat mit isolierten Tetraeder-Sechserringen Ein neues Borophosphat-Hydrat, (Ni3-xMgx)[B3P3O12(OH)6] · 6 H2O (x ≈ 1.5), wurde unter milden hydrothermalen Bedingungen (T = 170 °C) aus einer Mischung von NiCl2 · 6 H2O, Mg(OH)2, B2O3 und H3PO4 dargestellt. Die Kristallstruktur wurde bei T = 293 K mit Rontgen-Einkristallmethoden bestimmt (trigonal, R3c (Nr. 167), a = 14.957(10) A, c = 13.812(6) A, V = 2676(2) A3, Z = 6, R1 = 0.0276, wR2 = 0.0714 fur 779 beobachtete Reflexe mit I > 2σ(I)). Die Kristallstruktur wird von isolierten sechsgliedrigen [B3P3O12(OH)6]6–-Ringen aus alternierend eckenverknupften Borat- und Phosphat-Tetraedern aufgebaut, die entlang [001] gestapelt sind und uber MIIO2(OH)2(H2O)2-Koordinations-Polyeder verknupft werden. Zusatzliche Verknupfungen ergeben sich durch Wasserstoffbruckenbindungen zwischen den sechsgliedrigen Tetraederringen und den MIIO2(OH)2(H2O)2-Oktaedern. Die Kristallstruktur des Borophosphats ist bezuglich der Anordnung der sechsgliedrigen Ringe aus eckenverknupften Tetraedern eng verwandt mit dem cyclo-Hexasilicat Dioptas, Cu6[Si6O18] · 6 H2O.