scholarly journals The Structural Dimorphism of Lanthanum Oxide Fluoride Selenide La2OF2Se

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 435 ◽  
Author(s):  
Buyer ◽  
Grossholz ◽  
Schleid
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Lanthanum Oxide ◽  
Solid State Reactions ◽  
Space Group ◽  
Molar Ratios ◽  
Type Form ◽  
Close Relationship ◽  
Lamellar Crystals

The new colorless lanthanum oxide fluoride selenide La2OF2Se could be synthesized via solid-state reactions in two different structure types. Lamellar crystals of A-La2OF2Se were obtained from mixtures of La, LaF3, La2O3 and Se in molar ratios of 2:2:1:3 with NaCl as flux for seven days in silica-protected sealed tantalum capsules at 850 °C. Needle-shaped crystals of BLa2OF2Se emerged from reactions of the same educt mixtures in molar ratios of 6:4:4:9 scheduled to produce La6O4F4Se3 with CsI as flux for four days in niobium ampoules at 700 °C. The Atype form of La2OF2Se crystallizes in the trigonal space group R3m with a = 418.13(3) and c = 4478.2(4) pm for Z = 6, whereas the Btype form is hexagonal (space group: P63/m) with a = 1396.82(9) and c = 401.08(3) pm for Z = 6. The crystal structure of A-La2OF2Se shows a close relationship to the fluoride-free La2O2Se and the oxygen-free La2F4Se. It can even be discussed as 1:1 intergrowth variety, since it contains the [LaO4Se3]11− and [LaF7Se3]10− polyhedra typical for the ternaries. B-La2OF2Se appears to be structurally very similar to La6O2F8Se3 in displaying [LaO3FSe4]12− and [LaOF6Se2]9− polyhedra. With 6.039 versus 6.036 g/cm³ the B-type form of La2OF2Se is slightly denser than the A-type variant.

Zum Mineral Johillerit verwandte Oxovanadate RbCd4V3O12 und TlCd4V3O12 / Oxovanadates RbCd4V3O12 and TlCd4V3 O12 Related to the Mineral Johillerite

1997 ◽  
Vol 52 (5) ◽  
pp. 663-668 ◽  
Author(s):  
B. Mertens ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystals ◽  
Solid State Reactions ◽  
Space Group ◽  
Related Compounds

Abstract Single crystals of I RbCd4V3O12 and TlCd4V3O12 II have been prepared by solid state reactions in closed iron tubes. The compounds crystallize closely related to the Johillerite structure in the space group C62h- C2/c with I: a = 13.058(3); b - 13.528(3), c = 7 .0 6 0 (2 )Å , β = 114.88(2)°; II: a = 12.999(6), b = 13.527(7), c = 7.055(3) Å , β = 114.88(4)°, Z = 4. Special features are the loss of Cu2+ in order to gain an additional Cd2+ position. The crystal structure is discussed with respect to related compounds of the Johillerite type.

scholarly journals Crystal structure of KNaCuP2O7, a new member of the diphosphate family

2018 ◽  
Vol 74 (2) ◽  
pp. 109-112 ◽  
Author(s):  
Ines Fitouri ◽  
Habib Boughzala
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Charge Distribution ◽  
Structural Model ◽  
Interlayer Space ◽  
Structure Type ◽  
Solid State Reactions ◽  
Space Group ◽  
Potassium Sodium ◽  
Bond Valence Sum

Potassium sodium copper(II) diphosphate(V), KNaCuP2O7, was synthesized by solid-state reactions. It crystallizes in the α-Na2CuP2O7 structure type in space group P21/n. In the crystal, CuO5 square-pyramids are linked to nearly eclipsed P2O7 groups by sharing corners to build up corrugated layers with composition [CuP2O7]2− that extend parallel to (010). The K+ and Na+ cations reside in the interlayer space and are connected to nine and seven O atoms, respectively. The structural model was validated by bond-valence-sum (BVS) and charge-distribution (CHARDI) analysis.

Ein Cadmium-Kupfer-Phosphat mit einfach überkappten trigonalen CdO6-Prismen-Netzen: Cd1.35Cu1.65(PO4)2

1996 ◽  
Vol 51 (2) ◽  
pp. 229-232 ◽  
Author(s):  
S. Münchau ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Melting Point ◽  
Single Crystals ◽  
Solid State Reactions ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
Symmetry Space ◽  
Light Green ◽  
Symmetry Space Group

Abstract Single crystals of Cd1.35Cu1.65(PO4)2 have been prepared by solid state reactions below the melting point of the starting compounds. The light green crystals crystallize with monoclinic symmetry, space group C52h-P21/c , a = 9.062(2), b = 11.669(2), c = 5.950(2) Å , β = 97.88(2)°, Z = 4. Cd1.35Cu1.65(PO4)2 shows relationship to the mineral graftonite. The crystal structure is characterized by nets of corner connected Cd2O12 polyhedra. One point position is statistically occupied by Cd2+ and Cu2+ ions.

scholarly journals Crystal structure of CsCrAs2O7, a new member of the diarsenate family

2015 ◽  
Vol 71 (6) ◽  
pp. 636-639 ◽  
Author(s):  
Mohamad Alem Bouhassine ◽  
Habib Boughzala
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Alkali Metal ◽  
Three Dimensional ◽  
Solid State Reactions ◽  
Type I ◽  
Space Group ◽  
P Type ◽  
Anionic Framework

Caesium chromium(III) diarsenate(V), CsCrAs2O7, was prepared by solid-state reactions. The title structure consists of isolated CrO6octahedra and As2O7diarsenate groups, sharing corners to build up a three-dimensional [CrAs2O7]−anionic framework. In this framework, channels extending parallel to [001] are present in which the ten-coordinate Cs+ions reside. CsCrAs2O7is isotypic with the monoclinicAIMIIIX2O7(AI= alkali metal;MIII= Al, Cr, Fe;X= As, P) type I family of compounds crystallizing in the space groupP21/c.

Isolierte MnCl6-Oktaeder im Oxohalogeno-Vanadat Ba5(Mg0,4Mn0,6)(V2O7)2MnCl6 / Isolated MnCl6 Octahedra in the Oxohalogeno Vanadate Ba5(Mg0,4Mn0,6)(V2O7)2MnCl6

1997 ◽  
Vol 52 (4) ◽  
pp. 457-461 ◽  
Author(s):  
R. Rettich ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Melting Point ◽  
Vanadium Oxide ◽  
Single Crystals ◽  
Solid State Reactions ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of Ba5(Mg0,4Mn0,6)(V207)2MnCl6 have been prepared by solid state reactions of MgCO3, Mn2O3, V2O5 and BaCl2·2H2O below the melting point of BaCl2. The new vanadium oxide chloride crystallizeswith monoclinic symmetry, space group C42h-P2/c, a = 13.345(4), b = 5.711(2), c = 15.859(4) Å, β = 113.69(2)°, Z = 2. Special features of the crystal structure are isolated MnCl6 octahedra and layers created by divanadat groups and (Mg,Mn)O6 octahedra. The 2∞ [(Mg,Mn)V2O7] nets of Ba3(Mg0,4Mn0,6)(V2O7)2MnCl6 are discussed with respect to other oxohalogeno vanadates Containing divanadate groups.

scholarly journals Crystal structure of calcium dinickel(II) iron(III) tris(orthophosphate): CaNi2Fe(PO4)3

2017 ◽  
Vol 73 (6) ◽  
pp. 893-895
Author(s):  
Said Ouaatta ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Title Compound ◽  
Linear Chain ◽  
Three Dimensional ◽  
Solid State Reactions ◽  
Common Edge ◽  
Space Group ◽  
Infinite Linear

The title compound, CaNi2Fe(PO4)3, was synthesized by solid-state reactions. Its structure is closely related to that of α-CrPO4in the space groupImma. Except for two O atoms in general positions, all atoms are located in special positions. The three-dimensional framework is built up from two types of sheets extending parallel to (100). The first sheet is made up from two edge-sharing [NiO6] octahedra, leading to the formation of [Ni2O10] double octahedra that are connected to two PO4tetrahedra through a common edge and corners. The second sheet results from rows of corner-sharing [FeO6] octahedra and PO4tetrahedra forming an infinite linear chain. These layers are linked together through common corners of PO4tetrahedra and [FeO6] octahedra, resulting in an open three-dimensional framework that delimits two types of channels parallel to [100] and [010] in which the eightfold-coordinated CaIIcations are located.

Ba(VO)4(AsO4)2(As2O7): Ein neues Divanadyl(IV)-Arsenat mit flächenverknüpften V2O8+1-Oktaederdoppeln / Ba(VO)4 (AsO4)2 (As2O7): A New Divanadyl(IV)-Arsenate Containing Face Shared V2O8+, Double Octahedra

1997 ◽  
Vol 52 (1) ◽  
pp. 83-87 ◽  
Author(s):  
C. Wadewitz ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Alkaline Earth ◽  
Solid State Reactions ◽  
Orthorhombic Symmetry ◽  
Space Group ◽  
X Ray ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

A new alkaline earth vanadyl arsenate Ba(VO)4(AsO4)2(As2O7) has been synthesized by solid state reactions in closed quartz tubes. X-ray investigations led to orthorhombic symmetry, space group D162h-Pnma, α = 17.540(2), b = 7.6223(8), c = 11.0633(12) Å, Z = 4. The crystal structure is characterized by AsO4 single and As2O7 double tetrahedra and face shared asymmetric stretched V2O8+1, double octahedra, forming a network of polyhedra. The incorporated Ba2+ ions show 12-fold coordination by oxygen. Ba(VO)4(AsO4)2(As2O7) is the first vanadyl compound containing V2O8 divanadyl groups originating from face sharing stretched VO5+1 octahedra

Cd0,73Cu0,27V2O6: Eine Verbindung mit Branneritstruktur / Cd0 ,73Cu0,27V2O6: A Compound with Brannerite Structure

1994 ◽  
Vol 49 (7) ◽  
pp. 927-930 ◽  
Author(s):  
S. Münchau ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystals ◽  
Solid State Reactions ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
X Ray ◽  
Jahn Teller ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of Cd0.73Cu0.27V2O6 were prepared by solid state reactions. X-ray investigations lead to monoclinic symmetry, space group C32h-C2/m , a = 9.339, b = 3.5604, c = 6.893 Å, β = 111.85°, Z = 2. It belongs to the Brannerite structure, showing a statistical distribution of Cd2+ and Cu2+ on one point position. The crystal structure of Brannerites is discussed with respect to the distorted O2- octahedra around V5+ and the influence of the Jahn-Teller active Cu2+ ion to the shortened M2+O6 octahedra.

Syntheses and vibrational spectra of some tris(alkanethiolato)mercurate(II) complexes, and crystal structure of the Hexakis(methanethiolato)dimercurate(II) dianion

1984 ◽  
Vol 37 (8) ◽  
pp. 1607 ◽  
Author(s):  
GA Bowmaker ◽  
IG Dance ◽  
BC Dobson ◽  
DA Rogers
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Vibrational Spectra ◽  
Crystal Data ◽  
Tetrahedral Geometry ◽  
Space Group ◽  
Spectroscopic Evidence ◽  
Distorted Tetrahedral Geometry ◽  
Complex Anions

The complexes [cation] [Hg(SR)3](R = Me, cation = Et4N+; R = But, cation = Et4N+, Bu4N+, [N(Ph3P)2]+) have been prepared. The crystal structure of the methanethiolate complex shows that it contains centrosymmetric dinuclear anions [(MeS)2Hg(�-SMe)2Hg(SMe)2]2- with distorted tetrahedral geometry about the mercury atoms. Vibrational spectroscopic evidence suggests that this complex dissociates on dissolution in ethanol to give mononuclear [Hg(SMe)3]- species. The ButS- complexes appear to exist as mononuclear [Hg(SBut)3]- species both in the solid state and in solution. The metal-sulfur stretching frequencies are assigned for all of the complexes studied, and the vibrational spectra are discussed in terms of the structures of the complex anions involved. Crystal data for [(C2H5)4N]2Hg2(SCH3)6 : a 8.656(5), b gS130(6), c 12.368(8) �; α 102.16(4), β 105.51(4), γ 105.29(4)�; space group P1, Z 1, R 0.034, Rw 0.042.

scholarly journals Zur Kenntnis eines Barium-Oxoniobat-Tellurats: Ba2Nb2TeO10 / On a Barium-Oxoniobate-Tellurate: Ba2Nb2TeO10

1996 ◽  
Vol 51 (10) ◽  
pp. 1407-1410 ◽  
Author(s):  
B. Wedel ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystals ◽  
Solid State Reactions ◽  
Orthorhombic Symmetry ◽  
X Ray ◽  
Lattice Constants ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of Ba2Nb2TeO10) have been prepared by solid state reactions in air. X-ray investigations led to orthorhombic symmetry, space group D152h-Pbca, a = 7.242(4), b = 12.433(3), c = 9.932(3) Å. Z = 4. Nb5+ and Te6+ show octahedral coordination by O2- . The crystal structure is characterized by planes of edge- and corner-sharing NbO6- and TeO6octahedra. It is shown that in spite of nearly identical lattice constants of Ba2Nb2TeO10 with compounds of the composition M0,5BaNbTe2O9 the so far unknown crystals of these substances may not be derived from the Ba2Nb2TeO10 type.

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