Bromoselenate(II): Darstellung, Struktur und Eigenschaften von [P(C6H5)4]2SeBr4 und [P(C6H5)4]2Se2Br6 / Bromoselenates(II): Preparation, Structure and Properties of [P(C6H5)4]2SeBr4 and [P(C6H5)4]2Se2Br6

1984 ◽  
Vol 39 (12) ◽  
pp. 1633-1641 ◽  
Author(s):  
Bernt Krebs ◽  
Andreas Schäffer ◽  
Siegfried Pohl
Keyword(s):  
Bond Length ◽  
Vibrational Spectra ◽  
Acetonitrile Solution ◽  
The Novel ◽  
Structure And Properties ◽  
Subsequent Reaction ◽  
Space Group ◽  
X Ray ◽  
Square Planar ◽  
The Mean

The novel anion SeBr42- was prepared by dissociation of SeOBr2 with formation of SeBr2 and subsequent reaction with bromide in acetonitrile solution; it was isolated as the crystalline tetraphenylphosphonium salt. The X-ray structure analysis of [P(C6H 5)4]2SeBr4 (space group P 1̄ , a = 14.190(3), b = 15.125(3), c = 10.383(2) Å , α = 92.69(2), β = 100.89(2), γ = 92.04(2)° Å , V = 2182.2 Å3) shows the structure to contain monomeric SeBr42- anions with a square planar coordination of Se(II). The mean Se -Br bond length in the anion is 2.598 Å .[P(C6H5)4]2Se2Br6 was obtained from the reaction of SeBr4 (which is in equilibrium with SeBr2, Se2Br2, and Br2, in solution) and bromide in acetonitrile. It crystallizes in the space group P 1̄, with a = 1 0 . 9 3 3 ( 4 ) , = 11.154(4), c = 10.344(4) Å , α = 79.26(3), β = 72.63(3), y = 81.35(3)°, γ = 1176.7 Å3 (at -120 °C), and contains a novel type of centrosymmetric Se2Br62- ions with square planar Se-coordination. The mean terminal and bridging Se -Br bond lengths are 2.442 and 2.799 Å , resp. Vibrational spectra are reported and discussed.

Tetrahalogenotellurate(II): Synthese und Kristallstrukturen von Verbindungen mit den Ionen TeX42- (X = Cl, Br, I)/Tetrahalotellurates(II): Syntheses and Crystal Structures of Compounds with TeX42- Ions (X = Cl, Br, I)

1985 ◽  
Vol 40 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Bernt Krebs
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Acetonitrile Solution ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Square Planar

Abstract The compounds [(C6H5)4As]2 TeCl4 (1), [(C2H5)4 N]2 TeBr4 · CH3CN (2), and [(C2H5)4N]2TeI4 (3) were prepared by the reaction of Te, X2 , and excess (C2H5)4NX (X = Br, I) in acetonitrile solution or by heating of [(C6H5)4 As]2TeCl6 , Te, and (C6H5)4 ASCl for several hours in the same solvent.The structures of 1-3 were determined from single crystal X-ray data.1 crystallizes in the monoclinic space group P21/n with a = 1061.8(2), b = 1614.2(3), c = 1341.7(3) pm, β = 94.21° and Z = 2; 2: tetragonal, P4/mmm, a = 1039.7(2), c = 690.5(1), Z = 1; 3: tetragonal, I4/mmm, a = 1061.7(2), c = 1342.8(4), Z = 2. In 1-3 Te(II) exhibits a square planar coordination. The Te -CI, Te -Br, and Te-I bond lengths were found to be 260.7 (mean), 275.3, and 298.5 pm, respectively.

Synthese, Struktur und Eigenschaften der Nonachloroditellur(IV)- und Tetrachlorohydroxotellur(IV)säure-Hydrate. Kristallstrukturen der Oxonium-Salze [H9O4]n[Te2Cl9]n und [H9O4][TeCl4OH ] · H2O/Synthesis, Structure and Properties of Nonachloroditellurous and Tetrachlorohydroxotellurous Acid Hydrates. Crystal Structures of the Oxonium Salts [H9O4]n[Te2Cl9]n und [H9O4][TeCl4OH ] · H2O

1992 ◽  
Vol 47 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Bernt Krebs ◽  
Stefan Bonmann ◽  
Klaus Gretenkord
Keyword(s):  
Crystal Structures ◽  
Raman Spectra ◽  
The Novel ◽  
Structure And Properties ◽  
Apical Position ◽  
Space Group ◽  
Light Yellow ◽  
Distorted Octahedral ◽  
The Mean ◽  
Polymeric Anion

Light yellow needles of crystalline nonachloroditellurous acid with the formal composition HTe2Cl9 · 4H2O (1) (space group C2/c, a = 11.642(6), b = 13.012(4), c = 12.663(5) Å, β = 119.64(3)° at 140 K) were isolated from a saturated solution of TeCl4 in conc. HCl. From a solution of more diluted HCl the acid HTeCl4OH · 5H2O (2) could be prepared (space group P212121, a = 7.065(3), b = 8.551(2), c = 18.192(6)Å at 140 K). 1 is the first acid isolated from the system TeCl4 /HCl/H2O with a polymeric anion. The novel polynuclear [Te2Cl9]nn- chains are built from alternately corner-sharing and edge-sharing distorted octahedral TeCl6 units. The mean bond distances are 2.356 Å for terminal Te-Cl and 2.805 Å for Te-μ2Cl. 2 contains square-pyramidal [TeCl4OH]- anions with oxygen in the apical position (Te-Cl: 2.447-2.552 Å; Te-O: 1.926 Å). The cations in both structures are [H9O4]+ hydroxonium ions (O···O (1): 2.47(3), 2.55(2) and 2.57(1) Å; O···O (2): 2.550(4), 2.584(4) and 2.588(5) Å). Thus the formulae of the acids have to be written as [H9O4]n[Te2Cl9]n and [H9O4][TeCl4OH] · H2O. Raman spectra of both compounds are reported.

Oxotrihalogenoselenate(IV): Darstellung, Struktur und Eigenschaften von P(C6H5)4SeOCl3, P(C6H5)4SeOBr3 und As(C6H5)4SeOBr3

1982 ◽  
Vol 37 (11) ◽  
pp. 1410-1417 ◽  
Author(s):  
Bernt Krebs ◽  
Andreas Schaffer ◽  
Marita Hucke
Keyword(s):  
Crystalline Form ◽  
Acetonitrile Solution ◽  
The Novel ◽  
Space Group ◽  
X Ray

The novel oxotribromosolcnate(IV) SeOBr3- anion was prepared from the reaction of stoichiometric quantities of SeOBr2 and bromide in acetonitrile solution, and it was isolated as the tetraphenylphosphonium and -arsonium salts in crystalline form. For the synthesis of the analogous SeOCl3- as P(C6H5)4SeOCl3, SeCl4 was reacted in the presence of a small quantity of H2O with P(C6H5)4Cl in acetonitrile. Complete X-ray structural analyses of P(C6H5)4SeOCl3 (space group P1̄, a = 10.981(3), b = 11.0511(3), c = 10.358(3) Å, α = 73.77(2)°, β = 83.33(2)°, γ = 80.51(2)°, V = 1187.9(6) Å3) and of P(C6H5)4SeOBr3 (space group P 21/c, a = 11.719(4), b = 16.088(4), c = 13.124(4) Å, β = 94.72(3)°, V = 2400(1) Å3) show dimeric centrosymmetric Se2O2Cl62- and Se2O2Br62- anions being present in the solid. In the anions two square-pyramidal (Ψ-octahedral) SeOHal4 groups are connected through a common Hal-Hal edge. The axial oxygen ligands (So-O: 1.597(4) and 1.584(0) Å) cause a pronounced stereochemical trans-activation of the inert pairs at the Se atoms. As(C6H5)4SeOBr3 is isotypic with P(C6H5)4SeOCl3.

Synthese, Struktur und Eigenschaften der Hexabromotellur(IV)- und Tridekabromotritellur(IV)säure-Hydrate. Kristallstrukturen der Oxonium-Salze [H9O4]2[TeBr6] und [H9O4][Te3Br13] / Synthesis, Structure and Properties of Hexabromotellurous and Tridecabromotritellurous Acid Hydrates. Crystal Structures of the Oxonium Salts [H9O4]2[TeBr6] and [H9O4][Te3Br13]

1991 ◽  
Vol 46 (7) ◽  
pp. 919-930 ◽  
Author(s):  
Bernt Krebs ◽  
Stefan Bonmann ◽  
Klemens Erpenstein
Keyword(s):  
Concentration Ratio ◽  
Stoichiometric Composition ◽  
Structural Formula ◽  
Structure And Properties ◽  
Space Group ◽  
X Ray ◽  
Edge Sharing Octahedra ◽  
Hydrogen Bond System ◽  
Bond System ◽  
The Mean

From solutions of TeBr4 in concentrated aqueous HBr red needles of the crystalline hexabromotellurous acid with the stoichiometric composition H2TeBr6 · 8H2O (1) were isolated (space group P21/n, a = 7.662(5), b = 9.796(6), c = 11.987(8) Å, β = 91.35(4)° at 259 Κ). If the HBr:TeBr4 concentration ratio in the system TeBr4/HBr/H2O was kept low, a novel acid with formal composition HTe3Br13 ·4 H2O (2) could be prepared (space group Cm, a = 13.501(5), b = 15.453(6), c = 9.153(3) Å, β = 138.11(2)° at 140 Κ). The X-ray structural analysis of 1 shows the acid to contain, besides regular octahedral [TeBr6]2- ions (Te-Br: 2.671(4)-2.716(4) Å), [Η9Ο4]+ hydroxonium ions (O ··· O: 2.48(3)-2.62(3) Å). The [H9O4]+ units are linked through a hydrogen bond system (O ··· O: 2.80(3)-2.97(4) Å) to form a three-dimen-sional network. The formula has to be written as [H9O4]2[TeBr6]. 2 is the first acid in this class with a trinuclear anion. Its structural formula is [H9O4][Te3Br13]. As a fragment of the Te4Br,6 cube the anion consists of three edge-sharing octahedra with a central triply bridging Br. The mean bond distances are 2.515 Å for terminal Te-Br, 2.944 Å for Te-μ2Br and 3.077 Å for Te—μ3Br. The Ο···Ο distances in the isolated [H9O4]+ hydroxonium ions are 2.45(3)-2.57(2) A. Raman spectra of both acids are reported.

Synthesis and characterization of [M(DMSO)6][SnCl6] complexes (M = Fe2+, Co2+, and Ni2+) — An old mystery solved

2007 ◽  
Vol 85 (5) ◽  
pp. 372-378 ◽  
Author(s):  
Andrew P White ◽  
Katherine N Robertson ◽  
T Stanley Cameron ◽  
Bernard V Liengme ◽  
Daniel B Leznoff ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Bond Length ◽  
Mossbauer Spectroscopy ◽  
Complex Salt ◽  
The Novel ◽  
Complex Ions ◽  
Double Complex ◽  
Space Group ◽  
X Ray ◽  
Mößbauer Spectroscopy

The synthesis of an "unknown" Fe(II) complex originally reported in 1973 and formulated then as [Fe(DMSO)5Cl][SnCl4] was thoroughly reproduced and the compound reformulated as the novel [Fe(DMSO)6][SnCl6] double complex salt. Current elemental analysis and IR and Mössbauer spectroscopy matched the original 1973 data, and Raman spectroscopy and single crystal X-ray diffraction provided additional confirmation of our reformulation. [Fe(DMSO)6][SnCl6] (1) crystallizes in the trigonal space group R[Formula: see text] with octahedral [Fe(DMSO)6]2+ and [SnCl6]2– complex ions with an Fe—O bond length of 2.121(3) Å. The same synthesis was extended to Co(II) and Ni(II) to generate the novel [Co(DMSO)6][SnCl6] (2), which crystallizes in the triclinic space group P[Formula: see text] with a Co—O bond length of 2.093(4)–2.113(5) Å, and [Ni(DMSO)6][SnCl6] (3), which crystallized in the trigonal R[Formula: see text] space group and has a Ni—O bond length of 2.062(2) Å. The Sn—Cl bond length in all three complexes ranged from 2.421(2) to 2.448(2) Å.Key words: DMSO complexes of Fe(II), Co(II) and Ni(II), SnCl62– salts, IR, Raman and Mössbauer spectroscopy, X-ray crystal structures.

Inclusion compounds of plant growth regulators in cyclodextrins. V. 4-Chlorophenoxyacetic acid encapsulated in β-cyclodextrin and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin

2005 ◽  
Vol 61 (2) ◽  
pp. 207-217 ◽  
Author(s):  
Frantzeska Tsorteki ◽  
Kostas Bethanis ◽  
Nikos Pinotsis ◽  
Petros Giastas ◽  
Dimitris Mentzafos
Keyword(s):  
Guest Molecule ◽  
Crystal Packing ◽  
Host Molecule ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
Space Group ◽  
X Ray ◽  
Dimeric Complexes ◽  
The Mean ◽  
Chlorophenoxyacetic Acid

The crystal structures of 4-chlorophenoxyacetic acid (4CPA) included in β-cyclodextrin (β-CD) and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TMβCD) have been studied by X-ray diffraction. The 4CPA/β-CD complex crystallizes as a head-to-head dimer in the space group C2 in the Tetrad packing mode. The packing modes of some β-CD dimeric complexes, having unique stackings, are also discussed. The 4CPA/TMβCD inclusion complex crystallizes in the space group P21 and its asymmetric unit contains two crystallographically independent complexes, complex A and complex B, exhibiting different conformations. The host molecule of complex A is significantly distorted, as a glucosidic residue rotated about the O4′—C1 and C4—O4 bonds forms an aperture where the guest molecule is accommodated. The phenyl moiety of the guest molecule of complex B is nearly perpendicular to the mean plane of the O4n atoms. The conformations of the guest molecules of the two complexes are similar. The crystal packing consists of antiparallel columns as in the majority of the TMβCD complexes published so far.

Nitrido-und Oxochlorokomplexe des Vanadiums(V); die Kristallstruktur von AsPh4 [V0C14] Nitrido and Oxochloro Complexes of Vanadium(V); the Crystal Structure of AsPh4[VOCl4]

1980 ◽  
Vol 35 (5) ◽  
pp. 522-525 ◽  
Author(s):  
Gisela Beindorf ◽  
Joachim Strähle ◽  
Wolfgang Liebelt ◽  
Kurt Dehnicke
Keyword(s):  
Crystal Structure ◽  
Ir Spectra ◽  
Bond Length ◽  
Bond Angle ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Linear Arrangement ◽  
Space Group ◽  
X Ray ◽  
Complex Anions

The complexes AsPh4[Cl4V = N-Cl] and AsPh4[VOCl4] are prepared by the reaction of AsPh4Cl with Cl3VNCl and VOCl3, respectively. The IR spectra indicate C4v symmetry for the complex anions with multiple VN and VO bonds and a linear arrangement for the VNCl-group. AsPh4[VOCl4] crystallizes in the tetragonal space group P4/n with two formula units in the unit cell. The crystal structure was solved by X-ray diffraction methods (R = 0,062, 1096 observed, independent reflexions). The structure consists of AsPh4+ cations and [VOCl4]- anions with symmetry C4v. The extremely short VO bond length corresponds with a VO triple; its steric requirements cause the relatively large bond angle OVCl of 103.4°.

Centrosymmetric or Noncentrosymmetric? Case Study, Generalization and Structural Redetermination of Sr5Nb5O17

1998 ◽  
Vol 54 (4) ◽  
pp. 399-416 ◽  
Author(s):  
S. C. Abrahams ◽  
H. W. Schmalle ◽  
T. Williams ◽  
A. Reller ◽  
F. Lichtenberg ◽  
...  
Keyword(s):  
Niobium Oxide ◽  
The Novel ◽  
Physical Measurement ◽  
X Ray Diffraction ◽  
Acta Cryst ◽  
Data Set ◽  
Space Group ◽  
X Ray ◽  
Atomic Coordinates

The possibility that the structure of the novel semiconducting perovskite-related material strontium niobium oxide, Sr5Nb5O17, refined by Schmalle et al. [Acta Cryst. (1995), C51, 1243–1246] in space group Pnn2, might instead belong to space group Pnnm has been investigated following an analysis of the atomic coordinates that indicated the latter space group to be more likely. All I obs were carefully remeasured, first those within a hemisphere containing c *, then all that lay within the full sphere of reflection. Refinement was undertaken, with each of two different sets of weights, in each space group. Each data set was used under three limiting intensity conditions: I obs > 4σ(I obs), I obs > 2σ(I obs) and finally with all reflections, but setting magnitudes with I obs ≤ 0 equal to 0. Fourteen separate tests based only upon the X-ray diffraction data may be used to distinguish between Pnn2 and Pnnm. Nine tests favored the latter choice, four were indeterminate and one was not used. Seven further tests may be made on the basis of physical measurement; of these, three strongly indicated Pnnm, one was indeterminate and three could not be used. The evidence clearly suggests the space group is Pnnm. The use of all reflections, including those with negative magnitude set equal to zero, is essential to avoid ambiguity in the X-ray diffraction tests and achieve the highest reliability. Refinement with weights based on variances of Type A and Type B [Schwarzenbach et al. (1995). Acta Cryst. A51, 565–569] resulted in improved reliability compared with that obtained from a popular empirical weighting scheme. The revised structure differs in several respects from that published previously.

scholarly journals Die Kristallstruktur des Silbertetrachloroaurats(III) AgAuCl4 und seine kristallchemische Verwandtschaft zum Rubidiumtetrachloroaurat(III) RbAuCl4 / The Crystal Structure of Silver Tetrachloroaurate(III) AgAuCl4 and its Crystal Chemical Relationship to the Rubidium Tetrachloroaurate(III) RbAuCl4

1977 ◽  
Vol 32 (7) ◽  
pp. 741-744 ◽  
Author(s):  
Walther Werner ◽  
Joachim Strähle
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Octahedral Coordination ◽  
Monoclinic Space Group ◽  
Crystal Chemical ◽  
Space Group ◽  
Square Planar ◽  
Cl Atoms

AgAuCl4 crystallizes in the monoclinic space group I2/c with Zi = 4. The crystal structure is built up by Ag+ cations and square planar AuCl4⁻ anions with Au-Cl bond length of 228 pm. The Ag+ ions have an octahedral coordination of Cl atoms. AgAuCl4 is topologically related to RbAuCl4.

The Crystal and Molecular Structures of Bis(diethyldithiocarbamato)platinum(II) and Bis[di(2-hydroxyethyl)dithiocarbamato]platinum(II)

1992 ◽  
Vol 45 (2) ◽  
pp. 429 ◽  
Author(s):  
AT Baker ◽  
MT Emett
Keyword(s):  
Single Crystal ◽  
Bond Length ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Crystal And Molecular Structures

The structures of [Pt(S2CN(C2H5)2)2] (1) and [Pt(S2CN(C2H4OH)2)2] (2) have been determined by single-crystal X-ray diffractometry. Compound (1) crystallizes in the tetragonal space group P42/n, a 16.4692(10),c 6.2160(6) � (Z = 4); R was 0.029 for 1012 observed reflections. Compound (2) is monoclinic, space group Pc, a 6-0663(11), b 1.1784(15), c 12.5740(21) � ,β92.569(8)� (Z = 2); R was 0.019 for 1573 observed reflections. The presence of electron-withdrawing groups in the ligands of (2) appears to have little effect on the Pt-S distances but causes an increase in the C-N bond length, with the C-N bond lengths being significantly different at the 2 σ level.

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