Polyhedral characteristics of the cosalite-type crystal structures

2019 ◽  
Vol 57 (5) ◽  
pp. 647-662
Author(s):  
Sabina Kovač ◽  
Predrag Dabić ◽  
Aleksandar Kremenović ◽  
Aleksandar Pačevski ◽  
Ljiiljana Karanović ◽  
...  

Abstract The crystal structure of cosalite from the Trepča orefield was refined in the orthorhombic space group Pnma [a = 23.7878 (9), b = 4.0566 (3), c = 19.1026 (8) Å, V = 1843.35 (17) Å3, Z = 2] from single-crystal data (MoKα X-ray diffraction, CCD area detector) to the conventional R1 factor 0.031 for 1516 unique reflections with I > 2σ(I). The chemical formula (Cu0.15Ag0.24)+(Fe0.19Pb7.20)2+(Bi7.06Sb1.06)3+S20, calculated on the basis of 20 S atoms per formula unit, was determined by WDX. The unit cell contains 18 + 2 symmetrically nonequivalent atomic sites: 10 occupied by S; two by pure Pb (Pb3 and Pb4); one by pure Bi (Bi1); two by a combination of Bi and small amounts of Sb (Bi2/Sb2, Bi4/Sb3); two by Pb and Bi, and in one of these also by a small amount of Ag [Me1 = Pb2 >> Bi5 > Ag1, Me3 = Pb1 >> Bi3]; and finally one site, Me2 (Bi6 >> □), is partly occupied by Bi and partly split into an additional two adjacent trigonal planar “interstitial positions”, Cu1 and Cu2, where small amounts of Cu, Ag, and Fe can be situated. All atoms are at 4c special positions at y = 0.25 or 0.75. The structure consists of slightly to moderately distorted MeS6 octahedra sharing edges, bicapped trigonal PbS8 coordination prisms, and fairly distorted Cu1S6 and Cu2S4 polyhedra. The effects of the cation substitutions, bond valence sums, and the polyhedral characteristics are compared with other published cosalite-type structures. Among known cosalite-type structures, the largest volume contraction is shown by sample 4 (Altenberg) and involves the replacement of large cations (Bi3+ and Pb2+) by the smaller Sb3+, as well as Cu+ and Ag+. These replacements are reflected in the variations of individual Me–S bond distances, which are accompanied by variations in average Me–S distances. The degree of polyhedral distortion, Δ, progressively increases for the four Bi-hosting sites of nine cosalite-type structures: Me2 < Bi2 < Bi1 < Bi4. The Bi4 and Me3 are the most and the Me1 and Me2 are the least distorted octahedral sites of the nine cosalite-type structures.

1992 ◽  
Vol 47 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Anja Edelmann ◽  
Sally Brooker ◽  
Norbert Bertel ◽  
Mathias Noltemeyer ◽  
Herbert W. Roesky ◽  
...  

Abstract The Molecular Structures of [2,4,6-(CF3)3C6H2S]2 (1) [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2 (3) have been determined by X-ray diffraction. Crystal data: 1: orthorhombic, space group P212121, Z = 4, a = 822.3(2), b = 1029.2(2), c = 2526.6(5) pm (2343 observed independent reflexions, R = 0.042); 2: orthorhombic, space group Iba 2, Z = 8, a = 1546.5(2), b = 1578.4(2), c = 1483.9(1) pm (2051 observed independent reflexions, R = 0.030); 3: monoclinic, space group P 21/c, Z = 4, a = 1118.7(1), b = 1536.5(2), c = 1492.6(2) pm, β = 98.97(1)° (3033 observed independent reflexions, R = 0.025).


1985 ◽  
Vol 40 (12) ◽  
pp. 1631-1637 ◽  
Author(s):  
Ruth Christophersen ◽  
Paul Klingelhöfer ◽  
Ulrich Müller ◽  
Kurt Dehnicke

Abstract The pyridine complexes of cyclo-thiazeno vanadium dichloride, [VCl2(N3S2)py] and [VCl2(N3S2)(py)2] were synthesized by reactions of polymeric VCl2(N3S2) with varying amounts of pyridine in CH2Cl2. The compounds were characterized by their IR spectra as well as by their 51V NM R spectra. The crystal structure of [VCl2(N3S2)(C5H5N)] was determined by means of X-ray diffraction (1582 independent observed reflexions, R = 0.031). Crystal data: orthorhombic, space group Pnma, a = 1372, b - 2261, c - 1068 pm, Z = 12. In the lattice there are two monomeric, crystallographically independent molecules [VCl2(N3S2)(C5H5N)], which differ only slightly. The vanadium atoms have a trigonal bipyramidal coordination with the N atom of the pyridine molecule and one chlorine atom in apical positions, and with one chlorine atom and the N atoms of the cyclo-thiazeno ligand in equatorial positions. The VN bond lengths of the planar VN3S2 ring of 174 pm correspond to double bonds


2020 ◽  
Vol 11 (1) ◽  
pp. 1-5
Author(s):  
Alice Prudente Borges ◽  
Claudia Cristina Gatto ◽  
Victor Marcelo Deflon ◽  
Pedro Ivo Da Silva Maia

The binuclear oxidovanadium(V) complex [{VO(L)}2(μ-O)(μ-H2O)]∙2CH3CN (1), where L2– is the dianion of the Schiff base 2-salicylaldehyde-2-hydroxybenzoylhydrazone, were prepared and characterized by elemental analysis, FTIR, 1H, 13C and 51V NMR. Furthermore, the crystal structure of the compound 1 was determined by single crystal X-ray diffractometry revealing a distorted octahedral O5N-coordination geometry around the V(V) acceptor centers. The vanadium ions are connected by the μ-O2– and the μ-H2O asymmetric bridges located in the edge between the two octahedrons which keeps a distance of 3.194 Å between the two vanadium centers. Crystal data for C32H28N6O10V2 (M =758.48 g/mol): orthorhombic, space group P212121 (no. 19), a = 12.9655(8) Å, b = 14.1902(9) Å, c = 18.4379(10) Å, V = 3392.3(4) Å3, Z = 4, T = 293(2) K, μ(MoKα) = 0.616 mm-1, Dcalc = 1.485 g/cm3, 18803 reflections measured (3.622° ≤ 2Θ ≤ 56.704°), 8263 unique (Rint = 0.0473, Rsigma = 0.1020) which were used in all calculations. The final R1 was 0.0509 (I > 2σ(I)) and wR2 was 0.1531 (all data). The (VO)2(μ-O)(μ-H2O) core in compound 1 represents a rare case and few examples of similar type have been structurally characterized.


2019 ◽  
Vol 10 (4) ◽  
pp. 409-416 ◽  
Author(s):  
Shahobiddin Adizov ◽  
Bakhodir Tashkhodjaev

The single crystal X-ray diffraction method established the absolute configuration of the Vinca erecta indole alkaloids of the akuammidine sarpagine type (3S, 5S, 15R, 16R) and its o-acyl derivative, as well as the type of ajmaline, quebrachidine (2S, 3S, 5S, 7R, 15S, 16R, 17S) and majoridine (2R, 3S, 5S, 7R, 15R, 16S, 17R). Crystal data for C21H24N2O3 (1): orthorhombic, space group P212121 (no. 19), a = 6.3949(5) Å, b = 13.5009(10) Å, c = 22.461(3) Å, Z = 4, 7694 reflections measured (7.64° ≤ 2Θ ≤ 152.294°), 3813 unique (Rint = 0.0798) which were used in all calculations. The final R1 was 0.0680 (I > 2σ(I)) and wR2 was 0.1650 (all data). Crystal data for C23H26N2O4 (2): orthorhombic, space group P212121 (no. 19), a = 9.9730(13) Å, b = 10.2090(10) Å, c = 20.409(3) Å, Z = 4, 7959 reflections measured (8.666° ≤ 2Θ ≤ 151.998°), 4212 unique (Rint = 0.0386) which were used in all calculations. The final R1 was 0.0477 (I > 2σ(I)) and wR2 was 0.1171 (all data). Crystal data for C42H48N4O6 (3): monoclinic, space group P21 (no. 4), a = 8.9320(10) Å, b = 21.515(5) Å, c = 9.5420(10) Å, β = 97.103(10)°, Z = 2, 16677 reflections measured (9.34° ≤ 2Θ ≤ 151.836°), 7393 unique (Rint = 0.0278) which were used in all calculations. The final R1 was 0.0366 (I > 2σ(I)) and wR2 was 0.1037 (all data). Crystal data for C23H28N2O3 (4): orthorhombic, space group P212121 (no. 19), a = 10.636(2) Å, b = 11.208(12) Å, c = 16.725(13) Å, Z = 4, 1650 reflections measured (9.498° ≤ 2Θ ≤ 119.97°), 1650 unique (Rint = 0.0436) which were used in all calculations. The final R1 was 0.0608 (I > 2σ(I)) and wR2 was 0.1720 (all data). In alkaloids such as sarpagine and ajmaline exo, the substituents of alkaloids do not lead to conformational changes of a stable polycyclic framework. In the series of sarpagine, alkaloids form mono-salts in the tetrahedral nitrogen N4, and in indolines of the ajmaline type, the tetrahedral hybridization of the N1 and N4 atoms favors the formation of disols. In V. erecta alkaloids, the exomethylene fragment (C18-C19=C20-C21) of the polycyclic backbone always takes on the E-state.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
R. Kefi ◽  
M. Zeller ◽  
F. Lefebvre ◽  
C. Ben Nasr

The crystal structure of the new inorganic-organic hybrid compound [4-CH3C6H4CH2NH3]2[CdCl4] has been determined by single crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Pnma with lattice parameters a=10.721(2), b=33.986(6), c=5.326(1) Å, β=97.222(1)°, V=1940.8(7) Å3, and Z=4. The framework of the title compound is built upon layers parallel to (010) made up from corner-sharing CdCl6 octahedra. 4-Methylbenzylammonium cations are situated between the layers and connect them via an N–H⋯Cl hydrogen bonding network. The Cd atom is located on an inversion centre, and the coordination environment is described as distorted octahedral. Solid state 13C CP-MAS NMR spectroscopy is in agreement with the X-ray structure. DFT calculations allow the attribution of the carbon peaks to the independent crystallographic sites. Thermal analysis and infrared spectroscopy were also used to characterize the complex.


2004 ◽  
Vol 68 (4) ◽  
pp. 677-686 ◽  
Author(s):  
U. Kolitsch ◽  
E. Tillmanns

AbstractDuring investigations of the system Sc2O3-Al2O3-TiO2-SiO2, a new, unusual microporous compound, Cs3ScSi8O19, was synthesized as colourless plates from a CsF-MoO3 flux. The crystal structure was determined from single-crystal X-ray diffraction data (Mo-Kα radiation, CCD area detector). The compound is orthorhombic, space group Pnma, with a = 11.286(2), b = 7.033(1), c = 26.714(5) Å, and Z = 4 (R1(F) = 2.6% and wR2all(F2) = 7.3%, using 3066 ‘observed’ reflections with Fo > 4σ(Fo)). The crystal structure of Cs3ScSi8O19 represents a new microporous framework structure type (‘MCV-1’), and the compound is exceptional in being the first representative of a mixed octahedral-tetrahedral framework structure, in which the [TO4]:[MO6] ratio is >6:1. The structure is based on isolated, nearly regular ScO6 octahedra [dav(Sc—O) = 2.112 Å] sharing corners with SiO4 tetrahedra to form an open framework with four-, six- and eight-membered rings; the latter are formed by SiO4 tetrahedra only. Two fully occupied Cs positions are located in large framework voids close to the six-membered rings, whereas four partly occupied and disordered Cs positions are close to very large framework voids bordered by the puckered eight-membered rings. The cavities are linked into channels parallel to [100] and [010]. The structure is compared with that of Cs2TiSi6O15 and related microporous scandium-, REE-, titano- and zirconosilicate minerals and compounds. Cs3ScSi8O19 or derivatives may be important in the context of immobilization of radioactive 137Cs waste, cationic conductivity or catalysis.


1997 ◽  
Vol 12 (2) ◽  
pp. 81-86 ◽  
Author(s):  
J. M. S. Skakle ◽  
L. P. Moroni ◽  
F. P. Glasser

The X-ray powder diffraction patterns for two new synthetic calcium uranium (VI) silicate hydrate phases are reported. Ca1.5U6(OH)7O16·7H2O is orthorhombic, space group P*a*, with unit cell a=13.8949(14), b=12.0776(12), c=15.228(3) Å. The structure appears to be related to that of becquerelite. Ca2(UO2)2(Si2O5)3·10H2O was also indexed on an orthorhombic unit cell, a=12.075(3), b=15.406(6), c=26.043(6) Å. The Powder Diffraction File coverage of uranium-containing minerals which could, on the basis of their chemical formula, form in U-containing cements is also reviewed.


1998 ◽  
Vol 5 (5) ◽  
pp. 305-312 ◽  
Author(s):  
Maria Brezeanu ◽  
Mikaela Badea ◽  
Georges Morgant ◽  
Bernard Viossat ◽  
Sylvie Bouttier ◽  
...  

The synthesis of diaqua(1,10-phenanthroline-N,N′)(thiosulfato-O,S)manganese(ll) [Mn(phen)(S2O3)(H2O)2] was investigated. Its structure was determined by single crystal X-ray diffraction from 2418 reflections (I > 3 σ(I)) to a final value of R = 0.047 and Rw = 0.054. Crystal data are as follows : space group P21 ; a = 10.356(3), b = 7.097(3), c = 20.316(2) Å, β = 94.29(2)°, V = 1489.1(8) , Å3, Z = 2. There are two independent title compounds in the asymetric unit. Each manganese atom has a distorted octahedral Mn(SO)N2O2 geometry with the S and O atoms (from two neighbouring thiosulfate ligands) mutually trans, two N atoms from the 1,10-phenanthroline ligand and two water oxygen. The thiosulfate group behaves as a bridging ligand, connecting, through sulfur and oxygen, Mn atoms related by the binary b translation, thus forming infinite chains running parallel to this axis. Infrared and electronic spectra are reported.


1996 ◽  
Vol 61 (9) ◽  
pp. 1396-1404 ◽  
Author(s):  
Jan Čejka ◽  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Alexandr Jegorov ◽  
Ladislav Cvak

Two ergot alkaloid derivatives were examined by X-ray diffraction techniques. The crystal and molecular structure of ergometrine maleate (1) was evaluated from single-crystal data and the molecular structure of related methylergometrine maleate (2) was obtained by molecular modelling. The measured and calculated X-ray powder patterns of 1 and 2 were compared. Derivative 1 crystallizes in the orthorhombic space group P212121 with a = 5.7112(7) Å, b = 12.337(2) Å, c = 33.276(6) Å, Z = 4, V = 2 344.5(6) Å3. Derivative 2 is nearly isostructural with 1, it has slightly expanded unit cell, a = 5.724(2) Å, b = 12.762(6) Å, c = 33.25(2) Å, Z = 4, V = 2 428(1) Å3. No effect of an additional methyl group on the molecular packing of 2 was found.


1996 ◽  
Vol 51 (9) ◽  
pp. 1245-1247 ◽  
Author(s):  
Wolfgang Fachbereich Biologie-Chemie, Univer ◽  
Ulrich Fachbereich Biologie-Chemie, Univer

The title compound was obtained by the reaction of PPh4Br, Sb2Se3, and bromine in dichloromethane. Its crystal structure was determined by X-ray diffraction. Crystal data: a = 1249.1(2), b = 1307.8(2), c = 2152.3(4) pm, α = 102.93(2), β = 100.83(2), γ = 100.42(2)°, Z = 2, triclinic, space group P1̄. (PPh4)4Sb8Br28 is isotypic with (PPh4)4Sb8I28. The Sb8Br284- ion can be taken as the association product of eight SbBr3 molecules with four Br− ions. Each Sb atom has a distorted octahedral coordination with three shorter (252 to 274 pm) and three longer (300 to 353 pm) Sb-Br bonds. The octahedra share common edges in two parallel rows of four octahedra each. The arrangement of the 28 bromine atoms corresponds to a section of a closest packing of spheres.


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