Crystal structure of triclinic rubidium dichromate, Rb2Cr2O7

1970 ◽  
Vol 48 (4) ◽  
pp. 537-543 ◽  
Author(s):  
N. Ch. Panagiotopoulos ◽  
I. D. Brown
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Dichromate Ions ◽  
Oxygen Atoms

The crystal structure of triclinic rubidium dichromate has been determined by single crystal X-ray diffraction. The crystal belongs to space group [Formula: see text] with a = 13.554, b = 7.640, c = 7.735 Å, α = 93.64°, β = 98.52°, γ = 88.80° and has four Rb2Cr2O7 units in the unit cell. The final weighted agreement index after refinement by least-squares analysis is 0.058. The configuration of the dichromate ions is similar to that found in most other dichromate structures (Cr—O (bridging) = 1.78 Å, Cr—O (terminal) = 1.62 Å). The two non-equivalent Cr—O—Cr angles are 123 and 137°. The rubidium ions are surrounded by either 8 or 9 oxygen atoms at distances ranging from 2.86 to 3.31 Å. The structure of triclinic Rb2Cr2O7 is similar, but not identical, to that of triclinic K2Cr2O7.

Crystal structure of Bis(O-ethylxanthato)bis(quinolin-8-olato)tin(IV)

1978 ◽  
Vol 31 (12) ◽  
pp. 2641 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
G Winter
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Coordination Sphere ◽  
Title Compound ◽  
Point Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Atoms

The crystal structure of the title compound, [Sn(S2COEt)2(C9H6NO)2], has been determined by single-crystal X-ray diffraction at 298 K and refined by least squares to a residual of 0.049 for 1771 ?observed? reflections. Crystals are monoclinic, P21/n, a 12.21(1), b 24.33(1), c 9.159(7) Ǻ, β 102.12(6)°, Z 4. The environment of the tin atom is six- coordinate: the two coordinating sulfur atoms of the monodentate xanthate ligands lie cis in the coordination sphere [Sn-S, 2.484(4), 2.510(4) Ǻ], and one in turn trans to the two oxine nitrogen atoms [Sn- N, 2.260(8), 2.237(10) Ǻ]. The remaining positions, trans to each other, are occupied by the oxine oxygen atoms [Sn-O, 2.047(7), 2.065(8) Ǻ]. O-Sn-O is 157.0(3)°. The overall point symmetry of the molecule is a good approximation to 2.

Crystal structure of zerumbone [(E,E,E)-2,6,9,9-Tetramethylcycloundeca-2,6,10-trien-1-one]

1981 ◽  
Vol 34 (10) ◽  
pp. 2243 ◽  
Author(s):  
SR Hall ◽  
S Nimgirawath ◽  
CL Raston ◽  
A Sittatrakul ◽  
S Thadaniti ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Membered Ring ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Zingiber Zerumbet ◽  
Space Group ◽  
X Ray ◽  
Considerable Distortion

The crystal structure of zerumbone, C15H22O, extracted from the rhizomes of Zingiber zerumbet Smith, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.051 for 925 'observed' reflections. Crystals are monoclinic, space group P21/c, a 9.036(3), b 9.712(5), c 15.643(6) �, β 97.19(3)�, Z = 4. Although the molecule has no chiral centre, the presence of the three trans double bonds confers considerable distortion and rigidity on the eleven-membered ring and renders the whole molecule chiral and potentially resolvable.

Molecular and crystal structure of a copper(II) complex of sildenafil

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akhmatkhodja N. Yunuskhodjayev ◽  
Shokhista F. Iskandarova ◽  
Vahobjon Kh. Sabirov
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Piperazine Ring ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Abstract The crystal structure of a copper(II) complex of protonated sildenafil, CuCl3C22H31N6O4S⋅2H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n with the unit cell parameters a = 15.4292(2), b = 9.06735(12), c = 21.1752(2) Å, V = 2945.48(7) Å3, Z = 4. The Cu atom is coordinated by the sildenafil ligand via the N2 atom of the pyrazolopyrimidine ring and by three chloride anions. Sildenafil is protonated at the methylated N6 atom of the piperazine ring and it is cation ligand with a 1+ charge.

scholarly journals Crystal structure of Tetraaqua(ethylenediamine)nickel(II) sulfate dihydrate and of Tetraaqua(2,2'-bipyridyl)nickel(II) sulfate dihydrate

1984 ◽  
Vol 37 (5) ◽  
pp. 921 ◽  
Author(s):  
PC Healy ◽  
JM Patrick ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Single Crystal ◽  
Least Squares ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Oxygen Atoms

The crystal structures of the title compounds, [Ni(OH2)4(en)] [SO4].2H2O, (1), and [Ni(OH2)4(bpy)]- [SO4].2H2O, (2), have been determined by single-crystal X-ray diffraction methods at 295 K, being refined by full matrix least-squares methods to residuals of 0.028,0.031 for 1852, 4323 independent 'observed' reflections respectively. Crystals of (1) are monoclinic, C2/c, a 9.459(4), b 12.192(7), c 12.294(3) �, β 119.84(4)�, Z 4. In the cation, Ni-N is 2.061(2) �; Ni-O (trans to O, N respectively) are 2.106(2), 2.063(2) �. Instead of being enlarged above 90� as predicted from repulsion theory, the angle between the pair of oxygen atoms trans to nitrogen is diminished, being 87 14(7)�. Crystals of (2) are triclinic, P1, a 11.476(5), b 9.351(5), c 7.793(4) �, α 77.63(4), β 83.52(3), γ87.40(4)�, Z 2. In the cation, Ni-N are both 2.063(2) �. Ni-O (trans to N, O respectively) are 2.060(2), 2.O42(2); 2.O80(2), 2�. The short Ni-O distance [2.042(2)�] is associated with the coordination of a trigonal water molecule.

Reactions between Co(II), 1,2-bis(diphenylphosphino)ethane, and NaBH3CN in the presence and absence of CO. The crystal structure of bis(cyanotrihydroborato)tetrakis(N,N-dimethylformamide)cobalt(II)

1988 ◽  
Vol 66 (7) ◽  
pp. 1770-1775 ◽  
Author(s):  
David J. Elliot ◽  
Sanna Haukilahti ◽  
David G. Holah ◽  
Alan N. Hughes ◽  
Stanislaw Maciaszek ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
R Factor

Reactions between Co(II), Diphos, and NaBH3CN lead to Co(BH3CN)2(Diphos)2, 1, or [Co(BH3CN)(Diphos)2]X, 2 (X = ClO4 or BPh4), and, in certain solvents, 2 reacts to produce [Co(CN)(Diphos)2](ClO4). Compound 1 can be reversibly converted to Co(BH3CN)2(DMF)4, 4, via Co(BH3CN)2(Diphos)(DMF). In addition, 1 reacts with CO to form the Co(I) and Co(III) compounds [Co(Diphos)2](CO)]X and [Co(Diphos)2(CN)2]X (X = BH3CN or BPh4). Single crystal X-ray diffraction studies of 4 show that the compound crystallizes in the triclinic space group [Formula: see text], with unit cell parameters a = 7.572(6), b = 9.695(6), c = 9.395(6) Å, α = 81.06(4), β = 68.46(5), γ = 68.19(5)°, V = 595.5 Å3, Z = 1, and dcalcd = 1.202 g cm−3. The structure converged to a conventional R factor of 0.040 for 2841 observations and showed an octahedral arrangement of four O atoms from DMF molecules and two trans N-bound BH3CN groups around the Co(II) center.

Crystal structure of Tris(N,N-diethyldithiocarbamato)thallium(III)

1978 ◽  
Vol 31 (9) ◽  
pp. 1927 ◽  
Author(s):  
DL Kepert ◽  
CL Raston ◽  
NK Roberts ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Electron Pair ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

The crystal structure of the title compound, [Tl(S2CNEt2)3], has been determined by single-crystal X-ray diffraction methods at 295 K and refined by full-matrix least squares to a residual of 0.050 for 2517 'observed' reflections. Crystals are monoclinic, with space group A2/a, a 14.789(7), b 10.428(4), c 18.207(9) Ǻ, β 118.11(4)°, Z 4, and are isostructural with those of the previously determined gallium and indium analogues, the molecule having 2 symmetry with <Tl-S> 2.666 Ǻ. As in the dimethyl/thallium analogue, the departure of the TlS6 core symmetry from 3 is large and is examined in terms of electron-pair repulsion theory.

Crystal Structure of Disodium(I) cis-Bis(ethane-1,2-diamine)disulfitocobaltate(III) Perchlorate Trihydrate

1979 ◽  
Vol 32 (2) ◽  
pp. 291 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
JK Yandell
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Sodium Ions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Atoms

The crystal structure of the title compound, Na2C104 [CO(C2N2H8)2(SO3)2],3H2O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.033 for 2693 'observed' reflections. Crystals are monoclinic, P21/c, a 16.271(3), b 12.298(2), c 9.567(2) �, β 105.85(1)�, Z 4. The Co-S distances differ significantly, probably a consequence of interaction of the sulfite oxygen atoms with adjacent sodium ions [Co-S, 2.206(1), 2.233(1) �]; the Co-N distances trans to the sulfite groups are significantly longer [2.015(3), 2.003(4) �] than those trans to each other [1.964(4), 1.959(3) �].

Crystal structure of 3,3a',5,5'-tetra-t-butyl-2'-(3,5-di-t-butyl-4-hydroxyphenyl)-7'-[l -(3,5-di-t-butyl-4-hydroxypheny1)ethy1idene]-3a',4',7',7a'-tetrahydrospiro-[cyclohexa-2,5-diene-1,1 '-[1H]indene]-4,4'-dione

1980 ◽  
Vol 33 (2) ◽  
pp. 295
Author(s):  
SR Hall ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Molecules

The crystal structure of the title compound, C60H86O4, has been determined at 295 K by single-crystal X-ray diffraction and refined by least squares to a residual of 0.073 for 3399 'observed' reflections. Crystals are monoclinic, P21/n, a 18.999(10), b 12.149(7), c 27.589(10) Ǻ, β 107.32(6)°, Z 4. The compound is solvated with ether to the extent of about two solvent molecules per unit cell.

Crystal Structure of Tetraethylammonium Bromopentacarbonyltungstate(0)

1995 ◽  
Vol 48 (5) ◽  
pp. 1045 ◽  
Author(s):  
T Whyte ◽  
GA Williams
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
R Value

The crystal structure of tetraethylammonium bromopentacarbonyltungstate (0), [NEt4] [W(CO)5Br], has been determined by single-crystal X-ray diffraction methods at 22�1°C. Crystals are tetragonal, space group P4/n, with a 9.206(2), c 10.484(2) Ǻ, and Z 2. Full-matrix least-squares refinement gave a final R value of 0.034 for 820 independent reflections. The [W(CO)5Br]- anion possesses exact C4v symmetry, with bond lengths W-Br 2.736(1), W-COtrans 1.93(1) and W-COcis 2.034(6) Ǻ.

Oxotetrafluoro-vanadate(V): Die Kristallstruktur von [enH2] [VOF4(H2O)]2.

1976 ◽  
Vol 31 (5) ◽  
pp. 541-543 ◽  
Author(s):  
Helmut Rieskamp ◽  
Rainer Mattes
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Trans Position ◽  
Space Group ◽  
X Ray ◽  
In Trans ◽  
Oxygen Atoms

The crystal structure of [enH2][VOF4(H2O)]2 has been determined from X-ray diffractometer data. Crystals are monoclinic, space group C2/c with Z = 4 in a unit cell of dimensions a = 16.576(13), b = 7.781(4), c = 10.338(8) Å, β = 120.0(1)°.The structure was refined by least-squares methods to R 0.053 for 1436 reflections. The structure contains monomeric [VOF4(H2O)]⁻-ions with the oxygen atoms in trans position. The bond distances are 1.577 Å (terminal oxygen) and 2.333 Å (H2O molecule), resp. The V–F distances vary between 1.769(2) and 1.858(2) Å for fluorine atoms involved in strong hydrogen bonds.

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