The Constituents of Marine Sponges. VII. The Absolute Stereochemistry of Aplyroseol-1.

1997 ◽  
Vol 50 (4) ◽  
pp. 391 ◽  
Author(s):  
Trevor W. Hambley ◽  
Walter C. Taylor ◽  
Stephen Toth
Keyword(s):  
Crystal Structure ◽  
Marine Sponges ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
The Absolute ◽  
Absolute Stereochemistry

The absolute stereochemistry of aplyroseol-1 (1), a diterpenoid isolated from Aplysillarosea Barrois, has been established as (5S; 7R; 8S; 9R; 10S; 13R; 14R; 15R) by determining the crystal structure of the p-bromobenzoyl derivative (3) by X-ray diffraction methods. The structure was refined to a residual of 0·032 for 1451 independent observed reflections. The crystals are monoclinic, space group P 21, a 6·668(8), b 20·04(1), c 10·974(3) Å, β 98·04(7)°.

Darstellung von Mononitropentahydrohexaborat(2-) und Kristallstruktur von M2[B6H5(NO2)], M = K, Cs / Preparation of Mononitropentahydrohexaborate(2—) and Crystal Structure of M2[B6H5(NO2)], M = K, Cs

1993 ◽  
Vol 48 (12) ◽  
pp. 1727-1731 ◽  
Author(s):  
A. Franken ◽  
W. Preetz ◽  
M. Rath ◽  
K.-F. Hesse
Keyword(s):  
Crystal Structure ◽  
Ion Exchange ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Dichloromethane Solution ◽  
Space Group ◽  
X Ray ◽  
Diethylaminoethyl Cellulose

By electrochemical oxidation of [B6H6]2- in the presence of nitrite ions and the base DBU in dichloromethane solution mononitropentahydrohexaborate [B6H5(NO2)]2- ions are formed and can be isolated by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structures of the K and Cs salt were determined from single crystal X-ray diffraction analyses. K2[B6H5(NO2)] is monoclinic, space group P21/m with a = 5.953(1), b = 8.059(4), c = 8.906(1) Å, β = 109.553(9)°; Cs2[B6H5(NO2)] is monoclinic, space group P21/a with a = 9.438(6), b = 9.644(7), c = 11.138(9) Å, β = 101.44(9)°. The B6 octahedron is compressed in the direction of the B—NO2 bond by about 5%, with bond lengths between 1.67 and 1.77 A.

Crystal Structure and Vibrational Behaviour of Aqua Di(saccharinato)di(nicotinamide)copper(II)

2002 ◽  
Vol 57 (1) ◽  
pp. 43-46 ◽  
Author(s):  
Beatriz S. Parajón-Costaa ◽  
Enrique J. Baran ◽  
Oscar E. Piro ◽  
Eduardo E Castellano
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Ir Spectrum ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

The crystal structure of [Cu(sac)2(nic)2(H2O)] (sac = saccharinate anion; nic = nicotinamide) has been determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group C2/c with Z = 4 and the Cu(II) ion presents a CuN4O square pyramidal coordination. Some comparisons with related structures are made and the most important features of its IR spectrum were also discussed.

Anionische Komplexe [Mo2(O2CPh)4X2]2⊖ mit X = N3, Cl, Br. Die Kristallstruktur von (PPh4)2[Mo2(O2CPh)4Cl2] · 2CH2Cl2 / Anionic Complexes [Mo2(O2C-Ph)4X2]2⊖ with X = N3, Cl, Br. The Crystal Structure of (PPh4)2[Mo2(O2C-Ph)4Cl2] · 2CH2Cl2

1985 ◽  
Vol 40 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Kay Jansen ◽  
Kurt Dehnicke ◽  
Dieter Fenske
Keyword(s):  
Crystal Structure ◽  
Ir Spectra ◽  
Diffraction Data ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
Anionic Complexes

The syntheses and IR spectra of the complexes [Mo2(O2C-Ph)4X2]2⊖ with X = N3, CI, Br and the counter ion PPh4⊕ are reported. The azido and the bromo complexes are obtained from a solution of [Mo2(O2CPh)4] with PPh4N3 in pyridine or by reaction with PPh4Br in CH2Br2, respectively. When (PPh4)2[Mo2(O2CPh)4(N3)2] is dissolved in CH2Cl2, nitrogen is evolved and the complex with X = CI is obtained. The crystal structure of (PPh4)2[Mo2(O2CPh)4Cl2] · 2CH2Cl2 was determined from X-ray diffraction data (5676 observed independent reflexions, R = 0.042). It crystallizes in the monoclinic space group P21/n with four formula units per unit cell; the lattice constants are a = 1549, b = 1400, c = 1648 pm, β = 94.6°. The centrosymmetric [Mo2(O2CPh)4Cl2]2⊖ ion has a rather short Mo-Mo bond of 213 pm, whereas the MoCl bonds are very long (288 pm)

scholarly journals Serendipitous formation and characterization of K2[Pd(NO3)4]·2HNO3

2019 ◽  
Vol 74 (4) ◽  
pp. 381-387
Author(s):  
Michael Zoller ◽  
Jörn Bruns ◽  
Gunter Heymann ◽  
Klaus Wurst ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Monoclinic Space Group ◽  
Solvothermal Process ◽  
X Ray Diffraction ◽  
Glass Ampoule ◽  
Space Group ◽  
X Ray ◽  
Complex Anions

AbstractA potassium tetranitratopalladate(II) with the composition K2[Pd(NO3)4] · 2HNO3 was synthesized by a simple solvothermal process in a glass ampoule. The new compound crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 1017.15(4), b = 892.94(3), c = 880.55(3) Å, and β = 98.13(1)° (Z = 2). The crystal structure of K2[Pd(NO3)4] · 2HNO3 reveals isolated complex [Pd(NO3)4]2− anions, which are surrounded by eight potassium cations and four HNO3 molecules. The complex anions and the cations are associated in layers which are separated by HNO3 molecules. K2[Pd(NO3)4] · 2HNO3 can thus be regarded as a HNO3 intercalation variant of β-K2[Pd(NO3)4]. The characterization is based on single-crystal X-ray and powder X-ray diffraction.

The crystal structure of dibutyl-bis(pentamethylenedithiocarbamato)tin(IV)

1986 ◽  
Vol 51 (11) ◽  
pp. 2521-2527 ◽  
Author(s):  
Jan Lokaj ◽  
Eleonóra Kellö ◽  
Viktor Kettmann ◽  
Viktor Vrábel ◽  
Vladimír Rattay
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Coordination Polyhedron ◽  
Crystal And Molecular Structure ◽  
Distorted Octahedron ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

The crystal and molecular structure of SnBu2(pmdtc)2 has been solved by X-ray diffraction methods and refined by a block-diagonal least-squares procedure to R = 0.083 for 895 observed reflections. Monoclinic, space group C2, a = 19.893(6), b = 7.773(8), c = 12.947(8) . 10-10 m, β = 129.07(5)°, Z = 2, C20H38N2S4Sn. Measured and calculated densities are Dm = 1.38(2), Dc = 1.36 Mg m-3. Sn atom, placed on the twofold axes, is coordinated with four S atoms in the distances Sn-S 2.966(6) and 2.476(3) . 10-10 m. Coordination polyhedron is a strongly distorted octahedron. Ligand S2CN is planar.

The Constituents of Marine Sponges. IX New Norditerpenoids from Aplysilla pallida

1997 ◽  
Vol 50 (9) ◽  
pp. 903 ◽  
Author(s):  
Trevor W. Hambley ◽  
Walter C. Taylor ◽  
Stephen Toth
Keyword(s):  
Crystal Structures ◽  
Spectroscopic Studies ◽  
Marine Sponges ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

Four novel norditerpenoids were isolated from a new encrusting sponge, conveniently labelled Aplysilla pallida. The structures of aplypallidenone (1), aplypallidoxone (2), aplypallidione (3) and aplypallidioxone (4) were elucidated by spectroscopic studies and the crystal structures of aplypallidenone and aplypallidoxone have been determined by X-ray diffraction methods. The structure of (1) was refined to a residual of 0·040 for 1665 independent observed reflections and the structure of (2) was refined to a residual of 0·031 for 1699 independent observed reflections. The crystals of (1) are orthorhombic, space group P212121, a 7·728(2), b 10·838(4), c 24·880(5) Å, Z 4. Those of (2) are monoclinic, space group C 2, a 23·927(7), b 6·674(2), c 14·033(3) Å, Z 4.

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.

Die Kristallstruktur von Di-μ-hydroxo-bis[aquotriamminkobalt(III)]-nitrat-2-Hydrat / The Crystal Structure of Di-μ-hydroxo-bis[aquotriamminecobalt (III)] - nitrate-2-hydrate

1971 ◽  
Vol 26 (10) ◽  
pp. 987-989 ◽  
Author(s):  
Karl Wieghardt
Keyword(s):  
Crystal Structure ◽  
Complex Cation ◽  
Monoclinic Space Group ◽  
Spatial Behaviour ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Ray Methods

The crystal structure of Di-µ-hydroxy-bis [aquo-triamminecobalt (III)] nitrate-2-hydrate has been determined by x-ray diffraction using counter techniques. The compound crystallizes in the monoclinic space group C2h5-P21/n with a=9.444 (2), b=9.684 (3), c=10.736 (3) Å, β=90.1 (2)°, Z= 2. A total of 1765 independent reflections was used in solving the structure, which was refined to a conventional R1-factor of 0.047. It was not possible to distinguish by x-ray methods between the oxygen and nitrogen atoms of the NH3- and H2O molecules in the complex cation, because of their similarity in point of electrostatical and spatial behaviour.

Synthese und Kristallstruktur von [Hg2(p-SC6H4NO2)]NO3 / Synthesis and Crystal Structure of [Hg2(p-SC6H4NO2)]NO3

1990 ◽  
Vol 45 (8) ◽  
pp. 1193-1196 ◽  
Author(s):  
Klaus Brodersen ◽  
Axel Knörr
Keyword(s):  
Crystal Structure ◽  
Chain Structure ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
X Ray ◽  
Nitrate Ions ◽  
R Value ◽  
A Chain

[Hg2(p-SC6H4NO2)]NO3 is formed by the reaction of p-nitrothiophenol with dimercury(I)-dinitrate in methanol. It crystallizes in the monoclinic space group P21/n with a = 1175.5(9) pm, b = 1079.8(8) pm, c = 876.2(8) pm, β = 110.74(4)° and Z = 4. The crystal structure has been determined by X-ray diffraction and refined to an R-value of 0.052. The results show that the compound exists as a chain structure of [—®S(C6H4NO2)— Hg— Hg—]n with nitrate ions connecting the chains.

The Crystal Structure of (2,2′-Bipyridine)(pyrazine)(2,2′:6′,2″-terpyridine)ruthenium(II) Hexafluorophosphate

1996 ◽  
Vol 49 (4) ◽  
pp. 527 ◽  
Author(s):  
PT Gulyas ◽  
TW Hambley ◽  
PA Lay
Keyword(s):  
Crystal Structure ◽  
Monoclinic Space Group ◽  
Coordination Geometry ◽  
X Ray Diffraction ◽  
Steric Strain ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Distorted Octahedral ◽  
Back Bonding

The crystal structure of [ Ru ( terpy )( bpy )( pz )] (PF6)2 has been determined by X-ray diffraction methods and refined to a residual of 0.046 for 1855 independent observed reflections. The crystals are monoclinic, space group P 21/a, a 16.836(7), b 10.778(5), c l9.342(5) Ǻ, β 115.11(3)°. The coordination geometry around the ruthenium(II) ion is distorted octahedral, with the various Ru -N bond lengths indicative of considerable interligand steric strain. The Ru -N pyrazine bond is the longest within the structure, consistent with other evidence that n back-bonding to pyrazine is weak in the complex.

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