Isolation and Crystal Structure of Limonidilactone—a Labdane Diterpene From Vitex limonifolia

1995 ◽  
Vol 48 (1) ◽  
pp. 133 ◽  
Author(s):  
S Aphaijitt ◽  
K Nimgirawath ◽  
A Suksamrarn ◽  
U Tooptakong
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Structure Determination ◽  
Spectroscopic Methods ◽  
Full Matrix ◽  
X Ray ◽  
Labdane Diterpene ◽  
Least Squares Techniques

The structure of a new labdane diterpene, limonidilactone , from the leaves of Vitex limonifolia Wall. ( Verbenaceae ) has been established by spectroscopic methods and a single-crystal X-ray structure determination. Crystals are orthorhombic, P212121, a 19.373(10), b 10.871(7), c 8.207(3) Ǻ, Z 4. Diffractometer data were refined by full-matrix least-squares techniques to a residual of 0.043 for 1436 independent 'observed' reflections.

Crystal Structure of N,N,N′,N′-Tetrakis-(trimethylsilyl)ethane-1,2-diamine

1985 ◽  
Vol 38 (11) ◽  
pp. 1729 ◽  
Author(s):  
LM Engelhardt ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Structure Determination ◽  
Title Compound ◽  
Full Matrix ◽  
X Ray ◽  
Methylene Groups

The title compound, [{(Me3Si)2NCH2}2], has been structurally characterized by a single-crystal X-ray structure determination at 130 K, being refined by full-matrix least-squares to a residual of 0.057 for 1244 'observed' reflections. Crystals are monoclinic, C2/c, a 21.00(2), b 9.089(8), c 11.744(9) Ǻ, β 92.31(7)°, Z 4. Molecules lie on inversion centres, but with some disorder of the methylene groups. Si -N are 1.735 Ǻ, and N-CH2 1.53(1) for the major fragment (70%). The nitrogen in the major fragment is approximately trigonal planar; Si -N- Si 124.6(3)°, Si -N-C 117.5(4), 115.5(4)°.

Crystal structure of (Z)-Cembr-4-ene-15,19,20-triol

1977 ◽  
Vol 30 (12) ◽  
pp. 2723 ◽  
Author(s):  
EN Maslen ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Single Crystal ◽  
Least Squares ◽  
Structure Determination ◽  
Title Compound ◽  
X Ray Diffraction ◽  
Relative Configuration ◽  
Macrocyclic Ring ◽  
X Ray

The crystal structure of the title compound, CZOH3803 [compound (1) in ref.'], has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.045 for 954 'observed' reflections. Crystals are monoclinic, P2', a 9.281(2), b 17.798(6), c 6.417(1) A, B 93.81(3)", Z 2. The structure determination establishes the relative configuration of the chiral centres within the 14-membered macrocyclic ring and shows the double bond to have the unusual (Z) configuration.

Crystal structure of 2,3-Dichloro-5,8-dihydroxynaphtho-1,4-quinone

1978 ◽  
Vol 31 (3) ◽  
pp. 555 ◽  
Author(s):  
GI Feutrill ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Benzene Ring ◽  
Title Compound ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
X Ray ◽  
The One ◽  
Least Squares Techniques

The crystal structure of the title compound has been determined at 295 K by single-crystal X-ray diffraction methods and refined by least- squares techniques to a residual of 0.049 for 1046 'observed' reflections. Crystals are monoclinic, P21/c, a 11.584(6), b 5.449(7), c 15.273(8) Ǻ, β 92.44(4)°, Z4. The pair of quinol hydrogen atoms are both located on the one benzene ring as the title indicates.

Crystal structure of Tris(ethane-1,2-diamine)nickel(II) diperchlorate monohydrate

1978 ◽  
Vol 31 (2) ◽  
pp. 415 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
AC Willis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Diffraction Data ◽  
Structure Determination ◽  
Title Compound ◽  
Thermal Motion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Very High

The crystal structure of the title compound, [Ni(en)3] (ClO4)2,H2O, has been determined from single-crystal X-ray diffraction data at 295(1) K and refined by least squares to a residual of 0.093 for 1400 'observed' reflections. Crystals are orthorhombic, P bca, a 17.043(7), b 15.922(6), c 13.496(5) Ǻ, Z 8. The precision of the structure determination is adversely affected by very high perchlorate thermal motion. <Ni-N> is 2.13 Ǻ.

Crystal structure of 8-Hydroxy-1H-naphtho[2,1,8-mna]xanthen-1-one

1984 ◽  
Vol 37 (8) ◽  
pp. 1763
Author(s):  
IR Castleden ◽  
LM Engelhardt ◽  
SR Hall ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Charge Transfer ◽  
Single Crystal ◽  
Least Squares ◽  
Interplanar Spacing ◽  
Charge Transfer Complexes ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray

The crystal structure of 8-hydroxy-1H-naphtho[2,1,8-mna]xanthen-1-one, C19H10O3, obtained as an indefinite methanolsolvate, has been determined at 295K by single-crystal X-ray diffraction methods, being refined by full matrix least squares to a residual of 0.056 for 892 independent 'observed' reflections. Crystals are monoclinic, P21/c, a 5.128(4), b 10.024(9), c 27.45(2) �, β 107.73(6)�, Z 4. The packing of the molecules is typically that of charge-transfer complexes, with an interplanar spacing of c.3.5 �.

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.

Structural studies in the iron(III)/chloride/α,α'-diimine system. III. Crystal structures of Tris(2,2'-bipyridine)iron(II) μ-Oxo-bis[trichloroferrate(III)] and of 'Compound A', μ-Oxo-bis[cis-chlorobis(1 ,10-phenanthroline)iron(III)] chloride solvate

1983 ◽  
Vol 36 (10) ◽  
pp. 2057 ◽  
Author(s):  
PC Healy ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Single Crystal ◽  
Least Squares ◽  
Structure Determination ◽  
Ionic Species ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Compound A ◽  
X Ray

The crystal structure of [Fe(bpy)3] [CI3FeOFeCI3] (1) has been determined by single-crystal X-ray diffraction at 295 K, and refined by least squares to a residual of 0.058 for 2002 'observed' reflections. Crystals are monoclinic, P21/c, a 9.616(3), b 26.264(6), c 13.821(7) Ǻ, β 99.68(2)°, Z4. In the cation, Fe-N distances range from 1.956(9) to 1 .989(10) Ǻ; in the anion, Fe-Cl distances range from 2.196(5) to 2.225(5) Ǻ. Fe-O distances are 1.763(11) and 1.740(11) Ǻ, and the Fe-O-Fe angle is 148.9(7)°. Recrystallization of 'compound A' from methanolic aqueous solution yields crystals with stoichiometry [{cis-Fe(phen)2Cl}2O]Cl2.nH2O( n ≈ 4.5) as established by structure determination (hampered by serious disorder); R is 0.09 for 749 'observed' reflections. Crystals are orthorhombic, Pcn2, a 18.05(1), b 13.83(1), c 10.481(6) Ǻ, Z 2. The Fe-N distances trans to each other are 2.12(3) and 2.13(3) Ǻ; Fe-N distances trans to Cl and O are 2.20(2) and 2.28(2) Ǻ, respectively. Fe-CI is 2.34(1) and Fe-O 1.787(6) A; Fe-O-Fe is 161(1)°. For crystals from aqueous solution, an isomorphous but larger unit cell is obtained [2754(7), cf. 2616(3) Ǻ3]; it is believed that this is a consequence of variable occupancy of the disordered solvent layers which lie parallel to bc between the ionic species.

Studies of β-Diketone Complexes of Rhenium(V). The Molecular and Crystal Structure of trans-Dichlorobis(pentane-2,4-dionato)rhenium(IV)

1973 ◽  
Vol 51 (13) ◽  
pp. 2073-2076 ◽  
Author(s):  
I. D. Brown ◽  
C. J. L. Lock ◽  
Che'ng Wan
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Molecular And Crystal Structure ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Bond Lengths ◽  
Dimeric Structure

One of the compounds obtained by reacting acetylacetone with oxoethoxodichlorobis(triphenylphosphine)rhenium(V) has been shown by single crystal X-ray diffraction to be trans-dichlorobis(pentane-2,4-dionato)rhenium(IV). The crystals are triclinic, a = 8.032(4), b = 8.344(6), c = 7.429(6) Å, α = 118.1(2), β = 92.3(2), γ = 55.5(2)°, [Formula: see text], Z = 1. Intensities were measured with a microdensitometer from photographs recorded on an integrating precession camera. Of the 991 measured reflections all were observed and 984 were used in the refinement. The structure was refined by full matrix least squares to an R2 value of 0.0685. The compound was found to be a trans-monomer, in contrast to the dimeric structure claimed to exist in solution. The ligand atoms bonded to rhenium lie almost exactly at the apices of an octahedron and the bond lengths (Re—Cl, 2.326(8); Re—O1, 1.97(1); Re—O2, 2.01(1) Å) are in the range expected.

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 ζ2' Martensite in Au-49.5at%Cd Alloy

1991 ◽  
Vol 246 ◽  
Author(s):  
Yutaka Emura ◽  
Takuya Ohba ◽  
Kazuhiro Otsuka
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Least Squares ◽  
Least Squares Method ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Lattice Constants

AbstractCrystal structure of the ζ2' martensite in a Au-49.5at%Cd ally has been analyzed by the single crystal x-ray diffraction method. The crystal lattice was trigonal and the lattice constants were a:0.8095(3) and c=o.57940(6) nm. There were 18 atoms in a unit cell. The space group was P3, which was different from that previously determined by Vatanayon and Hehemann. The structure was refined by the full matrix least squares method to a final R factor of 7.8% and a weighted R factor of 4.1%.

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