The crystal structure of (S)-( - )-6-Bromo-5,7-dihydroxy-8-methyl-2-phenyl-2,3-dihydro-4H-1-benzopyran-4-one [( - )-6-bromocryptostrobin] and a 13C N.M.R. study of (±)-cryptostrobin and related substances. Revision of the structures of the natural products (±)-lawinal, unonal, 7-O-methylunonal and isounonal

1982 ◽  
Vol 35 (9) ◽  
pp. 1851 ◽  
Author(s):  
LT Byrne ◽  
JR Cannon ◽  
DH Gawad ◽  
BS Joshi ◽  
BW Skelton ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Natural Products ◽  
Least Squares ◽  
Crystallographic Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Related Substances ◽  
Block Diagonal

The crystal structure of (S)-(-)-6-bromo-5,7-dihydroxy-8-methyl-2-phenyl-2,3-dihydro-4H-1-benzopyran-4-one [(–)-6-bromocryptostrobin] (11) has been determined by X-ray diffraction from diffractometer data at 295 K and refined by block diagonal least squares to a residual of 0.050 (810 'observed' reflections). Crystals of (11) are tetragonal, P43212, a 7.849(4), c 46.83(2) �, Z 8. The crystallographic data are consistent with the S configuration previously proposed for (–)-cryptostrobin (10). The 13C n.m.r, spectra of (�)-cryptostrobin and(�)-strobopinin also lead to the structures (1) and (6), respectively. This work has enabled the structures proposed for the natural products (�)-lawinal, unonal, 7-O-methylunonal and isounonal to be revised to (8), (14), (15) and (12), respectively.

Crystal structure and absolute configuration of (+)-scandine hydrobromide

1982 ◽  
Vol 35 (8) ◽  
pp. 1655 ◽  
Author(s):  
JR Cannon ◽  
KD Croft ◽  
Y Matsuki ◽  
VA Patrick ◽  
RF Toia ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Absolute Configuration ◽  
Steric Effect ◽  
X Ray Diffraction ◽  
Methyl Group ◽  
X Ray ◽  
Block Diagonal

The major alkaloid of a Fijian Melodinus sp. (family Apocynaceae) has been identified as (+)-scandine (1). The crystal structure and absolute configuration of the acetone solvate of (+)-scandine hydrobromide have been determined by X-ray diffraction; diffractometer data at 295 K were refined by block diagonal least squares to a residual of 0.037 (2657 'observed' reflections). Crystals of the hydrobromide are monoclinic, P21, a 9.496(3), b 14.561(5), c 9.339(3) �, β 115.39(2)�, Z 2. Although the cations of (+)-scandine hydrobromide and (+)-N-methylmeloscine bromide have the same skeleton and the same absolute configuration, they have different conformations; this appears to be due to the steric effect of the N-methyl group in the latter cation.

The molecular and crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2

1979 ◽  
Vol 57 (1) ◽  
pp. 57-61 ◽  
Author(s):  
R. Melanson ◽  
F. D. Rochon
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Platinum Atom ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
R Factor ◽  
Square Planar ◽  
Coordination Plane

The crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2 has been determined by X-ray diffraction. The crystals are orthorhombic, space group P212121, with a = 12.486(6), b = 13.444(7), c = 14.678(11) Å, and Z = 4. The structure was refined by block-diagonal least-squares analysis to a conventional R factor of 0.050 and a weighted Rw = 0.045.The coordination around the platinum atom is square planar. Guanosine is bonded to platinum through N(7). The purine planar ring makes an angle of 62.7° with the platinum coordination plane. The structure is stabilized by hydrogen bonding.

Crystal structure of ab-Bis(3-methylpyridine)-dc,fe-bis(pentane-2,3,4-trione 3-oximato)iron(II)

1978 ◽  
Vol 31 (11) ◽  
pp. 2431 ◽  
Author(s):  
BN Figgis ◽  
CL Raston ◽  
RP Sharma ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chelate Ligands

The crystal structure of the title compound has been determined at 295 K by single-crystal X-ray diffraction and refined by least squares to a residual of 0.062. Crystals are monoclinic, P2/c, a 19.102(8), b 8.117(4), c 16.610(8) Ǻ, β 111.90(3)°, Z. Unlike the tris(α-oxyimino ketonato)iron(II) complexes which are fac, the present derivative is based upon substitution of the two picoline moieties into a mer derivative, trans to the nitrogen atoms of the chelate ligands. <Fe- N(picoline)> is 2.020; <Fe-N, O(chelate)> 1.880, 1.952 Ǻ.

Crystal structure of (E)-7-t-Butyl-5-methoxy-3-[(E)-2'-methoxy-5',5'-dimethyl-4'-oxohex-2'-enylidene]benzofuran-2(3H)-one

1977 ◽  
Vol 30 (9) ◽  
pp. 1979 ◽  
Author(s):  
SR Hall ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Preceding Paper ◽  
X Ray Diffraction ◽  
X Ray

The crystal structure of (E)-7-t-butyl-5-methoxy-3-[(E)-2?-methoxy- 5?,5?-dimethyl-4?-oxohex-2?enylidene]benzofuran-2(3H)-one, C22H28O5 (see preceding paper), has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.067 (3735 ?observed? reflections). Crystals are triclinic, Pī, a 14.955(7), b 13.142(5), c 10.910(3) Ǻ, α 85.76(3), β 85.67(3), γ 80.12(3)�, Z 4.

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.

Crystal structure of Tetracyclo[5,3,1,12,6,04,9]dodecane (iceane)

1977 ◽  
Vol 30 (8) ◽  
pp. 1837 ◽  
Author(s):  
DPG Hamon ◽  
CL Raston ◽  
GF Taylor ◽  
JN Varghese ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Rigid Body ◽  
Least Squares ◽  
Title Compound ◽  
Molecular Geometry ◽  
Thermal Motion ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Hexagonal Close Packed

The crystal structure of the title compound, C12H18, has been determined at 295 K by X-ray diffraction and refined by full-matrix least squares to a residual of 0.049 for 216 ?observed? reflections; molecular geometry has been corrected for the effects of thermal motion using a rigid body approximation. Crystals are hexagonal, P63/m, a = 6.582(1), c = 11.843(3) Ǻ, Z = 2, the molecules occupying a hexagonal close- packed array.

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 Ethyltriphenylphosphonium Bis(α,α,α',α'-tetracyanoquinodimethanide)

1979 ◽  
Vol 32 (10) ◽  
pp. 2187 ◽  
Author(s):  
RJ Fleming ◽  
MA Shaikh ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Triphenyl Phosphonium

The crystal structure of the title compound, [EtPh3P]+ [(C12H4N4)2]-, has been established by single-crystal X-ray diffraction methods at 295(1) K and refined by least squares to a residual of 0�039 for 3047 'observed' reflections. Crystals are triclinic, Pī, a 8 �882(7), b 13�522(5), c 15�927(6) �, α 75�34(3), β 96�69(5), γ 100.56(3)�, Z 2. The structure closely resembles that of the methyl-triphenyl-phosphonium and -arsonium analogues, containing tetrads of α,α,α',α'- tetracyanoquino- dimethane* molecules, the molecular planes lying parallel to each other and approximately normal to b.

Crystal structure of cis-Tetracarbonylbis(chloromercury)iron

1976 ◽  
Vol 29 (9) ◽  
pp. 1905 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
SB Wild
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Diffraction Data ◽  
Title Compound ◽  
Direct Methods ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Independent Molecules

The crystal structure of the title compound has been determined by direct methods from X-ray diffraction data and refined by least squares to a residual of 0.071 for 2647 'observed' reflections. Crystals are monoclinic, C2/c, a = 36.81(1), b = 11.181(2), c = 20.369(5) �, β = 95.28(3)�, Z = 32. There are four independent molecules in the asymmetric unit, all with the cis disposition of ligands (<Fe-Hg), 2.498 �; <Hg-Fe-Hg), 80.9�); in one of the molecules one of the carbonyl sites is occupied by a more substantial moiety, possibly a result of partial occupancy of HgCl as a result of disorder or decomposition.

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.

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