The X-Ray Crystal-Structure of (+/-)-Pandamarine, the Major Alkaloid of Pandanus-Amaryllifolius

1992 ◽  
Vol 45 (11) ◽  
pp. 1903 ◽  
Author(s):  
LT Byrne ◽  
BQ Guevara ◽  
WC Patalinghug ◽  
BV Recio ◽  
CR Ualat ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Least Squares Techniques ◽  
Pandanus Amaryllifolius

The structure (2) of ( �)-pandamarine , the major alkaloid isolated from the leaves of Pandanus amaryllifolius Roxb., has been determined by an X-ray diffraction study. Diffractometer data at 295 K were refined by least-squares techniques to a residual of 0.049 2244 'observed' reflections). Crystals of (2) are triclinic, P1, a 13.077(2), b 9.857(5), c 7.214(2) �, α 106.91(3), β 96.22(2), γ 100.01(2)0, Z 2.

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.

Röntgenstrukturbestimmung von AlCl3-Pyridin-Addukten: Der strukturelle Aufbau im trans-Dichlorotetrakis(pyridin)aluminium(III)- Tetrachloroaluminat(III) und im Trichlorotris(pyridin)aluminium(III) / X-ray Diffraction Study of AICl3-Pyridine Adducts: The Crystal Structure of trans-Dichlorotetrakis(pyridine)aluminium(III)tetrachloroaluminat(III) and of Trichlorotris(pyridine)aluminium(III)

1982 ◽  
Vol 37 (10) ◽  
pp. 1312-1315 ◽  
Author(s):  
Peter Pullmann ◽  
Karl Hensen ◽  
Jan W. Bats
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
The Mean

Abstract Crystals of [Al(C5H5N)4Cl2][AlCl4] are orthorhombic, Pna21, Z = 4, a = 18.522(7), b = 15.141(5), c = 9.593(3) Å, V = 2690(2) Å3 , Dc = 1.440 g/cm3 . The structure has been solved from 5968 diffractometer measured intensities and refined by full-matrix least squares to Rw(F) = 0.032. The crystal structure shows the complex to be trans-dichloro-tetrakis(pyridine)aluminium(III) tetrachloroaluminat(III). The mean trans Al-Cl-and trans Al-N-distances in the octahedron are 2.279(3) and 2.070(4) Å, respectively. Crystals of Al(C5H5N)3Cl3 are monoclinic, P21/c, Z = 4, a = 7.261(2), b = 29.961(4), c = 8.624(1) Å, β = 98.12(2)°, V -1857(1) Å3 , DC = 1.326 g/cm3 . The structure has been solved from 4707 diffractometer measured intensities and refined to Rw(F) = 0.028. The crystal structure shows octahedral complexes AlCl3·3 (C5H5N) with trans geometry. The Al-N-distance trans to chlorine (2.096(2) Å) is significantly longer than the two other Al-N-distances (mean 2.072(2) Å).

The Alkaloids of Margaritaria indica (Euphorbiaceae). The Crystal Structure and Absolute Configuration of the Hydrobromide of (+)-15α-Methoxy-14,15-dihydrophyllochrysine

1990 ◽  
Vol 43 (2) ◽  
pp. 439 ◽  
Author(s):  
D Arbain ◽  
LT Byrne ◽  
JR Cannon ◽  
LM Engelhardt ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Absolute Configuration ◽  
Spectroscopic Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Least Squares Techniques

(-)-Phyllochrysine (1), (-)-securinine (2) and a new alkaloid (+)-15α-methoxy-14,15-dihydrophyllochrysine (3) have been isolated from both the bark and roots of Margaritaria indica ( Dalz .) G. L. Webster. The structure and absolute configuration of (3) follow from its spectroscopic properties and its synthesis from (-)- phyllochrysine (1) as well as from the crystal structure of its hydrobromide, obtained by X-ray diffraction. Diffractometer data at 295 K were refined by least-squares techniques to a residual of 0.053 (991 'observed' reflections). Crystals of 15α-methoxy-14,15-dihydrophyllochrysine hydrobromide are orthorhombic, P212121, a 14.324(3), b 14.194(3), c 7.240(2)Ǻ, Z 4.

Crystal structure of Hexakis(urea)chromium(III) hexacyanochromate(III) Bis(dimethyl sulfoxide) bis(ethano/)

1984 ◽  
Vol 37 (2) ◽  
pp. 265 ◽  
Author(s):  
BN Figgis ◽  
ES Kucharski ◽  
JM Patrick ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Diffraction Study ◽  
Dimethyl Sulfoxide ◽  
Title Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Molecules

The crystal structure of the title compound, [Cr(OC(NH2)2)6] [Cr(CN)6].2(CH3)2SO.2CH3CH2OH, has been determined from a single-crystal X-ray diffraction study at 295(1) K. It was refined by least-squares methods to a residual of 0.039 for 4203 independent 'observed' reflections. Crystals are monoclinic, P21/n, a 17.449(6), b 10.315(4), c 11.726(3) �, β 102.51(2)�, Z 2. Both chromium atoms lie on crystallographic centres of symmetry. Cr-O(urea) are 1.960(2),1.962(2), 1.982(1) � and Cr-C(cyanide) 2.074(2), 2.080(2), 2.081(2) �; the geometries of the ligands and solvent molecules are correspondingly precise.

Selective O-Demethylation of 5,8-Dihydroxy-2,3-Dimethoxy-6-Methylnaphtho-1,4-Quinone: The Crystal Structures of 5,8-Dihydroxy-2,3-Dimethoxy-6-Methylnaphtho-1,4-Quinone and 2,5,8-Triacetoxy-3-Methoxy-6-Methylnaphtho-1,4-Quinone

1987 ◽  
Vol 40 (7) ◽  
pp. 1191 ◽  
Author(s):  
JR Cannon ◽  
Y Matsuki ◽  
VA Patrick ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Sodium Hydroxide ◽  
Crystal Structures ◽  
Hydrolysis Product ◽  
Aqueous Sodium Hydroxide ◽  
X Ray Diffraction ◽  
Aqueous Sodium ◽  
X Ray ◽  
Least Squares Techniques

It has been confirmed that treatment of 5,8-dihydroxy-2,3-dimethoxy-6-methylnaphtho-1,4- quinone (1) with dilute aqueous sodium hydroxide leads to selective O- demethylation. The hydrolysis product has been identified as 2,5,8-trihydroxy-3-methoxy-6-methylnaphtho1,4- quinone (3) from the crystal structure of the corresponding triacetate (4). The crystal structures of 5,8-dihydroxy-2,3-dimethoxy-6-methylnaphtho-1,4-quinone (1) and 2,5,8-triacetoxy-3-methoxy-6-methylnaphtho-1,4-quinone (4) were determined by X-ray diffraction; diffractometer data at 295 K were refined by least squares techniques to residuals of 0.074 (583 'observed' reflections) for (1) and 0.049 (2005) for (4). Crystals of (1) are monoclinic, P2l/c, a 3.873(4), b 20.21(1), c 15.OO(2) �, β 96.05(6)�, Z 4. Crystals of (4) are also monoclinic, P2l/c, a 10.532(5), b 14.596(6), c 12.097(6) �, β 109.74(4)�, Z 4.

Alkaloids of Templetonia retusa. Chemistry, Structure and Absolute Configuration of (-)-Templetine

1991 ◽  
Vol 44 (4) ◽  
pp. 509 ◽  
Author(s):  
JR Cannon ◽  
JR Williams ◽  
D Arbain ◽  
A Brossi ◽  
JF Blount ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Carbon Disulfide ◽  
Absolute Configuration ◽  
Perchloric Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Absolute ◽  
Absolute Structure ◽  
Least Squares Techniques

(-)-Cytisine, (+)-lupanine, (-)-anagyrine, (�)-piptanthine and (-)-templetine have been isolated from Templetonia retusa (Vent.) R.Br. The absolute crystal structures of the trihydrochloride dihydrate and the isomorphous trihydrobromide dihydrate of (-)- templetine have both been determined by single-crystal X-ray diffraction; diffractometer data at 295 K were refined by least-squares techniques to residuals of 0.045 and 0.031, respectively, for 2351 and 1948 'observed' reflections. Crystals of the trihydrochloride are orthorhombic P212121, a 8.830(4), b 14.201(6), c 19.122(12)Ǻ, Z 4. Crystals of the trihydrobromide are isomorphous, a 9.081(3), b 14.578(2), c 19.197(11)Ǻ, Z 4. The absolute structure (1) of (-)- templetine has led to the absolute structure of its dehydrogenation product (-)- dehydropiptanthine perchlorate (7) which, in turn, has allowed the absolute structures of (-)- ormosanine (6), (+)- piptanthine (4) and (-)- panamine (9) to be defined. (-)- Templetine (1) reacts with formaldehyde to form homotempletine (12) and with carbon disulfide to yield the thiourea (13). Treatment of either (12) or (13) with W-1 Raney nickel followed by perchloric acid has yielded the diperchlorate (15). The X-ray crystal structure of the diperchlorate (15) has also been determined: diffractometer data at 295 K were refined by least-squares techniques to a residual of 0.056 (1312 'observed' reflections). Crystals of the diperchlorate (15) are orthorhombic, P212121, a 18.636(5), b 12.569(6), c 10.403(4)Ǻ, Z 4.

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.

Powder X-ray diffraction study of disilver(1+) pentacyanonitrosylferrate(2−)

1999 ◽  
Vol 14 (3) ◽  
pp. 219-221 ◽  
Author(s):  
V. Venegas ◽  
A. Gómez ◽  
E. Reguera
Keyword(s):  
Crystal Structure ◽  
Thermogravimetric Analysis ◽  
Diffraction Study ◽  
Powder Diffraction ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray

The crystal structure of disilver(1+) pentacyanonitrosylferrate(2−) was studied by X-ray powder diffraction. IR and Mössbauer spectroscopies, thermogravimetric analysis and density measurements were also carried out. This compound is monoclinic, and its lattice parameters are: a=10.986(3) Å, b=6.4080(10) Å, c=7.4545(19) Å, α=δ=90°, β=102.54°(2).

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