ChemInform Abstract: X-RAY DETERMINATION OF THE STEREOCHEMISTRY AND MOLECULAR STRUCTURE OF 2,6-DINITRATO-9-THIABICYCLO(3.3.1)NONANE 9,9-DIOXIDE

1982 ◽  
Vol 13 (41) ◽  
Author(s):  
P. H. MCCABE ◽  
G. A. SIM
Keyword(s):  
Molecular Structure ◽  
X Ray

Molecular Structure of cis- and trans-Tergurides

1998 ◽  
Vol 63 (3) ◽  
pp. 425-433 ◽  
Author(s):  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Petr Sedmera ◽  
Vladimír Havlíček ◽  
Hana Votavová ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Absolute Configuration ◽  
Catalytic Hydrogenation ◽  
Ergot Alkaloid ◽  
Cd Spectra ◽  
X Ray ◽  
Relative Stereochemistry ◽  
Cis And Trans

Four isomers of terguride, a semisynthetic ergot alkaloid derivative, have been prepared by catalytic hydrogenation of (5R,8S)- and (5S,8S)-lisuride [1,1-diethyl-3-(6-methyl-8-ergolenyl)urea]. Relative stereochemistry of the isomers is based on NMR and CD spectra. Absolute configuration of all the series has been confirmed by the X-ray crystal structure determination of (5R,8S,10S)-terguride 2-bromobenzoate [1,1-diethyl-3-(6-methyl-8-isoergolenyl)urea, cis-dihydrolisuride].

4,4′-Bithiazoles as Ligands: Crystal and Molecular Structure of bis(O,O′-Nitrato)(2,2′-diphenyl-4,4′-bithiazole)copper(II) (Two Polymorphs)

2003 ◽  
Vol 56 (9) ◽  
pp. 949 ◽  
Author(s):  
S. Ali Asghar Torabi ◽  
Fahimeh Jamali ◽  
George A. Koutsantonis ◽  
Ali Morsali ◽  
Brian W. Skelton ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Low Temperature ◽  
Molecular Complex ◽  
Structure Determination ◽  
Crystal And Molecular Structure ◽  
Plane Angle ◽  
Asymmetric Unit ◽  
X Ray ◽  
Crystallographic Symmetry

A low-temperature single-crystal X-ray structure determination of the 1 : 1 adduct of copper(II) nitrate with 2,2′-diphenyl-4,4′-bithiazole (L) shows it to be a molecular complex with L behaving as a symmetrical N,N′ chelate, and the nitrate groups as unsymmetrical O,O′ chelates: [LCu(O2NO)2]. Two polymorphs, both monoclinic P21/c, have been obtained from acetonitrile (‘α’) and methanol (‘β’), respectively, with one molecule, devoid of crystallographic symmetry, in the asymmetric unit of each structure. The copper environments are distorted planar four-coordinate, cis-N2CuO2 (Cu–N 2.011(1), 1.973(1), Cu–O 1.995(1), 1.962(1) Å), ‘in-plane’ angle sum Σ 369.5°, with longer trans, axial contacts (Cu–O 2.455(1), 2.458(2) Å) for the α-form; respective values are 1.995(5), 1.991(4), 1.997(4), 1.973(3) Å, 360.4°, 2.500(4), and 2.396(4) Å for the β-form.

Crystal and Molecular Structure of 4-Arylhexahydro-1H,3H-pyrido[1,2-c]pyrimidine-1,3-dione Derivatives

2002 ◽  
Vol 57 (11) ◽  
pp. 1315-1319 ◽  
Author(s):  
Irena Wolska ◽  
Franciszek Herold
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Structure Determination ◽  
Phenyl Ring ◽  
Crystal And Molecular Structure ◽  
X Ray ◽  
Saturated Ring ◽  
Centrosymmetric Dimers

The X-ray crystal structure determination of 4-(2-methylphenyl)hexahydro-1H,3H-pyrido[ 1,2-c]pyrimidine-1,3-dione (2) and 4-(3-methylphenyl)hexahydro-1H,3H-pyrido[1,2-c]- pyrimidine-1,3-dione (3) is reported. The crystal structures show the formation of centrosymmetric dimers via intermolecular N-H···O hydrogen bonds. The saturated ring adopts a slightly distorted halfchair conformation in both 2 and 3. In either compound the planar phenyl ring is twisted with respect to the pyrimidine-1,3-dione fragment.

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