Crystal and molecular structures and spectroscopic properties of dichloro(2,5-dimethyl-2',5'-diisocyanohexane)digold; evidence for quasi-one-dimensional linear chains with weak Au(I)...Au(I) interactions in the solid state

1991 ◽  
Vol 30 (1) ◽  
pp. 2-4 ◽  
Author(s):  
Daniel. Perreault ◽  
Marc. Drouin ◽  
Andre. Michel ◽  
Pierre D. Harvey
Keyword(s):  
Solid State ◽  
Spectroscopic Properties ◽  
Molecular Structures ◽  
One Dimensional ◽  
Crystal And Molecular Structures ◽  
Linear Chains

The Solid State Conformation of Diaryl Ditellurides and Diselenides: The Crystal and Molecular Structures of (C4H3E2)2E'2 (E = O, S; E' = Te, Se)

2000 ◽  
Vol 55 (5) ◽  
pp. 361-368 ◽  
Author(s):  
Raija Oilunkaniemi ◽  
Risto S. Laitinen ◽  
Markku Ahlgrén
Keyword(s):  
Solid State ◽  
Lone Pair ◽  
Spectroscopic Properties ◽  
Molecular Structures ◽  
Dihedral Angles ◽  
Single Bond ◽  
Aromatic Rings ◽  
Bond Lengths ◽  
Crystal And Molecular Structures ◽  
Solid State Conformation

The crystal and molecular structures of dithienyl ditelluride (C4H3S)2Te2 (1), difuryl ditelluride (C4H3O)2Te2 (2), dithienyl diselenide (C4H3S)2Se2 (3), and difuryl diselenide (C4H3O)2Se2 (4) are reported in this paper and compared to those of other simple diaryl ditellurides and diselenides. The chalcogen-chajcogen bonds exhibit approximately single bond lengths [Te-Te = 2.7337(8) and 2.7240(4) Å in 1 and 2, respectively; Se-Se = 2.357(1) and 2.368(2) Å in 3 and 4, respectively], as do the chalcogen-carbon bond lengths [Te-C = 2.095(9) - 2.104(6) in 1 and 2.091(6) - 2.105(9) Å in 2; Se-C = 1.87(1) - 1.90(1) Å in 3 and 1.887(8) - 1.897(10) Å in 4]. The aromatic rings are disordered. The dihedral angles C-E-E-C range from 79(2) to 96(1)° are consistent with the concept of minimized p lone-pair repulsion of adjacent chalcogen atoms. The dependence of molecular parameters on the angle between the aromatic rings and the chalcogen-chalcogen bonds follow trends established previously for aromatic disulfides. Though the bond parameters and conformations of 1 - 4 are similar, the packing of the molecules is different. The two ditellurides 1 and 2 show short Te···Te contacts (3.900 - 4.002 Å in 1 and 4.060 - 4.172 Å in 2). The two diselenides 3 and 4 do not exhibit close chalcogen-chalcogen interactions. The NMR spectroscopic properties of 1 - 4 are discussed.

Experimental and computational structural study of two hindered aminoanthraquinones in crystals and solutions

2000 ◽  
Vol 215 (9) ◽  
Author(s):  
A.V. Yatsenko ◽  
K.A. Paseshnichenko ◽  
S.I. Popov
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Electronic Spectra ◽  
Molecular Structures ◽  
Amino Group ◽  
Single Crystal Diffraction ◽  
Molecular Conformations ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Visible Spectra

The crystal and molecular structures of 2-methyl-1-methylamino-anthraquinone (I) and 1-methylphenylamino-anthraquinone (II) were studied by the X-ray single-crystal diffraction and the visible spectra of crystalline specimens and their solutions were recorded. The molecule I is closely planar, whereas in the molecule II the amino group is 58° rotated out of the plane of the anthraquinone skeleton. In both structures the molecules pack in stacks. The comparison of experimental and calculated (on the DFT and AM1 levels) molecular structures, together with the comparison of experimental and INDO/S-calculated electronic spectra, give the evidence that molecular conformations (especially for II) change upon transfer from the solid state to solutions, and the π-delocalisation throughout the whole molecule enhances in the solid state.

Crystal and molecular structures of 4-aryl-1,4-dihydropyrimidines: Novel calcium channel antagonists

2003 ◽  
Vol 218 (1) ◽  
Author(s):  
K. Chandra Mohan ◽  
K. Ravikumar ◽  
M. M. Shetty ◽  
D. Velmurugan
Keyword(s):  
Solid State ◽  
Calcium Channel ◽  
Molecular Structures ◽  
Calcium Channel Antagonists ◽  
Crystal And Molecular Structures ◽  
Solid State Structures

AbstractThe solid-state structures of three calcium channel antagonists viz. 1,4-dihydro-6-methyl-5-N-methyl-carbamoyl-4-(3′,4′-dichlorophenyl)-2(3 H)-pyrimidinethione, C

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