ChemInform Abstract: SULFUR COMPOUNDS. 54. X-RAY STRUCTURAL ANALYSIS OF CYCLO-DECASULFUR, S10

1978 ◽  
Vol 9 (13) ◽  
Author(s):  
R. REINHARDT ◽  
R. STEUDEL ◽  
F. SCHUSTER
1992 ◽  
Vol 45 (11) ◽  
pp. 1923 ◽  
Author(s):  
KA Hellmund ◽  
SG Pyne ◽  
BW Skelton ◽  
AH White

The X-ray structural analysis of the title compound shows that the s-cis conformation is favoured in the solid state. This conformation is consistent with circular dichroism studies in methanol solution.


1993 ◽  
Vol 46 (1) ◽  
pp. 143 ◽  
Author(s):  
ZM Dong ◽  
SG Pyne ◽  
BW Skelton ◽  
AH White

The X-ray structural analysis of (E)-S-phenyl-S-(2-phenylethenyl)-N-(p- tolylsulfonyl ) sulfoximine and (E)-N-methyl-S-phenyl-S-(2-phenylethenyl) sulfoximine shows that the s- cis conformation, in which the C=C and S=O bonds are approximately syn coplanar, is favoured in the solid state.


Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.


1981 ◽  
Vol 46 (1) ◽  
pp. 6-19 ◽  
Author(s):  
Viktor Kettman ◽  
Ján Garaj ◽  
Jaroslav Majer

The crystal and molecular structure of [Cr(S2CN(CH2)5)3].2 CHCl3 was found by the X-ray structural analysis method. The value R 0.090 was found for 1 131 observed independent reflections. The substance crystallizes in a space group of symmetry P212121 with the following unit cell dimensions: a = 0.8675 (6), b = 1.815(2), c = 2.155(3) nm. The experimentally observed crustal density was 1.48 Mgm-3 and the value calculated for Z = 4 was 1.51 Mgm-3. The CrS6 coordination polyhedron has the shape of a trigonally distorted octahedron, where the D3 symmetry is a approximately retained. The degree of trigonal distortion expressed as the projection of the chelate S-Cr-S angle onto the plane perpendicular to the C3 pseudo axis is Φ = 41.7° (Φ = 60° for an octahedron). The skeleton of the structure formed by the complex molecules contains channels filled with chloroform molecules. The specific type of complex-chloroform interaction consists of the formation of hydrogen bonds of the chloroform protons with the fully occupied pπ-orbitals of the sulphur atoms in the coordination polyhedra. The low stability and crystal decomposition can be explained by loss of chloroform from the channels.


1999 ◽  
Vol 64 (6) ◽  
pp. 977-985 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz ◽  
Wolfgang Milius ◽  
Catherine McCammon

Sodium hexaethyl-2,4-dicarba-nido-hexaborate(1-) (6), available from hexaethyl-2,4-dicarba- nido-hexaborane(8) (4) by deprotonation, reacts with deuterated methanol, CD3OD, to give back 4 without H/D exchange of the B-H-B hydrogen atom. The reaction of 6 with diethylboron chloride, Et2BCl, affords hexaethyl-2,4-dicarba-closo-hexaborane(6) (7), the first example of a peralkylated carborane of this type. In contrast, the reaction of 6 with boron tribromide, BBr3, leads mainly to 2,3,4,5,6,7-hexaethyl-2,4-dicarba-closo-heptaborane(7) (8), together with the corresponding 1-bromo derivative (9) and the closo-carborane 7 as side products. The reaction of two equivalents of 6 with FeCl2 gives the air-stable sandwich complex bis[hexaethyl-2,4-dicarba-nido-hexaborate(1-)]iron 10 which was characterised by X-ray structural analysis. All products were characterised by 1H, 11B and 13C NMR spectroscopy, and 57Fe Mössbauer spectroscopy was used to study 10.


1987 ◽  
Vol 1987-7 (1) ◽  
pp. 165-174
Author(s):  
Yoshihiro OKAMOTO
Keyword(s):  

1999 ◽  
Vol 23 (1) ◽  
pp. xiv-xiv
Author(s):  
Nader A. Al-Jalal ◽  
Robin G. Pritchard ◽  
Charles A. McAuliffe
Keyword(s):  

6-Methoxy-2-naphthonitrile undergoes photocycloaddition to 2-chloroacrylonitrile to give [2 + 2] cyclobutane adducts (1a and 1b), the structure of one of which (1a) has been unambiguously confirmed by an X-ray structural analysis.


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