The Molecular Geometry of Diastereoisomeric Bis[α-(9-anthryl)ethyl] Ethers

1985 ◽  
Vol 38 (9) ◽  
pp. 1417 ◽  
Author(s):  
H Becker ◽  
VA Patrick ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Least Squares ◽  
Dihedral Angle ◽  
Molecular Geometry ◽  
Dihedral Angles ◽  
Methyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Meso Form ◽  
Aromatic Systems

The crystal structures of racemic bis [α-(9-anthryl)] ether and its meso form have been determined by single-crystal X-ray diffraction methods at 295 K, being refined by least squares to residuals of 0.053 and 0.041 for 1868 and 3568 independent 'observed' reflections respectively. Crystals of the racemate are orthorhombic, Pcab, a 23.07(1), b 19.85(2), c 10.241(8) Ǻ, Z 8. Crystals of the meso form are triclinic, Pī , a 19.032(12), b 14.207(11), c 9.451(8) Ǻ, α 79.46(6), β 89.68(6), γ 68.97(5)°, Z 4. In the racemate , the dihedral angle between the methyl groups along the ether bonds is 12°, and the short axes of the anthracene moieties lie at an angle of about 120°. In the meso compound, for the two molecules the dihedral angles between the methyl groups along the ether bonds are 90 and 93°, the angle between the two anthracene moieties is 90°, and the interplanar angles between the partly overlapping aromatic systems are 46 and 43°.

Crystal structure of methyl 8-Iodo-4,5,7-trimethoxy-2-naphthoate

1977 ◽  
Vol 30 (10) ◽  
pp. 2313 ◽  
Author(s):  
DW Cameron ◽  
GI Feutrill ◽  
vB Lammerts ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Crystal Packing ◽  
Molecular Geometry ◽  
X Ray Diffraction ◽  
X Ray

The crystal structure of the title compound, C15H15IO5, has been determined by single crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.04 (2210 ?observed? reflections). Crystals are monoclinic, P21/c, a 10.294(5), b 18.868(9), c 7.549(6) Ǻ, β 90.29(5)�, Z 4. The molecular geometry apart from the iodine environment is as expected; the crystal packing is such that the iodine lies close to a symmetry-related neighbour at I...I 4.148(2) Ǻ and may account for the observed facile elimination of iodine from the solid on heating to 120�C.

Molecular Topology of Di(9-Anthryl)Ethanedione (9,9'-Anthril) and Some Generically Related Cyclic 1,2-Diketones

1991 ◽  
Vol 44 (2) ◽  
pp. 181 ◽  
Author(s):  
HD Becker ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Dihedral Angle ◽  
Molecular Structures ◽  
Dihedral Angles ◽  
Molecular Topology ◽  
Single Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intramolecular Cycloadditions ◽  
Crystal Modifications

The molecular structures of di (9-anthryl) ethanedione (9,9′-anthril) and those of four 1,2-diketones derived from 9,9′-anthril by way of intramolecular cycloadditions were investigated by single-crystal X-ray diffraction studies. Two crystal modifications of 9,9′-anthril were available and found to differ in the dihedral angles (43.9 and 178.3°) about the 1,2-dicarbonyl moiety. The 1,2-dicarbonyl group of the cyclobutanedione moiety in the anthril 4π+4π cyclomer is associated with a dihedral angle of 2.6°. In the anthril isomer derived by 4π+2π cycloaddition, an exceptionally long single bond is indicative of molecular strain. The molecular structures of a keto enol and of a novel 1,2-diketo substituted triptycene, both obtained from the 4π+2π cyclomer by acid-catalysed rearrangement and dehydrogenation, respectively, were established. The topological and spectroscopic differences between the keto en01 and its 1,2-diketo precursor are discussed.

The crystal and molecular structure of dipyrrolidylthiuram disulfide

1983 ◽  
Vol 36 (7) ◽  
pp. 1371 ◽  
Author(s):  
GA Williams ◽  
JR Statham ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Dihedral Angle ◽  
Crystal And Molecular Structure ◽  
Structural Parameters ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray

The crystal structure of dipyrrolidylthiuram disulfide has been determined by single-crystal X-ray diffraction techniques at 295 K. Crystals are monoclinic, space group C2/c, unit cell a 13.835(3), b 10.422(2), c 9.427(3) �, β 97.08(2)� and Z 4. Automatic diffractometry has provided significant Bragg intensities for 1402 independent reflections, and the structure has been refined by least-squares methods to R 0.037. The structure consists of discrete C4H8NC(S)S2C(S)NC4H8 molecules. Half of each molecule is crystallographically unique with distances S-S 2.002(1), and C-S 1.804(2) and 1.645(2) �. The dihedral angle between planar C2NC(S)S portions is 87.9�. The relevance of the derived structural parameters to the question of why the tris(pyrrolidine-1-carbodithioato)iron(III) complex is, uniquely, high spin is discussed.

Molecular Geometry of 1,2-Bis(9-anthryl)acetylene

1985 ◽  
Vol 38 (10) ◽  
pp. 1567 ◽  
Author(s):  
H Becker ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Least Squares ◽  
Spatial Separation ◽  
Molecular Geometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acetylenic Bond

The structure of 1,2-bis(9-anthryl)acetylene has been determined by single-crystal X-ray diffraction, being refined by least squares to a residual of 0.050 for 566 independent 'observed' reflections. Crystals are monoclinic, P21/c, a 12.432(5), b 5.112(1), c 18.758(8) Ǻ, β 126.58(2)°, Z 2. The molecule is centrosymmetric , with the two anthracene moieties coplanar. The spatial separation between H1/H8 and their centrosymmetric equivalents is 2.1 Ǻ. The length of the acetylenic bond is 1.193(10) Ǻ.

scholarly journals Relation between photochromic properties and molecular structures in salicylideneaniline crystals

2012 ◽  
Vol 68 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Kohei Johmoto ◽  
Takashi Ishida ◽  
Akiko Sekine ◽  
Hidehiro Uekusa ◽  
Yuji Ohashi
Keyword(s):  
Dihedral Angle ◽  
Steric Hindrance ◽  
Molecular Structures ◽  
Dihedral Angles ◽  
Clear Correlation ◽  
X Ray Diffraction ◽  
Photochromic Properties ◽  
X Ray ◽  
Benzene Rings ◽  
The Relationship

The crystal structures of the salicylideneaniline derivatives N-salicylidene-4-tert-butyl-aniline (1), N-3,5-di-tert-butyl-salicylidene-3-methoxyaniline (2), N-3,5-di-tert-butyl-salicylidene-3-bromoaniline (3), N-3,5-di-tert-butyl-salicylidene-3-chloroaniline (4), N-3,5-di-tert-butyl-salicylidene-4-bromoaniline (5), N-3,5-di-tert-butyl-salicylidene-aniline (6), N-3,5-di-tert-butyl-salicylidene-4-carboxyaniline (7) and N-salicylidene-2-chloroaniline (8) were analyzed by X-ray diffraction analysis at ambient temperature to investigate the relationship between their photochromic properties and molecular structures. A clear correlation between photochromism and the dihedral angle of the two benzene rings in the salicylideneaniline derivatives was observed. Crystals with dihedral angles less than 20° were non-photochromic, whereas those with dihedral angles greater than 30° were photochromic. Crystals with dihedral angles between 20 and 30° could be either photochromic or non-photochromic. Inhibition of the pedal motion by intra- or intermolecular steric hindrance, however, can result in non-photochromic behaviour even if the dihedral angle is larger than 30°.

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.

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.

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