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°.

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 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°.

Stress Modification in Tungsten Films Deposited by Ion-Assisted Evaporation

1988 ◽  
Vol 128 ◽  
Author(s):  
R. A. Roy ◽  
R. Petkie ◽  
D. S. Yee ◽  
J. Karasinski ◽  
A. Boulding
Keyword(s):  
Ion Bombardment ◽  
Film Stress ◽  
Clear Correlation ◽  
Original Structure ◽  
Qualitative Behavior ◽  
X Ray Diffraction ◽  
Ion Energy ◽  
X Ray ◽  
Impurity Model ◽  
The Relationship

ABSTRACTThe modification of film stress in evaporated tungsten was studied as a function of deposition environment. Using concurrent ion bombardment of the growing film, the stress was seen to vary systematically with ion energy, ion flux, and substrate temperature. The qualitative behavior fits the model of stress modification developed for niobium films. X-ray diffraction was used to study the structure of the films, and a clear correlation between crystallographic texture and film stress is found. The original structure/impurity model for film stress modification due to ion bombardment has been modified to account for the relationship between film stress and texture.

π-Electron delocalization in 2-benzoyl-5-phenylpyrazolidin-3-one

2018 ◽  
Vol 73 (8) ◽  
pp. 577-582
Author(s):  
Monika Olesiejuk ◽  
Agnieszka Kudelko ◽  
Katarzyna Gajda ◽  
Błażej Dziuk ◽  
Krzysztof Ejsmont
Keyword(s):  
Hydrogen Bonds ◽  
Density Functional ◽  
Heterocyclic Ring ◽  
Molecular Structures ◽  
Electron Delocalization ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Benzene Rings ◽  
Subsequent Cyclization

AbstractThe crystal and molecular structures of 2-benzoyl-5-phenylpyrazolidin-3-one have been characterized by X-ray diffraction along with density functional theory studies. Cinnamic acid chloride was reacted with benzhydrazide, yielding 2-benzoyl-5-phenylpyrazolidin-3-one. This product was formed in the transformation comprising the nucleophilic addition of benzhydrazide to the styryl fragment of the α,β-unsaturated arrangement and subsequent cyclization. The molecule contains two benzene rings and one five-membered heterocyclic ring with an N–N single bond. The five-membered ring is composed of three atoms of sp3 hybridization and two atoms of sp2 hybridization, which cause the flattening of the heterocyclic ring. The Harmonic Oscillator Model of Aromaticity and Nucleus-Independent Chemical Shift indexes, calculated for the benzene rings, demonstrate that there are no substantial interactions between the regions of π-electron delocalization in the molecule. In the crystal structure, there are N–H···O hydrogen bonds that link the molecules along the crystallographic c axis and weak intermolecular C–H···O hydrogen bonds.

Molecular Structures of Di(9-anthryl)Methanol and Di(9-anthryl) Ketone

1989 ◽  
Vol 42 (4) ◽  
pp. 603 ◽  
Author(s):  
HD Becker ◽  
V Langer ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Carbon Atom ◽  
Dihedral Angle ◽  
Molecular Structures ◽  
Steric Interaction ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Intramolecular Cycloaddition ◽  
X Ray ◽  
Central Carbon ◽  
Photochemical Isomerization

The molecular structures of di(9-anthryl)methanol (1) and di(9-anthryl) ketone (2) have been established by X-ray diffraction. The asymmetric unit of di(anthryl)methanol consists of two molecules in which the dihedral angle between the anthracene moieties is 81.4 and 86.3 respectively; steric interaction between the anthracene moieties results in them subtending angles of 115.0(7) and 115.8(8)� at the central carbon atom, and with unsymmetrical exocyclic angles at their point of attachment. In di(9-anthryl) ketone the planes of the anthracene systems are twisted out of the plane of the carbonyl group by 48.8 and 52.2� respectively, so that the dihedral angle between the two aromatic ring systems is 87.3�. The structures of di(anthryl)methanol and di(anthryl) ketone are discussed with respect to their different modes of photochemical isomerization by intramolecular cycloaddition.

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

scholarly journals Irregular Electrodeposition of Cu-Sn Alloy Coatings in [EMIM]Cl Outside the Glove Box with Large Layer Thickness

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 310
Author(s):  
Lars Lehmann ◽  
Dominik Höhlich ◽  
Thomas Mehner ◽  
Thomas Lampke
Keyword(s):  
Layer Thickness ◽  
Alloy System ◽  
Liquid Solution ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
X Ray ◽  
Argon Stream ◽  
Ionic Liquid Solution ◽  
The Relationship ◽  
Layer Composition

Thick Cu−Sn alloy layers were produced in an [EMIM]Cl ionic-liquid solution from CuCl2 and SnCl2 in different ratios. All work, including the electrodeposition, took place outside the glovebox with a continuous argon stream over the electrolyte at 95 °C. The layer composition and layer thickness can be adjusted by the variation of the metal-salts content in the electrolyte. A layer with a thickness of up to 15 µm and a copper content of up to ωCu = 0.86 was obtained. The phase composition was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF). Furthermore, it was found that the relationship between the alloy composition and the concentration of the ions in the electrolyte is described as an irregular alloy system as according to Brenner. Brenner described such systems only for aqueous electrolytes containing complexing agents such as cyanide. In this work, it was confirmed that irregular alloy depositions also occur in [EMIM]Cl.

Strukturuntersuchungen an Diaryldichalkogeniden: Die Molekülstrukturen von [2,4,6-(CF3)3C6H2S]2,[2,4,6-Me3C6H2Te]2 und [2-Me2N-4,6-(CF3)2C6H2Te]2 / Structural Investigations of Diaryl Dichalcogenides: The Molecular Structures of [2,4,6-(CF3)3C6H2S]2, [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2

1992 ◽  
Vol 47 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Anja Edelmann ◽  
Sally Brooker ◽  
Norbert Bertel ◽  
Mathias Noltemeyer ◽  
Herbert W. Roesky ◽  
...  
Keyword(s):  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Structural Investigations ◽  
Space Group ◽  
X Ray

Abstract The Molecular Structures of [2,4,6-(CF3)3C6H2S]2 (1) [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2 (3) have been determined by X-ray diffraction. Crystal data: 1: orthorhombic, space group P212121, Z = 4, a = 822.3(2), b = 1029.2(2), c = 2526.6(5) pm (2343 observed independent reflexions, R = 0.042); 2: orthorhombic, space group Iba 2, Z = 8, a = 1546.5(2), b = 1578.4(2), c = 1483.9(1) pm (2051 observed independent reflexions, R = 0.030); 3: monoclinic, space group P 21/c, Z = 4, a = 1118.7(1), b = 1536.5(2), c = 1492.6(2) pm, β = 98.97(1)° (3033 observed independent reflexions, R = 0.025).

Synthesis and characterization of meso-to-meso directly linked porphyrin-diazaporphyrin triads

2018 ◽  
Vol 22 (09n10) ◽  
pp. 814-820
Author(s):  
Yingying Jia ◽  
Ling Xu ◽  
Bangshao Yin ◽  
Mingbo Zhou ◽  
Jianxin Song
Keyword(s):  
Nickel Complex ◽  
High Resolution Mass Spectrometry ◽  
Dihedral Angles ◽  
X Ray Diffraction ◽  
Extinction Coefficients ◽  
X Ray ◽  
H Nmr ◽  
First Time ◽  
Molar Extinction Coefficients

Beginning with 5,10,15-triarylporphyrin-nickel complex, five meso-to-meso directly linked porphyrin-diazaporphyrin triads were successfully prepared for the first time through a series of reactions including formylation via Vilsmeier–Haack reaction, condensation with pyrrole, bromination with [Formula: see text]-Bromosuccinimide (NBS), oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), metal-templated cyclization of dibromodipyrrin-metal complexes with NaN[Formula: see text] and demetalization. All these triads were comprehensively characterized by [Formula: see text]H NMR, high-resolution mass spectrometry and UV-vis absorption. In addition, the structure of compound 6Ni was unambiguously determined by X-ray diffraction analysis, which showed that the two dihedral angles are both 86.65 (4)[Formula: see text] between each mean plane of porphyrin and that of central diazaporphyrin The UV-vis absorption spectra disclosed that the longest wavelengths of Soret bands and Q bands for these triads were observed at 429 and 642 nm, respectively. In contrast to diazaporphyrin-porphyrin dyads, diazaporphyrin dimers and diazaporphyrin monomers reported previously the molar extinction coefficients, particularly for triad 8Ni are much higher.

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