Explanation for the stacking disorder in tris(bicyclo[2.1.1]hexeno)benzene using lattice-energy minimisations

2012 ◽  
Vol 227 (12) ◽  
pp. 805-818 ◽  
Author(s):  
Martin U. Schmidt ◽  
Jürgen Glinnemann
Keyword(s):  
Lattice Energy ◽  
Stacking Disorder

scholarly journals Explanation of the stacking disorder in the β-phase of Pigment Red 170

2014 ◽  
Vol 70 (2) ◽  
pp. 296-305 ◽  
Author(s):  
Jaroslav L. Teteruk ◽  
Jürgen Glinnemann ◽  
Tatiana E. Gorelik ◽  
Anthony Linden ◽  
Martin U. Schmidt
Keyword(s):  
Layer Structure ◽  
Lattice Energy ◽  
Large Set ◽  
Electron Diffraction Investigation ◽  
Industrial Sample ◽  
Local Structures ◽  
Β Phase ◽  
Diffraction Patterns ◽  
Stacking Disorder ◽  
Good Agreement

The β-phase of Pigment Red 170, C26H22N4O4, which is used industrially for the colouration of plastics, crystallizes in a layer structure with stacking disorder. The disorder is characterized by a lateral translational shift between the layers with a componenttyof either +0.421 or −0.421. Order–disorder (OD) theory is used to derive the possible stacking sequences. Extensive lattice-energy minimizations were carried out on a large set of structural models with different stacking sequences, containing up to 2688 atoms. These calculations were used to determine the actual local structures and to derive the stacking probabilities. It is shown that local structures and energies depend not only on the arrangement of neighbouring layers, but also next-neighbouring layers. Large models with 100 layers were constructed according to the derived stacking probabilities. The diffraction patterns simulated from those models are in good agreement with the experimental single-crystal and powder diffraction patterns. Electron diffraction investigation on a nanocrystalline industrial sample revealed the same disorder. Hence the lattice-energy minimizations are able to explain the disorder and the diffuse scattering.

scholarly journals On the stacking disorder of DL-norleucine

2017 ◽  
Vol 73 (6) ◽  
pp. 1075-1084 ◽  
Author(s):  
Christian Czech ◽  
Jürgen Glinnemann ◽  
Kristoffer E. Johansson ◽  
Michael Bolte ◽  
Martin U. Schmidt
Keyword(s):  
Density Functional ◽  
Layer Structure ◽  
Lattice Energy ◽  
Double Layers ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Β Phase ◽  
Diffraction Patterns ◽  
Model Structures ◽  
Stacking Disorder

DL-Norleucine (2-aminohexanoic acid, C6H13NO2) forms a double-layer structure in all known phases (α, β, γ). The crystal structure of the β-phase was redetermined at 173 K. Diffraction patterns of the α- and β-phases frequently show diffuse streaks parallel to c*, which indicates a stacking disorder of the layers. A symmetry analysis was carried out to derive possible stacking sequences. Lattice-energy minimizations by force fields and by dispersion-corrected density functional theory (DFT-D) were performed on a set of ordered model structures with Z = 4, 8 and 16 with different stacking sequences. The calculated energies depend not only on the arrangement of neighbouring double layers, but also of next-neighbouring double layers. Stacking probabilities were calculated from the DFT-D energies. According to the calculated stacking probabilities large models containing 100 double layers were constructed. Their simulated diffraction patterns show sharp reflections for h + k = 2n and diffuse streaks parallel to c* through all reflections with h + k = 2n + 1. Experimental single-crystal X-ray diffraction revealed that at 173 K norleucine exists in the β-phase with stacking disorder. After reheating to room temperature, the investigated crystal showed a diffraction pattern with strong diffuse scattering parallel to c* through all reflections with h + k = 2n + 1, which is in good agreement with the simulated disordered structure.

scholarly journals Stacking disorder in Pigment Red 170 explained by lattice-energy minimizations

2012 ◽  
Vol 68 (a1) ◽  
pp. s238-s238
Author(s):  
J. Teteruk ◽  
M. U. Schmidt ◽  
T. Gorelik ◽  
A. Linden
Keyword(s):  
Lattice Energy ◽  
Stacking Disorder

“Preparation of Single Crystalline Gold Films for ED Studies”

1972 ◽  
Vol 30 ◽  
pp. 634-635
Author(s):  
Joseph D. C. Peng
Keyword(s):  
Crystal Morphology ◽  
Diffraction Theory ◽  
Scattering Matrix ◽  
Vacuum Evaporation ◽  
Gold Films ◽  
Matrix Formulation ◽  
Silver Films ◽  
Single Crystalline ◽  
Grating Pattern ◽  
Stacking Disorder

The relative intensities of the ED spots in a cross-grating pattern can be calculated using N-beam electron diffraction theory. The scattering matrix formulation of N-beam ED theory has been previously applied to imperfect microcrystals of gold containing stacking disorder (coherent twinning) in the (111) crystal plane. In the present experiment an effort has been made to grow single-crystalline, defect-free (111) gold films of a uniform and accurately know thickness using vacuum evaporation techniques. These represent stringent conditions to be met experimentally; however, if a meaningful comparison is to be made between theory and experiment, these factors must be carefully controlled. It is well-known that crystal morphology, perfection, and orientation each have pronounced effects on relative intensities in single crystals.The double evaporation method first suggested by Pashley was employed with some modifications. Oriented silver films of a thickness of about 1500Å were first grown by vacuum evaporation on freshly cleaved mica, with the substrate temperature at 285° C during evaporation with the deposition rate at 500-800Å/sec.

On the reliability of volume-based thermodynamics for inorganic-organic salts and coordination compounds with uncharged ligands

2017 ◽  
Author(s):  
Robson de Farias
Keyword(s):  
Coordination Compound ◽  
Coordination Compounds ◽  
Formation Enthalpy ◽  
Lattice Energy ◽  
Chemical Hardness ◽  
Acid Anion ◽  
Organic Salts ◽  
Density Values ◽  
Lattice Energies

In the present work, the reliability of the volume-based thermodynamics (VBT) methods in the calculation of lattice energies is investigated by applying the “traditional” Kapustinskii equation [8], as well as Glasser-Jenkins [3] and Kaya [5] equations to calculate the lattice energies for Na, K and Rb pyruvates [9-11] as well as for the coordination compound [Bi(C<sub>7</sub>H<sub>5</sub>O<sub>3</sub>)<sub>3</sub>C<sub>12</sub>H<sub>8</sub>N<sub>2</sub>] [17] (in which C<sub>12</sub>H<sub>8</sub>N<sub>2</sub> = 1,10 phenathroline and C<sub>7</sub>H<sub>5</sub>O<sub>3</sub><sup>-</sup>= <i>o</i>-hyddroxybenzoic acid anion). As comparison, the lattice energies are also calculated using formation enthalpy values for sodium pyrivate and [Bi(C<sub>7</sub>H<sub>5</sub>O<sub>3</sub>)<sub>3</sub>C<sub>12</sub>H<sub>8</sub>N<sub>2</sub>]. For the pyruvates, is verified that none of the considered approach, Kapustinskii, Glasser, Kaya or density, provides values that agrees in an acceptable % difference, with the lattice energy values calculated from the formation enthalpy values. However, it must be pointed out that Kaya approach, with deals with a chemical hardness approach is the better one for such kind of inorganic-organic salts. Based on data obtained for [Bi(C<sub>7</sub>H<sub>5</sub>O<sub>3</sub>)<sub>3</sub>C<sub>12</sub>H<sub>8</sub>N<sub>2</sub>] is concluded that the only one VBT method that provides reliable lattice energies for compounds with bulky uncharged ligands is that one based on density values (derived by Glasser-Jenkins).

Electron microscopy investigations on the mineral lorándite (TlAsS2) from Allchar in Macedonia

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tobias Necke ◽  
Maximilian Trapp ◽  
Stefan Lauterbach ◽  
Georg Amthauer ◽  
Hans-Joachim Kleebe
Keyword(s):  
Electron Microscopy ◽  
Single Crystals ◽  
Secondary Phase ◽  
Lattice Energy ◽  
Local Deformation ◽  
Crystal Defects ◽  
Coffee Bean ◽  
Electron Dose ◽  
Chemical Difference ◽  
Natural Mineral

Abstract In this paper, we report on electron microscopy studies of single crystals of the natural mineral lorándite, TlAsS2. The main focus of this investigation was to address the question as to whether those lorándite crystals are chemically and structurally homogeneous, in order to be utilized as an effective neutrino detector within the lorándite experiment (LOREX) project. Apart from few secondary minerals, being present only at the surface of the lorándite samples, scanning electron microscopy (SEM) indicated homogeneous crystals. Similarly, transmission electron microscopy (TEM) imaging revealed a homogenous and undisturbed crystal structure, with the only exception of local coffee-bean contrasts; however, rarely observed. These specific contrast variations are known to be a typical strain indicator caused by a local deformation of the crystal lattice. Energy-dispersive X-ray spectroscopy (EDS) in conjunction with electron energy-loss spectroscopy (EELS) did not show any significant chemical difference when analysing regions on or off those coffee-bean features, indicating a chemically homogenous mineral. Since the presence of lattice disturbing secondary phase precipitates could be excluded by imaging and complementary chemical analysis, crystal defects such as dislocations and stacking faults or minor fluid inclusions are discussed as the probable origin of this local elastic strain. The experimental results confirm that the studied lorándite single crystals fulfil all structural and chemical requirements to be employed as the natural mineral that allows to determine solar neutrino fluxes. In addition, critical issues regarding the rather challenging sample preparation of lorándite are reported and a quantification of the maximum tolerable electron dose in the TEM is presented, since lorándite was found to be sensitive with respect to electron beam irradiation. Furthermore, the limits of EDS measurements due to peak overlapping are shown and discussed utilizing the case of Pb in lorándite. In this regard, a comparison with the Tl- and Pb-containing natural mineral hutchinsonite, TlPbAs5S9, is also included.

scholarly journals Sintering behaviour, lattice energy and microwave dielectric properties of melilite-type BaCo2Si2O7 ceramics

2020 ◽  
Vol 6 (12) ◽  
pp. 126322 ◽  
Author(s):  
Xiao-Qiang Song ◽  
Wen Lei ◽  
Meng-Qi Xie ◽  
Jie Li ◽  
Xiao-Chuan Wang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Lattice Energy ◽  
Microwave Dielectric ◽  
Sintering Behaviour

Crystal structure and lattice energetics of 10-methylacridinium halides

2000 ◽  
Vol 53 (8) ◽  
pp. 627 ◽  
Author(s):  
Piotr Storoniak ◽  
Karol Krzyminski ◽  
Pawel Dokurno ◽  
Antoni Konitz ◽  
Jerzy Blazejowski
Keyword(s):  
Crystal Lattice ◽  
Lattice Energy ◽  
Enthalpies Of Formation ◽  
Triclinic Space Group ◽  
X Ray ◽  
Molecular Arrangement ◽  
Van Der Waals Contacts ◽  
Chloride Monohydrate ◽  
Insight Into

The crystal structures of 10-methylacridinium chloride monohydrate, bromide monohydrate and iodide were determined by X-ray analysis. The compounds crystallize in the triclinic space group, P¯1, with 2 molecules in the unit cell. The molecular arrangement in the crystals revealed that hydrogen bonds (in hydrates) and van der Waals contacts play a significant part in intermolecular interactions. To discover their nature, contributions to the crystal lattice energy arising from electrostatic (the most important since the compounds form ionic crystals), dispersive and repulsive interactions were calculated. Enthalpies of formation of the salts, their stability and susceptibility to decomposition could be predicted from a combination of crystal lattice energies with values of other thermochemical characteristics obtained theoretically or taken from the literature. The role of water in the stabilization of the crystal lattice of the hydrates is also explained. The information gathered has given an insight into the features and behaviour of compounds which can be regarded as models of a large group of aromatic quaternary nitrogen salts.

scholarly journals Blind crystal structure prediction of a novel second polymorph of 1-hydroxy-7-azabenzotriazole

2006 ◽  
Vol 62 (4) ◽  
pp. 642-650 ◽  
Author(s):  
Harriott Nowell ◽  
Christopher S. Frampton ◽  
Julie Waite ◽  
Sarah L. Price
Keyword(s):  
Crystal Structure ◽  
Structure Prediction ◽  
Structure Refinement ◽  
Lattice Energy ◽  
Polymorphic Form ◽  
Crystal Structure Prediction ◽  
Blind Test ◽  
Coupling Reagent ◽  
Energy Penalty ◽  
Alcohol Solvents

The commercially available peptide coupling reagent 1-hydroxy-7-azabenzotriazole has been shown to crystallize in two polymorphic forms. The two polymorphs differ in their hydrogen-bonding motif, with form I having an R_2^2(10) dimer motif and form II having a C(5) chain motif. The previously unreported form II was used as an informal blind test of computational crystal structure prediction for flexible molecules. The crystal structure of form II has been successfully predicted blind from lattice-energy minimization calculations following a series of searches using a large number of rigid conformers. The structure for form II was the third lowest in energy with form I found as the global minimum, with the energy calculated as the sum of the ab initio intramolecular energy penalty for conformational distortion and the intermolecular lattice energy which is calculated from a distributed multipole representation of the charge density. The predicted structure was sufficiently close to the experimental structure that it could be used as a starting model for crystal structure refinement. A subsequent limited polymorph screen failed to yield a third polymorphic form, but demonstrated that alcohol solvents are implicated in the formation of the form I dimer structure.

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