Acta crystallographica Section B, Structural science, crystal engineering and materials最新文献

{"title":"Analysis of diffuse scattering in electron diffraction data for the crystal structure determination of Pigment Orange 13, C₃₂H₂₄Cl₂N₈O₂.","authors":"Tatiana E Gorelik, Sàndor L Bekő, Jaroslav Teteruk, Winfried Heyse, Martin U Schmidt","doi":"10.1107/S2052520623000720","DOIUrl":"10.1107/S2052520623000720","url":null,"abstract":"<p><p>The crystallographic study of two polymorphs of the industrial pyrazolone Pigment Orange 13 (P.O.13) is reported. The crystal structure of the β phase was determined using single-crystal X-ray analysis of a tiny needle. The α phase was investigated using three-dimensional electron diffraction. The electron diffraction data contain sharp Bragg reflections and strong diffuse streaks, associated with severe stacking disorder. The structure was solved by careful analysis of the diffuse scattering, and similarities of the unit-cell parameters with the β phase. The structure solution is described in detail and this provides a didactic example of solving molecular crystal structures in the presence of diffuse scattering. Several structural models were constructed and optimized by lattice-energy minimization with dispersion-corrected DFT. A four-layer model was found, which matches the electron diffraction data, including the diffuse scattering, and agrees with X-ray powder data. Additionally, five further phases of P.O.13 are described.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10088482/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9289212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural and magnetic properties of Y₃(GaAlFe)₅O₁₂ liquid-phase epitaxy films with low ferromagnetic resonance losses.","authors":"Yuanjing Zhang,&nbsp;Qinghui Yang,&nbsp;Yingli Liu,&nbsp;Aimin Hu,&nbsp;Ding Zhang,&nbsp;Han Li,&nbsp;Jingyan Yu,&nbsp;Jiantao Huang,&nbsp;Yongcheng Lu,&nbsp;Lei Zhang,&nbsp;Qiang Xue,&nbsp;Yilei Li,&nbsp;Lichuan Jin,&nbsp;Qiye Wen,&nbsp;Huaiwu Zhang","doi":"10.1107/S2052520623000483","DOIUrl":"https://doi.org/10.1107/S2052520623000483","url":null,"abstract":"<p><p>Ultra-thin rare earth iron garnet (RIG) films with a narrow ferromagnetic resonance (FMR) line width and a low damping factor have attracted a great deal of attention for microwave and spintronic applications. In this work, 200 nm Y₃(GaAlFe)₅O₁₂ garnet (GaAl-YIG) films were prepared on gadolinium gallium garnet (GGG) substrates by liquid-phase epitaxy (LPE) with low saturation magnetization. The microstructural properties, chemical composition, and magnetostatic and dynamic magnetization characteristics of the films are discussed in detail. According to the structural analysis, these films exhibit a low surface roughness of less than 0.5 nm. The GaAl-YIG films show an obvious temperature dependence of lattice parameter and strain state, and the film's parameter is perfectly matched with that of the GGG substrate at 810°C. There is a clear variation in the Pb level, which brings about a gradual enhancement of the coercivity and a diminution of the squareness ratio of magnetic hysteresis loops as the growth temperature is reduced. Slight changes in surface roughness, strain condition and content of Pb induce the FMR line width and damping factor to vary on a small scale. The line width is less than 10.17 Oe at 12 GHz and the damping factor is of the order of 10^-4. All these properties demonstrate that these ultra-thin GaAl-YIG films are of benefit for the development of devices operated at lower frequencies and in lower fields.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9281958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Refinement of the crystal structure of fresnoite, Ba₂TiSi₂O₈, from Löhley (Eifel district, Germany); Gladstone-Dale compatibility, electronic polarizability and vibrational spectroscopy of minerals and inorganic compounds with pentacoordinated Ti^IV and a titanyl bond.","authors":"Nikita V Chukanov,&nbsp;Olga N Kazheva,&nbsp;Reinhard X Fischer,&nbsp;Sergey M Aksenov","doi":"10.1107/S2052520622012045","DOIUrl":"https://doi.org/10.1107/S2052520622012045","url":null,"abstract":"<p><p>Most known compounds with five-coordinated Ti⁴⁺ are natural and synthetic titanosilicates. The crystal structure of natural fresnoite, Ba₂TiSi₂O₈ [tetragonal, space group P4bm, a = 8.510 (1) Å, c = 5.197 (1) Å, V = 376.4 (1) ų, Z = 2], has been refined to R = 0.011 on the basis of 807 unique single-crystal reflections with I > 2σ(I). Titanium has fivefold coordination with one short (`titanyl') bond of 1.692 (5) Å. Bonds in the TiO<sub>5</sub> polyhedron are discussed in comparison to analogous coordination polyhedra in other minerals and compounds. A review of all known compounds with Ti<sup>4+</sup>O<sub>5</sub> polyhedra shows that most of them are titanosilicates in which titanium forms a short Ti-O bond (∼1.61 to ∼1.77 Å). Poor Gladstone-Dale compatibility between chemical composition, optical characteristics and density of these compounds is explained by the anomalous contribution of <sup>[5]</sup>Ti<sup>4+</sup> to the optical properties as shown by calculations based on the relationship between electronic polarizabilities and refractive indices. An improved Gladstone-Dale coefficient of 0.29 is suggested for TiO<sub>2</sub> with <sup>[5]</sup>Ti<sup>4+</sup>. A negative correlation between `titanyl' bond lengths and wavenumbers of the bands of Ti-O stretching vibrations (in the range of 890-830 cm^-1) in infrared and Raman spectra is observed.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9635798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the thermal behaviour of the solvated structures of nifedipine.","authors":"Eleanor C L Jones, Kate E Goldsmith, Martin R Ward, Luis M Bimbo, Iain D H Oswald","doi":"10.1107/S2052520623001282","DOIUrl":"10.1107/S2052520623001282","url":null,"abstract":"<p><p>Understanding the solvation and desolvation of pharmaceutical materials is an important part of materials discovery and development. In situ structural data are vital to understand the changes to crystal form that may occur in the system. In this study, the isolation and characterization of seven solvates of the L-type calcium channel antagonist, nifedipine, is described using variable-temperature powder X-ray diffraction so that the structural evolution as a function of temperature can be followed. The solvates reported herein can be split into those that are structurally similar to the previously reported dimethyl sulfoxide (DMSO) and dioxane solvates and those that have a novel packing arrangement. Of particular note is the solvate with tetrahydrofuran (THF) which has a hydrogen-bonding motif between the nifedipine molecules very similar to that of metastable β-nifedipine. In addition to variable-temperature X-ray diffraction, the stability of the solid forms was assessed using differential scanning calorimetry and thermogravimetric analysis and indicates that in all cases desolvation results in the thermodynamically stable α-polymorph of nifedipine even with the THF solvate. From the diffraction data the pathway of desolvation during heating of the DMF solvate showed conversion to another likely 1:1 polymorph before desolvation to α-nifedipine. The desolvation of this material indicated a two-stage process; first the initial loss of 90% of the solvent before the last 10% is lost on melting. The methanol solvate shows interesting negative thermal expansion on heating, which is rarely reported in organic materials, but this behaviour can be linked back to the winerack-type hydrogen-bonding pattern of the nifedipine molecules.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10088478/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9289213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polytypism of Ln(SeO₃)(HSeO₃)·2H₂O compounds: synthesis and crystal structure of the first monoclinic modification of Nd(SeO₃)(HSeO₃)·2H₂O, DFT calculations and order/disorder description.","authors":"Alisher F Murtazoev,&nbsp;Peter S Berdonosov,&nbsp;Sergey M Aksenov,&nbsp;Alexey N Kuznetsov,&nbsp;Valery A Dolgikh,&nbsp;Yulia V Nelyubina,&nbsp;Stefano Merlino","doi":"10.1107/S2052520622012227","DOIUrl":"https://doi.org/10.1107/S2052520622012227","url":null,"abstract":"<p><p>Compounds with the general formula Ln³⁺(SeO₃)(HSeO₃)·2H₂O, where Ln = Sm³⁺, Tb³⁺, Nd³⁺ and Lu³⁺, are characterized by orthorhombic symmetry with space group P2₁2₁2₁ and unit-cell parameters in the ranges a ∼ 6.473-6.999, b ∼ 6.845-7.101, c ∼ 16.242-16.426 Å. Light-purple irregularly shaped crystals of a new monoclinic polytype of neodymium selenite Nd(SeO₃)(HSeO₃)·2H₂O have been obtained during a mild-condition hydrothermal synthesis. The monoclinic unit-cell parameters are: a = 7.0815 (2), b = 6.6996 (2), c = 16.7734 (5) Å, β = 101.256 (1)°, V = 780.48 (6) ų; space group P2₁/c. The crystal structures of Nd(SeO₃)(HSeO₃)·2H₂O polymorphs show order-disorder (OD) character and can be described using the same OD groupoid family, more precisely a family of OD structures built up from two kinds of non-polar layers (category IV). The first monoclinic maximum degree order (MDO) structure (MDO1-polytype) with space group P2₁/c can be obtained when the inversion centre is active in the L_2n-type layers, while the second MDO structure (MDO2-polytype) is orthorhombic with space group P2₁2₁2₁ and can be obtained when the [2₁--] operation is active in the L_2n-type layers. The structural complexity parameters and DFT calculations of both polytypes show that the polytype structures are extremely close energy-wise and almost equally viable from the point of total energy of the structure.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9281961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient modulation of a barium metal-organic framework using amino acids.","authors":"Manije Safari,&nbsp;Sima Sedghiniya,&nbsp;Janet Soleimannejad,&nbsp;Jan Janczak","doi":"10.1107/S2052520623001105","DOIUrl":"https://doi.org/10.1107/S2052520623001105","url":null,"abstract":"<p><p>In recent years, significant advances have been made in the precise control of the physical properties of metal-organic frameworks (MOFs) via the linker-modulated method in which modulators compete with linkers and impose kinetic limitations through crystal growth. In this regard, the structure of a new barium-organic framework [Ba(H₂BTC)₂(H₂O)₄]_n, BaBTC (BTC = 1,3,5-benzene tricarboxylic acid) is introduced, which allows the competitive coordination strategy and growth orientation of an alkaline-earth metal-organic framework (AEMOF) to be probed without sacrificing phase purity, porosity and crystallinity. The modulator effect of an assortment of amino acids on the particle size and morphology of BaBTC is investigated. Additionally, another new MOF [Ba(BTC)₂(H₂O)₃]_n.nH₂O, BaBTC-2, is synthesized through a change in the ligand concentration. This work gives a successful example of a modulation method for AEMOF synthesis by amino acids that may contribute towards targeting future avenues of nanomaterial synthesis.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9281962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytic description of nanowires II: morphing of regular cross sections for zincblende- and diamond-structures to match arbitrary shapes. Corrigendum.","authors":"Dirk König,&nbsp;Sean C Smith","doi":"10.1107/S2052520623000434","DOIUrl":"https://doi.org/10.1107/S2052520623000434","url":null,"abstract":"<p><p>Corrections to the article by König and Smith [Acta Cryst. (2022), B78, 643-664] are given.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10088477/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9293884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping structural correlations in real space.","authors":"Ray Osborn","doi":"10.1107/S2052520623002688","DOIUrl":"https://doi.org/10.1107/S2052520623002688","url":null,"abstract":"<p><p>An analysis of neutron and x-ray diffuse scattering from yttria-stabilized zirconia by Schmidt et al. [Acta Cryst. (2023), B79, 137-147] uses three-dimensional pair-distribution functions (3D-ΔPDF) to determine local structural correlations without the need for sophisticated modeling.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9650563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetric rotations and dimerization driven by normal to modulated phase transition in 4-biphenylcarboxy coupled L-phenylalaninate.","authors":"Somnath Dey,&nbsp;Supriya Sasmal,&nbsp;Saikat Mondal,&nbsp;Santosh Kumar,&nbsp;Rituparno Chowdhury,&nbsp;Debashrita Sarkar,&nbsp;C Malla Reddy,&nbsp;Lars Peters,&nbsp;Georg Roth,&nbsp;Debasish Haldar","doi":"10.1107/S2052520623000215","DOIUrl":"https://doi.org/10.1107/S2052520623000215","url":null,"abstract":"<p><p>Amongst the derivatives of 4-biphenylcarboxylic acid and amino acid esters, the crystal structure of 4-biphenylcarboxy-(L)-phenylalaninate is unusual owing to its monoclinic symmetry within a pseudo-orthorhombic crystal system. The distortion is described by a disparate rotational property around the chiral centers (ϕ_chiral ≃ -129° and 58°) of the two molecules in the asymmetric unit. Each of these molecules comprises planar biphenyl moieties (ϕ_biphenyl = 0°). Using temperature-dependent single-crystal X-ray diffraction experiments we show that the compound undergoes a phase transition below T ∼ 124 K that is characterized by a commensurate modulation wavevector, q = δ(101), δ = ½. The (3+1)-dimensional modulated structure at T = 100 K suggests that the phase transition drives the biphenyl moieties towards noncoplanar conformations with significant variation of internal torsion angle (ϕ^max_biphenyl ≤ 20°). These intramolecular rotations lead to dimerization of the molecular stacks that are described predominantly by distortions in intermolecular tilts (θ_max ≤ 20°) and small variations in intermolecular distances (Δd_max ≃ 0.05 Å) between biphenyl molecules. Atypical of modulated structures and superstructures of biphenyl and other polyphenyls, the rotations of individual molecules are asymmetric (Δϕ_biphenyl ≈ 5°) while ϕ_biphenyl of one independent molecule is two to four times larger than the other. Crystal-chemical analysis and phase relations in superspace suggest multiple competing factors involving intramolecular steric factors, intermolecular H-C...C-H contacts and weak C-H...O hydrogen bonds that govern the distinctively unequal torsional properties of the molecules.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10088479/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9289210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incommensurate structures and radiation damage in Rb₂V₃O₈ and K₂V₃O₈ mixed-valence vanadate fresnoites.","authors":"Andrzej Grzechnik,&nbsp;Vaclav Petříček,&nbsp;Dmitry Chernyshov,&nbsp;Charles McMonagle,&nbsp;Tobias Geise,&nbsp;Hend Shahed,&nbsp;Karen Friese","doi":"10.1107/S2052520623000999","DOIUrl":"https://doi.org/10.1107/S2052520623000999","url":null,"abstract":"<p><p>The structures and phase transitions to incommensurate structures in Rb₂V₃O₈ and K₂V₃O₈ mixed-valence vanadate fresnoites are studied with synchrotron single-crystal diffraction at low temperatures and ambient pressure. Although mixed satellite reflections are absent, the modulated structure of K₂V₃O₈ below 115 K is better described in (3 + 2)- than in (3 + 1)-dimensional space. The geometries of the VO₄ and VO₅ building units are rigid and it is mainly slight rotations of these polyhedra and small variation of the intermediate K-O distances that are modulated. Prolonged exposure to the high-brilliance synchrotron beam suppresses the incommensurate phase. The previously postulated phase transition to the incommensurate phase in Rb₂V₃O₈ at 270 K was not observed. One of the reasons could be that the intense radiation also affects the modulation in this material. Strategies to collect and analyse single-crystal diffraction data measured with very intense synchrotron radiation using modern low-noise pixel area detectors are discussed.</p>","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10088480/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9293885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}