{"title":"Synthesis and crystal structure of a tripeptide comprising a centrally placed non-coded aromatic γ-amino acid","authors":"Purak Das, Suven Das, Arpita Dutta","doi":"10.1515/zkri-2024-0095","DOIUrl":"https://doi.org/10.1515/zkri-2024-0095","url":null,"abstract":"A protected tripeptide Boc-<jats:sc>l</jats:sc>-Leu-5-AIA-Aib-OMe was synthesized where <jats:italic>5</jats:italic>-aminoisophthalic acid (5-AIA), a rigid non-coded aromatic γ-amino acid is incorporated as central residue. The single crystal X-ray diffraction study indicates that the peptide self-assembles into supramolecular sheet through intermolecular hydrogen bonding interaction N–H⋯O and <jats:italic>π</jats:italic> ··· <jats:italic>π</jats:italic> interaction.","PeriodicalId":23855,"journal":{"name":"Zeitschrift für Kristallographie - Crystalline Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"1-Nitronaphthalene, a non-OD, non-MDO polytype","authors":"Matthias Schöbinger, Berthold Stöger","doi":"10.1515/zkri-2024-0089","DOIUrl":"https://doi.org/10.1515/zkri-2024-0089","url":null,"abstract":"Crystals of 1-nitronaphthalene were grown by evaporation of a methanol solution. The structure [<jats:italic>P</jats:italic>2<jats:sub>1</jats:sub>/<jats:italic>c</jats:italic>, <jats:italic>a</jats:italic> = 13.2780(13) Å, <jats:italic>b</jats:italic> = 3.8131(3)° Å, <jats:italic>c</jats:italic> = 31.851(3) Å, <jats:italic>β</jats:italic> = 91.173(8), <jats:italic>V</jats:italic> = 1,612.3 Å<jats:sup>3</jats:sup>] was solved from a crystal twinned by twofold rotation about [100]. Twinning is explained by the polytype character: layers with (idealized) <jats:italic>p</jats:italic>2<jats:sub>1</jats:sub>11 symmetry can connect via either 1‾ or 2<jats:sub>1</jats:sub> operations, leading to geometrically distinct pairs of layers. In the twin individuals, the two kinds of contacts alternate, at the composition plane two subsequent contacts of the same type are realized.","PeriodicalId":23855,"journal":{"name":"Zeitschrift für Kristallographie - Crystalline Materials","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Federica Bravetti, Robert Hühn, Simone Bordignon, Sylvia Reibeling, Martin U. Schmidt
{"title":"Crystal structure and tautomeric state of Pigment Red 48:2 from X-ray powder diffraction and solid-state NMR","authors":"Federica Bravetti, Robert Hühn, Simone Bordignon, Sylvia Reibeling, Martin U. Schmidt","doi":"10.1515/zkri-2023-0042","DOIUrl":"https://doi.org/10.1515/zkri-2023-0042","url":null,"abstract":"Pigment Red 48:2 is an industrially important hydrazone pigment, used for the colouration of plastics and printing inks. The crystal structure of the commercial phase was solved and refined from X-ray powder diffraction data. The phase (P.R.48:2, α-phase) was found to be a monohydrate with a chemical composition of Ca[C<jats:sub>18</jats:sub>H<jats:sub>11</jats:sub>ClN<jats:sub>2</jats:sub>O<jats:sub>6</jats:sub>S]·H<jats:sub>2</jats:sub>O. Its tautomeric state was investigated by multinuclear solid-state NMR. The <jats:sup>15</jats:sup>N CPMAS unambiguously revealed the compound to adopt the hydrazone tautomeric form in the solid state. In an unrestrained Rietveld refinement, the crystal structure did not significantly change. The crystal structure was confirmed by dispersion-corrected DFT optimisation, which also included the calculation of solid-state NMR chemical shifts. Heating the monohydrate to about 200 °C results in an anhydrate (P.R.48:2, β-phase), which has not been described before. Its crystal structure was determined by X-ray powder diffraction, and confirmed by DFT-D, too. Solid-state NMR spectra confirmed that the crystal structure of P.R.48:2 remains mostly unchanged upon dehydration and that also the hydrazone tautomeric form is maintained. Both crystal structures are similar and present a double-layer structure. The non-polar layer contains the phenyl and naphthalene moieties, whereas the polar/ionic layer comprehends the calcium ions, carboxylate, sulfonate, carbonyl groups and water molecules. The calcium ions have a coordination number of 8 and 7 in the monohydrate and anhydrate phases, respectively. For the corresponding Mn salt (Pigment Red 48:4), at least two phases were found, but the quality of the powder patterns did not allow determining their crystal structures.","PeriodicalId":23855,"journal":{"name":"Zeitschrift für Kristallographie - Crystalline Materials","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Md. Izzuddin Jundullah Hanafi, M. Mangir Murshed, Lars Robben, Thorsten M. Gesing
{"title":"Mechanochemical synthesis of (Mg1−x Fe x )2SiO4 olivine phases relevant to Martian regolith: structural and spectroscopic characterizations","authors":"Md. Izzuddin Jundullah Hanafi, M. Mangir Murshed, Lars Robben, Thorsten M. Gesing","doi":"10.1515/zkri-2024-0078","DOIUrl":"https://doi.org/10.1515/zkri-2024-0078","url":null,"abstract":"To fabricate metals from the base materials for future Mars exploration, synthesis of representative olivine phases and their structural and spectroscopic characterizations are of crucial importance. Using mechanochemical technique that mimics the mechanical weathering, a complete solid solution of (Mg<jats:sub>1−<jats:italic>x</jats:italic> </jats:sub>Fe<jats:sub> <jats:italic>x</jats:italic> </jats:sub>)<jats:sub>2</jats:sub>SiO<jats:sub>4</jats:sub> has been synthesized to investigate the associated crystal chemical properties. X-ray powder diffraction data Rietveld analysis confirms that each polycrystalline sample crystallizes in space group <jats:italic>Pbnm</jats:italic>. The average crystallite size ranges between 80(1) nm and 223(4) nm. Each lattice parameter increases with increasing Fe-content due to the larger Fe<jats:sup>2+</jats:sup> radius than that of Mg<jats:sup>2+</jats:sup>, following Vegard’s rule. For a given nominal chemical composition, substitution of Mg with Fe at the <jats:italic>M</jats:italic>1-site (4<jats:italic>a</jats:italic>: 0,0,0) is preferred to the <jats:italic>M</jats:italic>2-site (4<jats:italic>c</jats:italic>: <jats:italic>x</jats:italic>,<jats:italic>y</jats:italic>,¼). As a consequence, the average Fe-content lies slightly below the equivalence line for <jats:italic>x</jats:italic> = 0.2–0.8, indicating that the Fe/Mg ratio in the amorphous scattering content is most likely greater than unity. Characteristic Raman spectral features of the olivines have been explained in terms of the chemical composition (<jats:italic>x</jats:italic>). Simple regression models are demonstrated based on both X-ray diffraction and Raman spectroscopic data for the calculation of Mg/Fe in olivines. Diffuse reflectance UV/Vis spectra RATD analysis shows each olivine phase possesses direct band-gap between 3.38(3) eV and 4.90(3) eV. This study could keep valuable information to relevant databases for future human missions on Mars, in particular, for precise estimation of the representative olivines from the remote X-ray diffraction and spectroscopic data.","PeriodicalId":23855,"journal":{"name":"Zeitschrift für Kristallographie - Crystalline Materials","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ivan Bernal, Roger A. Lalancette, Ahmad Hudaihed, Pavel Kucheryavy
{"title":"The crystal and molecular structure of (R)-sirtinol – C26H22N2O2 – a chemo-sensitive enhancer and ligand in metal complexes with important bio-inorganic applications","authors":"Ivan Bernal, Roger A. Lalancette, Ahmad Hudaihed, Pavel Kucheryavy","doi":"10.1515/zkri-2024-0073","DOIUrl":"https://doi.org/10.1515/zkri-2024-0073","url":null,"abstract":"Sirtinol is a known inhibitor of sirtuin proteins – a family of deacetylases involved in the physiology of aging. Its crystalline structure has never been determined except when bound to Fe(III) where it participates in the seven-fold coordination of the metal or to Cu(II) where it acts as a bidentate or tridentate ligand. Herein, we describe the structure of this important molecule, as follows: (a) the prevalent form of the keto-enol tautomerism in the solid state, and (b) in solution. Do they match? If not, how? The crystals of (<jats:italic>R</jats:italic>)-sirtinol are characterized by a large number of <jats:italic>π–π</jats:italic> bonded interactions linking molecules in infinite ribbons, which, in turn, are linked by additional <jats:italic>π–π</jats:italic> interactions of a variety of types, and by hydrogen bonds. In the latter case, we confirm by NMR that the X-ray determined position of an important H atom is on a N atom rather than on an O, which is how the molecule is usually depicted.","PeriodicalId":23855,"journal":{"name":"Zeitschrift für Kristallographie - Crystalline Materials","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141778380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christopher S. Reuter, M. M. Murshed, Michael Fischer, T. Gesing
{"title":"Synthesis, characterization and structure-property relations in mullite-type Pb2(Pb1−x\u0000 Sn\u0000 x\u0000 )O4 solid solution","authors":"Christopher S. Reuter, M. M. Murshed, Michael Fischer, T. Gesing","doi":"10.1515/zkri-2024-0088","DOIUrl":"https://doi.org/10.1515/zkri-2024-0088","url":null,"abstract":"\u0000 The crystal structures of both Pb2PbO4 (Pb3O4) and Pb2SnO4 at room temperature can be described using mullite-type setting in the space groups P42/mbc and Pbam, respectively. At what chemical extend the crystal structure prefers either of the space groups would be an excellent playground in the Pb2(Pb1−x\u0000 Sn\u0000 x\u0000 )O4 solid solution. Members of the solid solutions have been prepared by solid-state reactions carried out in sealed quartz tubes. Each sample has been found to be phase pure confirmed by X-ray powder diffraction data Rietveld refinement. Samples with higher tin content require higher synthesis temperatures, and controlled decomposition of Pb3O4 serves as the source for both Pb2+ and Pb4+ cations. Since the Pb4+ cation is larger than Sn4+, the MO6 polyhedral volume decreases with increasing Sn-content. As such, each metric parameter shows a linear trend following Vegard’s rule. The concomitant contraction of the MO6 octahedra and the high stereo-chemical activity of the 6s\u0000 2 lone electron pairs of lead in the Pb2+O4 distorted pyramid results in symmetry reduction. DFT suggests dynamical instability of the tetragonal Pb3O4 while Pb2SnO4 keeps orthorhombic symmetry at low temperatures, which agrees well with the experimental findings. The global blue shift of the vibrational mode frequencies is explained by the quasi-harmonic approach. The indirect band-gap linearly increases from 2.1(1) eV (x = 0) to a maximum value of 2.5(1) eV for x = 0.8 followed by a sharp drop towards Pb2SnO4. Thermogravimetric analysis demonstrates higher thermal stability with increasing Sn-content, which is explained in terms of higher bond strength of Sn–O than that of Pb–O in the MO6 octahedra.","PeriodicalId":23855,"journal":{"name":"Zeitschrift für Kristallographie - Crystalline Materials","volume":"22 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141648057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}