Karen-Christina Schipmann, Jörg Daniels, Johannes Beck
The electron-rich molecule tetramethoxythianthrene TMO-TA can readily be oxidized to the radical cation using various transition metal halides in acetonitrile as solvent. Reactions with CuBr2, FeCl3, AuCl3, NbCl5, and CuCl2 yield dark blue or black crystals of [TMO-TA]2[CuBr4] (2), [TMO-TA][FeCl4] · CH3CN (3), [TMO-TA][AuCl4] (4), [TMO-TA][NbCl6] · CH3CN (6), and [TMO-TA]5[Cu2Cl6]2 · 2 CH3CN (7). [TMO-TA]2[Ta2OF10] (5) was obtained by anodic oxidation of TMO-TA in the presence of (Nbu4)2[Ta2OF10] as electrolyte. Using mercury(II) bromide, no redox reaction occurs. Instead, the colorless complex [HgBr2(TMO-TA)] (1) is formed. In the crystal structures of the compounds 2–7, the almost planar radical cations show different types of arrangements. Pair formation of the [TMO-TA]•+ radicals to [TMO-TA]22+ dimers with the typical intra-pair S⋯S bonds of 3.1–3.2 Å lengths is predominant. Compounds 6 and 7 contain stacks of planar TMO-TA molecules in equidistant arrangement without pair formation and the unique feature of rotation of each adjacent cation by about 30°. Compounds 2, 5, and 7 are electrical semiconductors with band gaps between 0.62 and 1.4 eV, reflecting the arrangement of the radical cations. While 5 is diamagnetic, the magnetic momenta of 2 and 7 correspond only to the expected paramagnetic momenta of magnetically dilute Cu2+ ions. Electrons on the organic radicals are strongly paired in all compounds.
{"title":"Radical cations of chalcogenanthrenes with halogenido metalate anions. Part I: tetramethoxythianthrene","authors":"Karen-Christina Schipmann, Jörg Daniels, Johannes Beck","doi":"10.1515/znb-2024-0016","DOIUrl":"https://doi.org/10.1515/znb-2024-0016","url":null,"abstract":"The electron-rich molecule tetramethoxythianthrene TMO-TA can readily be oxidized to the radical cation using various transition metal halides in acetonitrile as solvent. Reactions with CuBr<jats:sub>2</jats:sub>, FeCl<jats:sub>3</jats:sub>, AuCl<jats:sub>3</jats:sub>, NbCl<jats:sub>5</jats:sub>, and CuCl<jats:sub>2</jats:sub> yield dark blue or black crystals of [TMO-TA]<jats:sub>2</jats:sub>[CuBr<jats:sub>4</jats:sub>] (2), [TMO-TA][FeCl<jats:sub>4</jats:sub>] · CH<jats:sub>3</jats:sub>CN (3), [TMO-TA][AuCl<jats:sub>4</jats:sub>] (4), [TMO-TA][NbCl<jats:sub>6</jats:sub>] · CH<jats:sub>3</jats:sub>CN (6), and [TMO-TA]<jats:sub>5</jats:sub>[Cu<jats:sub>2</jats:sub>Cl<jats:sub>6</jats:sub>]<jats:sub>2</jats:sub> · 2 CH<jats:sub>3</jats:sub>CN (7). [TMO-TA]<jats:sub>2</jats:sub>[Ta<jats:sub>2</jats:sub>OF<jats:sub>10</jats:sub>] (5) was obtained by anodic oxidation of TMO-TA in the presence of (Nbu<jats:sub>4</jats:sub>)<jats:sub>2</jats:sub>[Ta<jats:sub>2</jats:sub>OF<jats:sub>10</jats:sub>] as electrolyte. Using mercury(II) bromide, no redox reaction occurs. Instead, the colorless complex [HgBr<jats:sub>2</jats:sub>(TMO-TA)] (1) is formed. In the crystal structures of the compounds 2–7, the almost planar radical cations show different types of arrangements. Pair formation of the [TMO-TA]<jats:sup>•+</jats:sup> radicals to [TMO-TA]<jats:sub>2</jats:sub> <jats:sup>2+</jats:sup> dimers with the typical intra-pair S⋯S bonds of 3.1–3.2 Å lengths is predominant. Compounds 6 and 7 contain stacks of planar TMO-TA molecules in equidistant arrangement without pair formation and the unique feature of rotation of each adjacent cation by about 30°. Compounds 2, 5, and 7 are electrical semiconductors with band gaps between 0.62 and 1.4 eV, reflecting the arrangement of the radical cations. While 5 is diamagnetic, the magnetic momenta of 2 and 7 correspond only to the expected paramagnetic momenta of magnetically dilute Cu<jats:sup>2+</jats:sup> ions. Electrons on the organic radicals are strongly paired in all compounds.","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575849","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}
Konstantin Renner, Fabian Eustermann, Oliver Niehaus, Oliver Janka
Members of the solid solutions CePt1–xAuxAl have been synthesized from the elements and pure samples could be obtained for the whole range of x from 0.1–0.9. Powder X-ray diffraction patterns indicated the TiNiSi-type structure (orthorhombic, space group Pnma) for the whole series, consistent with the end members CePtAl and CeAuAl. The lattice parameters and therefore also the unit cell volumes evolve in a linear fashion when going from CePtAl to CeAuAl. Magnetic susceptibility and magnetization investigations were performed for the compounds with x = 0.1, 0.2, 0.3, 0.5, 0.7 and 0.9. The results show that the ferromagnetic ground state of CePtAl gets destabilized for small degrees of substitution (x = 0.1) resulting in a lower Curie temperature. For larger values of x, changes towards an antiferromagnetic ground state are observed, in line with pure CeAuAl.
从这些元素中合成了固溶体 CePt1-x Au x Al，并在 0.1-0.9 的整个 x 范围内获得了纯样品。粉末 X 射线衍射图样显示整个系列具有 TiNiSi- 型结构（正交，空间群 Pnma），与最终成员 CePtAl 和 CeAuAl 一致。从 CePtAl 到 CeAuAl，晶格参数以及单胞体积呈线性发展。对 x = 0.1、0.2、0.3、0.5、0.7 和 0.9 的化合物进行了磁感应强度和磁化研究。结果表明，当取代度较小（x = 0.1）时，CePtAl 的铁磁基态会变得不稳定，从而导致居里温度降低。当 x 值越大时，观察到向反铁磁基态的变化，这与纯 CeAuAl 的情况一致。
{"title":"Magnetic properties of the solid solutions CePt1−x Au x Al (x = 0.1–0.9)","authors":"Konstantin Renner, Fabian Eustermann, Oliver Niehaus, Oliver Janka","doi":"10.1515/znb-2024-0040","DOIUrl":"https://doi.org/10.1515/znb-2024-0040","url":null,"abstract":"Members of the solid solutions CePt<jats:sub>1–<jats:italic>x</jats:italic> </jats:sub>Au<jats:sub> <jats:italic>x</jats:italic> </jats:sub>Al have been synthesized from the elements and pure samples could be obtained for the whole range of <jats:italic>x</jats:italic> from 0.1–0.9. Powder X-ray diffraction patterns indicated the TiNiSi-type structure (orthorhombic, space group <jats:italic>Pnma</jats:italic>) for the whole series, consistent with the end members CePtAl and CeAuAl. The lattice parameters and therefore also the unit cell volumes evolve in a linear fashion when going from CePtAl to CeAuAl. Magnetic susceptibility and magnetization investigations were performed for the compounds with <jats:italic>x</jats:italic> = 0.1, 0.2, 0.3, 0.5, 0.7 and 0.9. The results show that the ferromagnetic ground state of CePtAl gets destabilized for small degrees of substitution (<jats:italic>x</jats:italic> = 0.1) resulting in a lower Curie temperature. For larger values of <jats:italic>x</jats:italic>, changes towards an antiferromagnetic ground state are observed, in line with pure CeAuAl.","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141514690","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}
Maximilian Kai Reimann, Wilma Pröbsting, Theresa Block, Rainer Pöttgen
Samples of the solid solution Gd2–xYxCu2Mg (in steps of x = 0.2) were synthesized from the elements in sealed tantalum ampoules in a high-frequency furnace. The polycrystalline samples were characterized by X-ray powder diffraction. The structure of Gd0.988(6)Y1.012(6)Cu2Mg was refined from single-crystal X-ray diffractometer data: Mo2B2Fe type, P4/mbm, a = 762.83(4), c = 375.48(2) pm, wR2 = 0.0277, 285 F2 values and 13 variables. Single-crystal data gave no hint for Gd/Y ordering. All samples behave like Curie-Weiss paramagnets with stable trivalent gadolinium and ferromagnetic ordering at low temperature. Within the solid solution the Curie temperature drops almost linearly from TC = 113.5(1) K for Gd2Cu2Mg to 9.3(1) K for Gd0.2Y1.8Cu2Mg, allowing a precise adjustment of the magnetic ordering temperature through gadolinium spin dilution.
固溶体 Gd2-x Y x Cu2Mg 样品（以 x = 0.2 为步长）是在高频炉中从密封的钽安瓿瓶中的元素合成的。通过 X 射线粉末衍射对多晶样品进行了表征。Gd0.988(6)Y1.012(6)Cu2Mg 的结构是从单晶 X 射线衍射仪数据中提炼出来的：Mo2B2Fe 型，P4/mbm，a = 762.83(4)，c = 375.48(2) pm，wR2 = 0.0277，285 F 2 值和 13 个变量。单晶数据没有提示 Gd/Y 排序。所有样品在低温下都表现为具有稳定三价钆和铁磁有序性的居里-魏斯顺磁体。在固溶体中，居里温度从 Gd2Cu2Mg 的 T C = 113.5(1) K 几乎线性下降到 Gd0.2Y1.8Cu2Mg 的 9.3(1) K，从而可以通过钆自旋稀释精确调节磁有序温度。
{"title":"Gadolinium spin dilution in the ferromagnetic solid solutions Gd2–x Y x Cu2Mg","authors":"Maximilian Kai Reimann, Wilma Pröbsting, Theresa Block, Rainer Pöttgen","doi":"10.1515/znb-2024-0029","DOIUrl":"https://doi.org/10.1515/znb-2024-0029","url":null,"abstract":"Samples of the solid solution Gd<jats:sub>2–<jats:italic>x</jats:italic> </jats:sub>Y<jats:sub> <jats:italic>x</jats:italic> </jats:sub>Cu<jats:sub>2</jats:sub>Mg (in steps of <jats:italic>x</jats:italic> = 0.2) were synthesized from the elements in sealed tantalum ampoules in a high-frequency furnace. The polycrystalline samples were characterized by X-ray powder diffraction. The structure of Gd<jats:sub>0.988(6)</jats:sub>Y<jats:sub>1.012(6)</jats:sub>Cu<jats:sub>2</jats:sub>Mg was refined from single-crystal X-ray diffractometer data: Mo<jats:sub>2</jats:sub>B<jats:sub>2</jats:sub>Fe type, <jats:italic>P</jats:italic>4/<jats:italic>mbm</jats:italic>, <jats:italic>a</jats:italic> = 762.83(4), <jats:italic>c</jats:italic> = 375.48(2) pm, w<jats:italic>R</jats:italic>2 = 0.0277, 285 <jats:italic>F</jats:italic> <jats:sup>2</jats:sup> values and 13 variables. Single-crystal data gave no hint for Gd/Y ordering. All samples behave like Curie-Weiss paramagnets with stable trivalent gadolinium and ferromagnetic ordering at low temperature. Within the solid solution the Curie temperature drops almost linearly from <jats:italic>T</jats:italic> <jats:sub>C</jats:sub> = 113.5(1) K for Gd<jats:sub>2</jats:sub>Cu<jats:sub>2</jats:sub>Mg to 9.3(1) K for Gd<jats:sub>0.2</jats:sub>Y<jats:sub>1.8</jats:sub>Cu<jats:sub>2</jats:sub>Mg, allowing a precise adjustment of the magnetic ordering temperature through gadolinium spin dilution.","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141530727","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}
Although the ability of Lewis acids to initiate oligomerisation or polymerisation of pyrroles and indoles is known, no reliable information was available on the structures of the complexes formed therewith. Using 1H NMR spectroscopy, an attempt has now been made to elucidate the structures of the complexes formed by the treatment of pyrroles and indoles with AlCl3.
{"title":"On the interaction of Lewis acids on pyrroles and indoles","authors":"Horst Hartmann, Jens Schönewerk","doi":"10.1515/znb-2024-0003","DOIUrl":"https://doi.org/10.1515/znb-2024-0003","url":null,"abstract":"Although the ability of Lewis acids to initiate oligomerisation or polymerisation of pyrroles and indoles is known, no reliable information was available on the structures of the complexes formed therewith. Using <jats:sup>1</jats:sup>H NMR spectroscopy, an attempt has now been made to elucidate the structures of the complexes formed by the treatment of pyrroles and indoles with AlCl<jats:sub>3</jats:sub>.","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141505315","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}
Ralf J. C. Locke, Florian Ledderboge, Felix C. Goerigk, Frank C. Zimmer, Thomas Schleid
The new fluoride-containing lanthanoid(III) oxoarsenates(III) with the composition Ln5F3[AsO3]4 (Ln = Eu–Lu) could be obtained through partial metallothermic reduction from mixtures of the corresponding trifluorides (LnF3) and the metals (Ln) with As2O3 upon heating in fused silica ampoules. They all crystallize tetragonally in the space group P4/ncc with lattice parameters ranging from a = 1164.71(8) pm and c = 1097.95(7) pm for Eu5F3[AsO4]4 down to a = 1125.72(8) pm and c = 1061.16(7) pm for Lu5F3[AsO3]4 for Z = 4 as consequence of the lanthanoid contraction. The crystal structure exhibits three positions for the trications occupied by one As3+ and two Ln3+ species. The lanthanoids occur with two different coordination polyhedra consisting of a fluoride-capped oxygen cube [(Ln1)O8F]14− and a bicapped trigonal prism [(Ln2)O6F2]11− of F− and O2− anions. A surprisingly diverse Ln3+ cation coordination for the F− anions is noteworthy, as (F1)− has contact to five, but (F2)− to only two of them. The crystallographically unique As3+ cation is coordinated in a discrete ψ1-tetrahedron [AsO3]3− by three oxygen atoms. The lone-pairs of electrons at the As3+ centers point into empty channels along [001], flanked by four columns of condensed [(Ln1)O8F]14− polyhedra. As rather short oxygen-fluorine distances are present within this structural feature, the absence of (OH)− units apt to replace F− needed to be verified by single-crystal Raman spectroscopy. The composition Ln5F3[AsO3] was also confirmed by electron-beam microprobe (EDXS) measurements and the phase purity of selected samples could be proven by powder X-ray diffractometry (PXRD).
{"title":"The isotypic series of tetragonal lanthanoid(III) fluoride oxoarsenates(III) Ln 5F3[AsO3]4 (Ln = Eu–Lu)","authors":"Ralf J. C. Locke, Florian Ledderboge, Felix C. Goerigk, Frank C. Zimmer, Thomas Schleid","doi":"10.1515/znb-2024-0030","DOIUrl":"https://doi.org/10.1515/znb-2024-0030","url":null,"abstract":"The new fluoride-containing lanthanoid(III) oxoarsenates(III) with the composition <jats:italic>Ln</jats:italic> <jats:sub>5</jats:sub>F<jats:sub>3</jats:sub>[AsO<jats:sub>3</jats:sub>]<jats:sub>4</jats:sub> (<jats:italic>Ln</jats:italic> = Eu–Lu) could be obtained through partial metallothermic reduction from mixtures of the corresponding trifluorides (<jats:italic>Ln</jats:italic>F<jats:sub>3</jats:sub>) and the metals (<jats:italic>Ln</jats:italic>) with As<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> upon heating in fused silica ampoules. They all crystallize tetragonally in the space group <jats:italic>P</jats:italic>4/<jats:italic>ncc</jats:italic> with lattice parameters ranging from <jats:italic>a</jats:italic> = 1164.71(8) pm and <jats:italic>c</jats:italic> = 1097.95(7) pm for Eu<jats:sub>5</jats:sub>F<jats:sub>3</jats:sub>[AsO<jats:sub>4</jats:sub>]<jats:sub>4</jats:sub> down to <jats:italic>a</jats:italic> = 1125.72(8) pm and <jats:italic>c</jats:italic> = 1061.16(7) pm for Lu<jats:sub>5</jats:sub>F<jats:sub>3</jats:sub>[AsO<jats:sub>3</jats:sub>]<jats:sub>4</jats:sub> for <jats:italic>Z</jats:italic> = 4 as consequence of the lanthanoid contraction. The crystal structure exhibits three positions for the trications occupied by one As<jats:sup>3+</jats:sup> and two <jats:italic>Ln</jats:italic> <jats:sup>3+</jats:sup> species. The lanthanoids occur with two different coordination polyhedra consisting of a fluoride-capped oxygen cube [(<jats:italic>Ln</jats:italic>1)O<jats:sub>8</jats:sub>F]<jats:sup>14−</jats:sup> and a bicapped trigonal prism [(<jats:italic>Ln</jats:italic>2)O<jats:sub>6</jats:sub>F<jats:sub>2</jats:sub>]<jats:sup>11−</jats:sup> of F<jats:sup>−</jats:sup> and O<jats:sup>2−</jats:sup> anions. A surprisingly diverse <jats:italic>Ln</jats:italic> <jats:sup>3+</jats:sup> cation coordination for the F<jats:sup>−</jats:sup> anions is noteworthy, as (F1)<jats:sup>−</jats:sup> has contact to five, but (F2)<jats:sup>−</jats:sup> to only two of them. The crystallographically unique As<jats:sup>3+</jats:sup> cation is coordinated in a discrete <jats:italic>ψ</jats:italic> <jats:sup>1</jats:sup>-tetrahedron [AsO<jats:sub>3</jats:sub>]<jats:sup>3−</jats:sup> by three oxygen atoms. The lone-pairs of electrons at the As<jats:sup>3+</jats:sup> centers point into empty channels along [001], flanked by four columns of condensed [(<jats:italic>Ln</jats:italic>1)O<jats:sub>8</jats:sub>F]<jats:sup>14−</jats:sup> polyhedra. As rather short oxygen-fluorine distances are present within this structural feature, the absence of (OH)<jats:sup>−</jats:sup> units apt to replace F<jats:sup>−</jats:sup> needed to be verified by single-crystal Raman spectroscopy. The composition <jats:italic>Ln</jats:italic> <jats:sub>5</jats:sub>F<jats:sub>3</jats:sub>[AsO<jats:sub>3</jats:sub>] was also confirmed by electron-beam microprobe (EDXS) measurements and the phase purity of selected samples could be proven by powder X-ray diffractometry (PXRD).","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141505316","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}
Maximilian Kai Reimann, Jutta Kösters, Tautvydas Bieliauskas, Rainer Pöttgen
The crystal structures of the U3Si2-related intermetallic compounds RE2Pd2Cd (RE = Nd, Sm, Gd, Dy) and RE2Ga2Mg (RE = Tb, Er, Tm, Lu) were studied from single crystal X-ray diffraction data at T = 90 K in order to understand the slightly enhanced U33 displacements of the 2a positions in their room temperature structures. The compounds Sm2Pd2Cd, Gd2Pd2Cd and Dy2Pd2Cd show a decrease of the ratio of U33 to U11 for the cadmium atoms, leading to a more isotropic behavior at low temperature, keeping the P4/mbm space group symmetry. Nd2Pd2Cd shows a translationengleiche symmetry reduction to space group P4bm along with a weak puckering effect with shorter (342.7 pm) and longer (345.7 pm) Cd–Nd distances within the Cd@Nd8 square prisms. This new, non-centrosymmetric superstructure variant was also observed for the magnesium compounds Tb2Ga2.069Mg0.931, Er2Ga2.104Mg0.896, Tm2Ga2.097Mg0.903 and Lu2Ga2.173Mg0.827, which show small degrees of Mg/Ga mixing.
根据单晶 X 射线衍射数据，研究了 U3Si2 相关金属间化合物 RE 2Pd2Cd（RE = Nd、Sm、Gd、Dy）和 RE 2Ga2Mg（RE = Tb、Er、Tm、Lu）在 T = 90 K 时的晶体结构，以了解其室温结构中 2a 位置的 U 33 位移略微增强的情况。Sm2Pd2Cd、Gd2Pd2Cd 和 Dy2Pd2Cd 化合物显示出镉原子的 U 33 与 U 11 之比减小，从而在低温下表现出更大的各向同性，保持了 P4/mbm 空间群对称性。Nd2Pd2Cd 在 Cd@Nd8 方棱柱内的 Cd-Nd 间距较短（342.7 pm）和较长（345.7 pm）时，显示出平移棱对称性降低到 P4bm 空间群，同时出现微弱的起皱效应。在镁化合物 Tb2Ga2.069Mg0.931、Er2Ga2.104Mg0.896、Tm2Ga2.097Mg0.903 和 Lu2Ga2.173Mg0.827 中也观察到了这种新的、非中心对称的超结构变体，它们显示出较小程度的镁/镓混合。
{"title":"The crystal structures of the ternary intermetallics RE 2Pd2Cd (RE = Nd, Sm, Gd, Dy) and RE 2Ga2Mg (RE = Tb, Er, Tm, Lu) at 90 K","authors":"Maximilian Kai Reimann, Jutta Kösters, Tautvydas Bieliauskas, Rainer Pöttgen","doi":"10.1515/znb-2024-0014","DOIUrl":"https://doi.org/10.1515/znb-2024-0014","url":null,"abstract":"The crystal structures of the U<jats:sub>3</jats:sub>Si<jats:sub>2</jats:sub>-related intermetallic compounds <jats:italic>RE</jats:italic> <jats:sub>2</jats:sub>Pd<jats:sub>2</jats:sub>Cd (<jats:italic>RE</jats:italic> = Nd, Sm, Gd, Dy) and <jats:italic>RE</jats:italic> <jats:sub>2</jats:sub>Ga<jats:sub>2</jats:sub>Mg (<jats:italic>RE</jats:italic> = Tb, Er, Tm, Lu) were studied from single crystal X-ray diffraction data at <jats:italic>T</jats:italic> = 90 K in order to understand the slightly enhanced <jats:italic>U</jats:italic> <jats:sub>33</jats:sub> displacements of the 2<jats:italic>a</jats:italic> positions in their room temperature structures. The compounds Sm<jats:sub>2</jats:sub>Pd<jats:sub>2</jats:sub>Cd, Gd<jats:sub>2</jats:sub>Pd<jats:sub>2</jats:sub>Cd and Dy<jats:sub>2</jats:sub>Pd<jats:sub>2</jats:sub>Cd show a decrease of the ratio of <jats:italic>U</jats:italic> <jats:sub>33</jats:sub> to <jats:italic>U</jats:italic> <jats:sub>11</jats:sub> for the cadmium atoms, leading to a more isotropic behavior at low temperature, keeping the <jats:italic>P</jats:italic>4/<jats:italic>mbm</jats:italic> space group symmetry. Nd<jats:sub>2</jats:sub>Pd<jats:sub>2</jats:sub>Cd shows a <jats:italic>translationengleiche</jats:italic> symmetry reduction to space group <jats:italic>P</jats:italic>4<jats:italic>bm</jats:italic> along with a weak puckering effect with shorter (342.7 pm) and longer (345.7 pm) Cd–Nd distances within the Cd@Nd<jats:sub>8</jats:sub> square prisms. This new, non-centrosymmetric superstructure variant was also observed for the magnesium compounds Tb<jats:sub>2</jats:sub>Ga<jats:sub>2.069</jats:sub>Mg<jats:sub>0.931</jats:sub>, Er<jats:sub>2</jats:sub>Ga<jats:sub>2.104</jats:sub>Mg<jats:sub>0.896</jats:sub>, Tm<jats:sub>2</jats:sub>Ga<jats:sub>2.097</jats:sub>Mg<jats:sub>0.903</jats:sub> and Lu<jats:sub>2</jats:sub>Ga<jats:sub>2.173</jats:sub>Mg<jats:sub>0.827</jats:sub>, which show small degrees of Mg/Ga mixing.","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141514691","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}
Two zinc complexes [Zn(LH)2(phen)] (1) and [Zn(L)(H2O)]n (2) (LH− = 2-hydroxy-5-((3-nitrophenyl)azo)-benzoate, phen = 1,10-phenanthroline) were synthesized by hydrothermal methods and characterized by elemental analysis and IR spectroscopy. Complexes 1 and 2 crystallize in mononuclear and polymeric structures, respectively, where ligands L2− are coordinated to the zinc ions via their carboxylate and phenolate groups in η2,μ2,κ2 and η2,μ2,κ1 mode, respectively. Introduction of the auxiliary chelating phen ligand results in the chelation of the zinc ions in 1 through both the phen ligand and the carboxylate group of the first LH− anion assisted further by the monodentate carboxylate group of the second LH− anion. In complex 2 the L2− anions act as tridentate ligands utilizing their carboxylate and phenolate groups to coordinate to three zinc ions. The phenolate oxygen atom bridges two zinc ions resulting in the generation of a layer structure. Fluorescence measurements have indicated that complexes 1 and 2 exhibit similar luminescence emissions around 393 and 387 nm, respectively, which originate from intra-ligand π-π* transitions. The emission intensities were strengthened relative to the sodium complex NaLH owing to the enhancement of the rigidity of the aromatic system through the coordination interactions of the ligands with the more tightly bound zinc ions. Furthermore, the suspension of complex 2 can be used to selectively detect Fe3+ cations via the luminescence quenching process.
{"title":"Hydrothermal syntheses, structures and properties of two zinc complexes based on an azobenzene carboxylate ligand","authors":"Mou-Yi Zhang, Lei Guan","doi":"10.1515/znb-2023-0114","DOIUrl":"https://doi.org/10.1515/znb-2023-0114","url":null,"abstract":"Two zinc complexes [Zn(<jats:italic>L</jats:italic>H)<jats:sub>2</jats:sub>(phen)] (1) and [Zn(<jats:italic>L</jats:italic>)(H<jats:sub>2</jats:sub>O)]<jats:sub> <jats:italic>n</jats:italic> </jats:sub> (2) (<jats:italic>L</jats:italic>H<jats:sup>−</jats:sup> = 2-hydroxy-5-((3-nitrophenyl)azo)-benzoate, phen = 1,10-phenanthroline) were synthesized by hydrothermal methods and characterized by elemental analysis and IR spectroscopy. Complexes 1 and 2 crystallize in mononuclear and polymeric structures, respectively, where ligands <jats:italic>L</jats:italic> <jats:sup>2−</jats:sup> are coordinated to the zinc ions via their carboxylate and phenolate groups in <jats:italic>η</jats:italic> <jats:sup>2</jats:sup>,<jats:italic>μ</jats:italic> <jats:sub>2</jats:sub>,<jats:italic>κ</jats:italic> <jats:sup>2</jats:sup> and <jats:italic>η</jats:italic> <jats:sup>2</jats:sup>,<jats:italic>μ</jats:italic> <jats:sub>2</jats:sub>,<jats:italic>κ</jats:italic> <jats:sup>1</jats:sup> mode, respectively. Introduction of the auxiliary chelating phen ligand results in the chelation of the zinc ions in 1 through both the phen ligand and the carboxylate group of the first <jats:italic>L</jats:italic>H<jats:sup>−</jats:sup> anion assisted further by the monodentate carboxylate group of the second <jats:italic>L</jats:italic>H<jats:sup>−</jats:sup> anion. In complex 2 the <jats:italic>L</jats:italic> <jats:sup>2−</jats:sup> anions act as tridentate ligands utilizing their carboxylate and phenolate groups to coordinate to three zinc ions. The phenolate oxygen atom bridges two zinc ions resulting in the generation of a layer structure. Fluorescence measurements have indicated that complexes 1 and 2 exhibit similar luminescence emissions around 393 and 387 nm, respectively, which originate from intra-ligand π-π<jats:sup>*</jats:sup> transitions. The emission intensities were strengthened relative to the sodium complex Na<jats:italic>L</jats:italic>H owing to the enhancement of the rigidity of the aromatic system through the coordination interactions of the ligands with the more tightly bound zinc ions. Furthermore, the suspension of complex 2 can be used to selectively detect Fe<jats:sup>3+</jats:sup> cations via the luminescence quenching process.","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141505317","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}
Peter Heinrichs, Beate Neumann, Hans-Georg Stammler, Norbert W. Mitzel
The tridentate ligand tris(dimethylphosphanyl-methyl)phenylsilane was prepared by the reaction of phenyltrichlorosilane with three equivalents of dimethylphosphanylmethyl lithium. This ligand and the bifunctional bis(dimethylphosphanylmethyl)dimethylsilane were converted into their corresponding gold(I) chloride complexes with three and two AuCl functions, respectively. The complexes were investigated for their ability to form intra- or intermolecular aurophilic interactions.
{"title":"Bi- and tridentate phosphanegold(I) chloride units linked by organosilane backbones","authors":"Peter Heinrichs, Beate Neumann, Hans-Georg Stammler, Norbert W. Mitzel","doi":"10.1515/znb-2024-0026","DOIUrl":"https://doi.org/10.1515/znb-2024-0026","url":null,"abstract":"The tridentate ligand tris(dimethylphosphanyl-methyl)phenylsilane was prepared by the reaction of phenyltrichlorosilane with three equivalents of dimethylphosphanylmethyl lithium. This ligand and the bifunctional bis(dimethylphosphanylmethyl)dimethylsilane were converted into their corresponding gold(I) chloride complexes with three and two AuCl functions, respectively. The complexes were investigated for their ability to form intra- or intermolecular aurophilic interactions.","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141505318","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}
Ag2CdGeSe4 – a I2-II-IV-VI4 quaternary chalcogenide – was synthesized by a mechanochemical synthesis route with a subsequent annealing step inside of a glass ampoule. Detailed analysis and structural investigation using X-ray powder diffraction (PXRD) indicate that Ag2CdGeSe4 crystallizes in the wurtzstannite-type structure with space group Pmn21. For Rietveld refinements, all cubic diamond/sphalerite- and hexagonal diamond/wurtzite-related structure types including all subgroups of the wurtzstannite-type structure were considered. Quantum-chemical calculations were carried out at density-functional theory (DFT) level. The results do not allow an unambiguous verification of the experimentally observed Ag2CdGeSe4 type, due to the small energy differences between the structures. Comparison of calculated and measured UV/Vis data, however, support the results of the Rietveld refinement.
Ag2CdGeSe4是一种I2-II-IV-VI4四元瑀，是通过机械化学合成路线合成的，随后在玻璃安瓿瓶中进行了退火处理。利用 X 射线粉末衍射（PXRD）进行的详细分析和结构研究表明，Ag2CdGeSe4 结晶为空间群 Pmn21 的钨锡矿型结构。在进行里特维尔德细化时，考虑了所有立方体金刚石/闪长岩和六方体金刚石/钨锰铁矿相关的结构类型，包括钨锰铁矿型结构的所有亚群。量子化学计算是在密度泛函理论（DFT）水平上进行的。由于结构间的能量差异较小，计算结果无法明确验证实验观察到的 Ag2CdGeSe4 类型。然而，计算和测量的紫外/可见光数据的比较支持了里特维尔德细化的结果。
{"title":"Mechanochemical synthesis and structural characterization of the I2-II-IV-VI4 quaternary chalcogenide Ag2CdGeSe4","authors":"Kevin D. Profita, Thomas Bredow, Eva M. Heppke","doi":"10.1515/znb-2023-0113","DOIUrl":"https://doi.org/10.1515/znb-2023-0113","url":null,"abstract":"Ag<jats:sub>2</jats:sub>CdGeSe<jats:sub>4</jats:sub> – a I<jats:sub>2</jats:sub>-II-IV-VI<jats:sub>4</jats:sub> quaternary chalcogenide – was synthesized by a mechanochemical synthesis route with a subsequent annealing step inside of a glass ampoule. Detailed analysis and structural investigation using X-ray powder diffraction (PXRD) indicate that Ag<jats:sub>2</jats:sub>CdGeSe<jats:sub>4</jats:sub> crystallizes in the wurtzstannite-type structure with space group <jats:italic>Pmn</jats:italic>2<jats:sub>1</jats:sub>. For Rietveld refinements, all cubic diamond/sphalerite- and hexagonal diamond/wurtzite-related structure types including all subgroups of the wurtzstannite-type structure were considered. Quantum-chemical calculations were carried out at density-functional theory (DFT) level. The results do not allow an unambiguous verification of the experimentally observed Ag<jats:sub>2</jats:sub>CdGeSe<jats:sub>4</jats:sub> type, due to the small energy differences between the structures. Comparison of calculated and measured UV/Vis data, however, support the results of the Rietveld refinement.","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140830013","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}
Tobias A. Teichtmeister, Alexander Hugo Bernhart, Hubert Huppertz
Orthorhombic crystals of the compounds γ-Eu(BO2)3 and γ-Gd(BO2)3 were obtained by high-pressure/high-temperature syntheses at 10.5 GPa and 1100 and 900 °C, respectively. The structures were solved by single-crystal X-ray diffraction methods. The two compounds crystallize with four formula units per cell in the space group Pca21 (no. 29) with the unit cell parameters a = 18.2729(7), b = 4.4076(2), c = 4.2505(1) Å (Ln = Eu), and a = 18.2591(6), b = 4.4055(1), c = 4.2477(1) Å (Ln = Gd). Their infrared spectra and the luminescence spectrum of γ-Eu(BO2)3 are discussed.
{"title":"High-pressure/high-temperature synthesis, single-crystal structure analysis, and spectroscopic data of γ-Eu(BO2)3 and γ-Gd(BO2)3","authors":"Tobias A. Teichtmeister, Alexander Hugo Bernhart, Hubert Huppertz","doi":"10.1515/znb-2024-0013","DOIUrl":"https://doi.org/10.1515/znb-2024-0013","url":null,"abstract":"Orthorhombic crystals of the compounds <jats:italic>γ</jats:italic>-Eu(BO<jats:sub>2</jats:sub>)<jats:sub>3</jats:sub> and <jats:italic>γ</jats:italic>-Gd(BO<jats:sub>2</jats:sub>)<jats:sub>3</jats:sub> were obtained by high-pressure/high-temperature syntheses at 10.5 GPa and 1100 and 900 °C, respectively. The structures were solved by single-crystal X-ray diffraction methods. The two compounds crystallize with four formula units per cell in the space group <jats:italic>Pca</jats:italic>2<jats:sub>1</jats:sub> (no. 29) with the unit cell parameters <jats:italic>a</jats:italic> = 18.2729(7), <jats:italic>b</jats:italic> = 4.4076(2), <jats:italic>c</jats:italic> = 4.2505(1) Å (<jats:italic>Ln</jats:italic> = Eu), and <jats:italic>a</jats:italic> = 18.2591(6), <jats:italic>b</jats:italic> = 4.4055(1), <jats:italic>c</jats:italic> = 4.2477(1) Å (<jats:italic>Ln</jats:italic> = Gd). Their infrared spectra and the luminescence spectrum of <jats:italic>γ</jats:italic>-Eu(BO<jats:sub>2</jats:sub>)<jats:sub>3</jats:sub> are discussed.","PeriodicalId":23831,"journal":{"name":"Zeitschrift für Naturforschung B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140625824","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}
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