Abstract The formation and the stability of a unique intermetallic phase Rh2Cd5 (2:5) that adopts a defect In3Pd5 structure type, has been addressed on the basis of electronic structure calculation and chemical bonding approach. The crystal structures of three closely related phases {RhCd, Rh2Cd5 and Rh3Cd5−δ (δ ∼ 0.56)} in the Rh–Cd binary system are compared. Electronic structure calculations for all these phases reveal that a state-deficient region or pseudogap is opened up near the Fermi level in the electronic density of states.
{"title":"Formation and stability of Rh2Cd5 and its strucural correlation with RhCd and Rh3Cd5−δ (δ ∼ 0.56)","authors":"Nilanjan Roy, B. Koley, Harshit, P. Jana","doi":"10.1515/zkri-2022-0008","DOIUrl":"https://doi.org/10.1515/zkri-2022-0008","url":null,"abstract":"Abstract The formation and the stability of a unique intermetallic phase Rh2Cd5 (2:5) that adopts a defect In3Pd5 structure type, has been addressed on the basis of electronic structure calculation and chemical bonding approach. The crystal structures of three closely related phases {RhCd, Rh2Cd5 and Rh3Cd5−δ (δ ∼ 0.56)} in the Rh–Cd binary system are compared. Electronic structure calculations for all these phases reveal that a state-deficient region or pseudogap is opened up near the Fermi level in the electronic density of states.","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"237 1","pages":"233 - 238"},"PeriodicalIF":1.2,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48200099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Single-crystals of Ca14Al10Zn6O35 suitable for structural investigations were grown from slow cooling of a melt with the same chemical composition in the range between 1300 and 1000 °C. Diffraction experiments performed at ambient temperature yielded the following crystallographic data: space group F23, a = 14.8468 (6) Å, V = 3272.6 (2) Å3, Z = 4. Structure determination and subsequent least‐squares refinements resulted in a residual of R(|F|) = 1.49% for 753 independent observed reflections and 55 parameters. The chiral structure is based on a tetrahedral framework of corner sharing (Zn,Al)O4-tetrahedra. Zn–Al-distributions among the four crystallographically independent T-sites have been studied. A detailed topological analysis based on natural tiles is presented. Actually, the net can be constructed from a total of four different cages (tiles). The largest cavities (face symbol: [316. 616]) have volumes of about 680 Å3 and host [AlO6][Ca14O36] heteropolyhedral clusters consisting of a central [AlO6] – octahedron surrounded by [CaO6]- and [CaO7]-groups. The calcium cations provide linkage to the tetrahedral framework, in other words, the [AlO6]-unit in the barycenter of the cluster is not directly connected to the framework. Furthermore, thermal expansion has been studied in the interval between 25 and 790 °C using in-situ high‐temperature single‐crystal diffraction. No indications for a structural phase transition were observed. From the evolution of the lattice parameters the thermal expansion tensor has been obtained. The response of the structure to variable temperature has been discussed.
采用相同化学成分的熔体在1300 ~ 1000℃范围内缓慢冷却，生长出适合于结构研究的Ca14Al10Zn6O35单晶。在室温下进行的衍射实验得到了以下晶体学数据:空间群F23, a = 14.8468 (6) Å， V = 3272.6 (2) Å3, Z = 4。结构确定和随后的最小二乘改进导致753个独立观测反射和55个参数的残差R(|F|) = 1.49%。手性结构是基于角共享(Zn,Al) o4 -四面体框架。研究了zn - al在四个晶体独立的t位中的分布。对天然瓷砖进行了详细的拓扑分析。实际上，网可以由四个不同的笼子(瓦片)组成。最大的空腔(面符号:[316]。[616])的体积约为680 Å3，宿主[AlO6][Ca14O36]杂多面体团簇由中央[AlO6] -八面体组成，周围是[CaO6]-和[CaO7]-基团。钙离子提供了与四面体框架的连接，换句话说，簇中心的[AlO6]单元并没有直接与框架连接。此外，利用原位高温单晶衍射研究了25 ~ 790°C范围内的热膨胀。没有观察到结构相变的迹象。从晶格参数的演化得到了热膨胀张量。讨论了结构对变温度的响应。
{"title":"High-temperature behavior and structural studies on Ca14Al10Zn6O35","authors":"V. Kahlenberg, H. Krüger","doi":"10.1515/zkri-2022-0014","DOIUrl":"https://doi.org/10.1515/zkri-2022-0014","url":null,"abstract":"Abstract Single-crystals of Ca14Al10Zn6O35 suitable for structural investigations were grown from slow cooling of a melt with the same chemical composition in the range between 1300 and 1000 °C. Diffraction experiments performed at ambient temperature yielded the following crystallographic data: space group F23, a = 14.8468 (6) Å, V = 3272.6 (2) Å3, Z = 4. Structure determination and subsequent least‐squares refinements resulted in a residual of R(|F|) = 1.49% for 753 independent observed reflections and 55 parameters. The chiral structure is based on a tetrahedral framework of corner sharing (Zn,Al)O4-tetrahedra. Zn–Al-distributions among the four crystallographically independent T-sites have been studied. A detailed topological analysis based on natural tiles is presented. Actually, the net can be constructed from a total of four different cages (tiles). The largest cavities (face symbol: [316. 616]) have volumes of about 680 Å3 and host [AlO6][Ca14O36] heteropolyhedral clusters consisting of a central [AlO6] – octahedron surrounded by [CaO6]- and [CaO7]-groups. The calcium cations provide linkage to the tetrahedral framework, in other words, the [AlO6]-unit in the barycenter of the cluster is not directly connected to the framework. Furthermore, thermal expansion has been studied in the interval between 25 and 790 °C using in-situ high‐temperature single‐crystal diffraction. No indications for a structural phase transition were observed. From the evolution of the lattice parameters the thermal expansion tensor has been obtained. The response of the structure to variable temperature has been discussed.","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"237 1","pages":"219 - 232"},"PeriodicalIF":1.2,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46882058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Group–subgroup schemes are a useful tool in crystal chemistry for systemizing crystal structures and they are an indispensable help during X-ray crystallographic studies of complex, twinned and modulated structures. Meanwhile many superstructure variants are summarized within so-called Bärnighausen trees. The present database lists relevant literature with respect to the crystallographic/group-theoretical tools and original work and gives a tabulated overview on the crystallographic fingerprints (aristotype, space group symbol, Pearson code and Wyckoff sequence) of the respective superstructures.
{"title":"Bärnighausen Trees – A group–subgroup reference database","authors":"T. Block, S. Seidel, R. Pöttgen","doi":"10.1515/zkri-2022-0021","DOIUrl":"https://doi.org/10.1515/zkri-2022-0021","url":null,"abstract":"Abstract Group–subgroup schemes are a useful tool in crystal chemistry for systemizing crystal structures and they are an indispensable help during X-ray crystallographic studies of complex, twinned and modulated structures. Meanwhile many superstructure variants are summarized within so-called Bärnighausen trees. The present database lists relevant literature with respect to the crystallographic/group-theoretical tools and original work and gives a tabulated overview on the crystallographic fingerprints (aristotype, space group symbol, Pearson code and Wyckoff sequence) of the respective superstructures.","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"237 1","pages":"215 - 218"},"PeriodicalIF":1.2,"publicationDate":"2022-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45322578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Rosli, N. C. Khalib, K. Thanigaimani, S. Arshad, I. A. Razak
Abstract The 1:1 co-crystals formed between 2-amino-5-chloropyridine/2-amino-5-bromopyridine and isomeric n-methyl-benzoic acids [n = 2, 3 and 4] are described. The co-crystals with the n = 2 co-former are isostructural. The co-formers are linked by intermolecular hydrogen bonds involving amino-N–H⋯O(carbonyl) and hydroxyl-O–H⋯N(pyridine). Additional and comparable amino-N–H⋯O(carbonyl) hydrogen bonds were evident in all co-crystals and play an important role in stabilising the molecular packing. The intermolecular interactions were also analysed through the calculated Hirshfeld surfaces. The charge transfer occurring between the calculated HOMO-LUMO states suggests electron mobility within the co-crystals owing to the aforementioned hydrogen bonding.
{"title":"Structural, Hirshfeld Surface and HOMO-LUMO gap analysis of five co-crystals of 2-amino-5-chloropyridine or 2-amino-bromopyridine with isomeric methylbenzoic acids","authors":"M. Rosli, N. C. Khalib, K. Thanigaimani, S. Arshad, I. A. Razak","doi":"10.1515/zkri-2021-2061","DOIUrl":"https://doi.org/10.1515/zkri-2021-2061","url":null,"abstract":"Abstract The 1:1 co-crystals formed between 2-amino-5-chloropyridine/2-amino-5-bromopyridine and isomeric n-methyl-benzoic acids [n = 2, 3 and 4] are described. The co-crystals with the n = 2 co-former are isostructural. The co-formers are linked by intermolecular hydrogen bonds involving amino-N–H⋯O(carbonyl) and hydroxyl-O–H⋯N(pyridine). Additional and comparable amino-N–H⋯O(carbonyl) hydrogen bonds were evident in all co-crystals and play an important role in stabilising the molecular packing. The intermolecular interactions were also analysed through the calculated Hirshfeld surfaces. The charge transfer occurring between the calculated HOMO-LUMO states suggests electron mobility within the co-crystals owing to the aforementioned hydrogen bonding.","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"237 1","pages":"249 - 258"},"PeriodicalIF":1.2,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48854691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Economics of Aging: New Insights.","authors":"Christine E Bishop","doi":"10.1093/geronb/gbac047","DOIUrl":"10.1093/geronb/gbac047","url":null,"abstract":"","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"229 1","pages":"735-738"},"PeriodicalIF":6.2,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88988698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Gulay, Jutta Kösters, Y. Kalychak, S. Matar, Alfred Rabenbauer, T. Nilges, R. Pöttgen
Abstract CoIn2 (Z. Metallkd. 1970, 61, 342–343) forms by reaction of the elements at 1470 K followed by annealing at 770 K for five days. The room temperature structure is orthorhombic (CuMg2 type, Fddd, a = 529.95(10), b = 940.49(13), c = 1785.8(3) pm, wR2 = 0.0563, 444 F2 values, 17 variables) and shows a phase transition at 195(1) K (DSC data). The low-temperature modification crystallizes in the translationengleiche monoclinic subgroup C2/c and exhibits a new structure type (a = 933.7(7), b = 526.91(10), c = 1000.8(2) pm, β = 117.81(5)°, wR2 = 0.0374, 843 F2 values, 30 variables). The structural phase transition is a consequence of a Peierls type distortion. The equidistant cobalt chains in HT-CoIn2 (270.1 pm, 175.2° Co–Co–Co) show pairwise dislocation in LT-CoIn2 with shorter (252.4 pm) and longer (284.1 pm) Co–Co distances. Each cobalt atom has coordination number 10 in the form of slightly distorted square antiprisms of indium, capped by cobalt on the rectangular faces. Density-of-states calculations reveal metallic behavior for both modifications. Integrated crystal orbital overlap populations featuring the bonding characteristics indicate a slightly higher intensity area for LT-CoIn2 along with a shift to lower energy, manifesting the stabilization by pair formation through Peierls distortion.
摘要:在1470k下反应，在770 K下退火5天，形成了co_2 (Z. Metallkd. 1970, 61, 342-343)。室温结构为正交型(CuMg2型，Fddd, a = 529.95(10)， b = 940.49(13)， c = 1785.8(3) pm, wR2 = 0.0563, 444个F2值，17个变量)，在195(1)K时显示相变(DSC数据)。低温改性在平动英氏单斜亚群C2/c中结晶，呈现出新的结构类型(a = 933.7(7)， b = 526.91(10)， c = 1000.8(2) pm， β = 117.81(5)°，wR2 = 0.03774, F2值843,30个变量)。结构相变是佩尔斯型畸变的结果。ht - co_2中的等距钴链(270.1 pm, 175.2°Co-Co - co)在Co-Co距离较短(252.4 pm)和较长(284.1 pm)的ht - co_2中显示成对位错。每个钴原子的配位数为10，呈轻微扭曲的铟反棱镜方形，矩形面上覆盖着钴。态密度计算揭示了这两种改性的金属行为。具有成键特征的集成晶体轨道重叠居群表明，LT-CoIn2的强度区域略高，并向较低的能量转移，表现出通过佩尔斯畸变形成对的稳定性。
{"title":"Peierls distortion of the cobalt chain in the low-temperature structure of CoIn2","authors":"N. Gulay, Jutta Kösters, Y. Kalychak, S. Matar, Alfred Rabenbauer, T. Nilges, R. Pöttgen","doi":"10.1515/zkri-2022-0020","DOIUrl":"https://doi.org/10.1515/zkri-2022-0020","url":null,"abstract":"Abstract CoIn2 (Z. Metallkd. 1970, 61, 342–343) forms by reaction of the elements at 1470 K followed by annealing at 770 K for five days. The room temperature structure is orthorhombic (CuMg2 type, Fddd, a = 529.95(10), b = 940.49(13), c = 1785.8(3) pm, wR2 = 0.0563, 444 F2 values, 17 variables) and shows a phase transition at 195(1) K (DSC data). The low-temperature modification crystallizes in the translationengleiche monoclinic subgroup C2/c and exhibits a new structure type (a = 933.7(7), b = 526.91(10), c = 1000.8(2) pm, β = 117.81(5)°, wR2 = 0.0374, 843 F2 values, 30 variables). The structural phase transition is a consequence of a Peierls type distortion. The equidistant cobalt chains in HT-CoIn2 (270.1 pm, 175.2° Co–Co–Co) show pairwise dislocation in LT-CoIn2 with shorter (252.4 pm) and longer (284.1 pm) Co–Co distances. Each cobalt atom has coordination number 10 in the form of slightly distorted square antiprisms of indium, capped by cobalt on the rectangular faces. Density-of-states calculations reveal metallic behavior for both modifications. Integrated crystal orbital overlap populations featuring the bonding characteristics indicate a slightly higher intensity area for LT-CoIn2 along with a shift to lower energy, manifesting the stabilization by pair formation through Peierls distortion.","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"237 1","pages":"239 - 248"},"PeriodicalIF":1.2,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42266587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Studying the wave-particle nature of electrons in different ways has lead to many fundamental discoveries. Particularly, the dimensionality dependent electronic behavior in the Luttinger Liquid (1D), Quantum Hall (2D) and non-interacting Fermi Liquid (3D) regimes have already revolutionized our understanding of the mechanisms behind quantum electronics. In this work, the theoretical and experimental studies focus on the non-integer dimension represented by an sp2-carbon-based Sierpinski triangular structure with a 1.58D space occupancy. In the tight-binding approach, the spectral distribution of electronic states of such a structure exhibits distinct peak patterns, which are well-separated by gaps. Through quantum transport simulation, the conductance of electrons in 1.58D was studied. Both delocalized, conducting and localized, non-conducting states identified, which differ from the established features of both the fully 2D graphene sheet and 1D carbon nanotubes. In microwave scattering measurements on an adequate experimental setting and the respective simulations on the Sierpinski triangle, the obtained diffraction patterns showed interesting peculiarities such as a reduced number of minima and magic angle, next to diffraction regions of high and low intensity, as well as forbidden regions. The fractal geometry of the structure affects the propagation of waves by manipulating the way they interact with each other which results in structural metamaterial-like interference characteristics, decreasing or amplifying the transmitted or reflected signals, or blocking the transport completely.
{"title":"Quantum transport and microwave scattering on fractal lattices","authors":"K. Subramaniam, M. Zschornak, S. Gemming","doi":"10.1515/zkri-2021-2070","DOIUrl":"https://doi.org/10.1515/zkri-2021-2070","url":null,"abstract":"Abstract Studying the wave-particle nature of electrons in different ways has lead to many fundamental discoveries. Particularly, the dimensionality dependent electronic behavior in the Luttinger Liquid (1D), Quantum Hall (2D) and non-interacting Fermi Liquid (3D) regimes have already revolutionized our understanding of the mechanisms behind quantum electronics. In this work, the theoretical and experimental studies focus on the non-integer dimension represented by an sp2-carbon-based Sierpinski triangular structure with a 1.58D space occupancy. In the tight-binding approach, the spectral distribution of electronic states of such a structure exhibits distinct peak patterns, which are well-separated by gaps. Through quantum transport simulation, the conductance of electrons in 1.58D was studied. Both delocalized, conducting and localized, non-conducting states identified, which differ from the established features of both the fully 2D graphene sheet and 1D carbon nanotubes. In microwave scattering measurements on an adequate experimental setting and the respective simulations on the Sierpinski triangle, the obtained diffraction patterns showed interesting peculiarities such as a reduced number of minima and magic angle, next to diffraction regions of high and low intensity, as well as forbidden regions. The fractal geometry of the structure affects the propagation of waves by manipulating the way they interact with each other which results in structural metamaterial-like interference characteristics, decreasing or amplifying the transmitted or reflected signals, or blocking the transport completely.","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"237 1","pages":"179 - 190"},"PeriodicalIF":1.2,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45768351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract No scientific model has shaped crystallography as much as the classical nucleation theory (CNT). The majority of all growth processes and particle formation processes are attributed to the CNT. However, alternative descriptions exist that may be better suited to explain material formation under certain conditions. One of these alternatives is the dewetting theory (DWT). To describe the possibilities of DWT in more detail, we selected three material systems for three current application areas: Gold particles on silicon as catalysts for nanowire growth, indium particles on molybdenum as precursor material in novel solar cell concepts, and silicon layers on silicon germanium as potential wells in semiconductor quantum computers. Each of these material systems showed particular advantages of DWT over CNT. For example, the properties of surface particles with high atomic mobility could be described more realistically using DWT. Yet, there were clear indications that the DWT is not yet complete and that further research is needed to complete it. In particular, modern crystallographic challenges could serve this purpose, for example the development of semiconductor quantum computers, in order to re-evaluate known models such as the CNT and DWT and adapt them to the latest state of science and technology. For the time being, this article will give an outlook on the advantages of the DWT today and its potential for future research in crystallography.
{"title":"Leveraging dewetting models rather than nucleation models: current crystallographic challenges in interfacial and nanomaterials research","authors":"O. Ernst, Yujia Liu, T. Boeck","doi":"10.1515/zkri-2021-2078","DOIUrl":"https://doi.org/10.1515/zkri-2021-2078","url":null,"abstract":"Abstract No scientific model has shaped crystallography as much as the classical nucleation theory (CNT). The majority of all growth processes and particle formation processes are attributed to the CNT. However, alternative descriptions exist that may be better suited to explain material formation under certain conditions. One of these alternatives is the dewetting theory (DWT). To describe the possibilities of DWT in more detail, we selected three material systems for three current application areas: Gold particles on silicon as catalysts for nanowire growth, indium particles on molybdenum as precursor material in novel solar cell concepts, and silicon layers on silicon germanium as potential wells in semiconductor quantum computers. Each of these material systems showed particular advantages of DWT over CNT. For example, the properties of surface particles with high atomic mobility could be described more realistically using DWT. Yet, there were clear indications that the DWT is not yet complete and that further research is needed to complete it. In particular, modern crystallographic challenges could serve this purpose, for example the development of semiconductor quantum computers, in order to re-evaluate known models such as the CNT and DWT and adapt them to the latest state of science and technology. For the time being, this article will give an outlook on the advantages of the DWT today and its potential for future research in crystallography.","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"237 1","pages":"191 - 200"},"PeriodicalIF":1.2,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47367310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract An achiral tripeptide, namely, Boc-γ-Abu-m-ABA-Aib-OMe (γ-Abu: γ−amino butyric acid; m-ABA: meta-aminobenzoic acid) was synthesized by solution phase procedure. The α, γ-hybrid peptide was designed in such a way that two dissimilar γ−amino acids, one flexible and another rigid, were positioned sidewise along with α-amino isobutyric acid (Aib) as C-terminal residue. The single crystal X-ray diffraction analysis revealed that two kinks were generated around centrally placed m-ABA. Interestingly, the peptide self-assembled via three intermolecular N–H···O and one intermolecular C–H···O hydrogen bonding interactions to supramlecular helical architecture.
{"title":"Unique supramolecular assembly of a synthetic achiral α, γ-hybrid tripeptide","authors":"Arpita Dutta, Suven Das, Purak Das, Suvendu Maity, P. Ghosh, Soumya Shankha Biswas","doi":"10.1515/zkri-2022-0002","DOIUrl":"https://doi.org/10.1515/zkri-2022-0002","url":null,"abstract":"Abstract An achiral tripeptide, namely, Boc-γ-Abu-m-ABA-Aib-OMe (γ-Abu: γ−amino butyric acid; m-ABA: meta-aminobenzoic acid) was synthesized by solution phase procedure. The α, γ-hybrid peptide was designed in such a way that two dissimilar γ−amino acids, one flexible and another rigid, were positioned sidewise along with α-amino isobutyric acid (Aib) as C-terminal residue. The single crystal X-ray diffraction analysis revealed that two kinks were generated around centrally placed m-ABA. Interestingly, the peptide self-assembled via three intermolecular N–H···O and one intermolecular C–H···O hydrogen bonding interactions to supramlecular helical architecture.","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"237 1","pages":"77 - 81"},"PeriodicalIF":1.2,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47635737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alena Shlyaykher, T. Pippinger, T. Schleid, O. Reckeweg, F. Tambornino
Abstract Colorless rubidium thiocyanate was synthesized by three different approaches. DCS-TGA measurements allowed for extraction of phase transition, melting, and decomposition temperatures. Single-crystal X-ray diffraction showed Rb[SCN] to crystallize in the low-temperature LT-K[SCN] crystal structure type (Pbcm, oP16). Above its phase-transition temperature (432.1 K) the title compound crystallizes with the high-temperature HT-K[SCN] crystal structure type (I4/mcm, tI28) with head-to-tail disordered thiocyanate anions. Both modifications are related to one another and to the LT/HT-Cs[SCN] structure types, and the relation has been studied in detail employing the Bärnighausen formalism. Phase purity and bulk phase transition were confirmed by temperature-dependent PXRD.
{"title":"Syntheses, crystallographic characterization, and structural relations of Rb[SCN]","authors":"Alena Shlyaykher, T. Pippinger, T. Schleid, O. Reckeweg, F. Tambornino","doi":"10.1515/zkri-2022-0015","DOIUrl":"https://doi.org/10.1515/zkri-2022-0015","url":null,"abstract":"Abstract Colorless rubidium thiocyanate was synthesized by three different approaches. DCS-TGA measurements allowed for extraction of phase transition, melting, and decomposition temperatures. Single-crystal X-ray diffraction showed Rb[SCN] to crystallize in the low-temperature LT-K[SCN] crystal structure type (Pbcm, oP16). Above its phase-transition temperature (432.1 K) the title compound crystallizes with the high-temperature HT-K[SCN] crystal structure type (I4/mcm, tI28) with head-to-tail disordered thiocyanate anions. Both modifications are related to one another and to the LT/HT-Cs[SCN] structure types, and the relation has been studied in detail employing the Bärnighausen formalism. Phase purity and bulk phase transition were confirmed by temperature-dependent PXRD.","PeriodicalId":48676,"journal":{"name":"Zeitschrift Fur Kristallographie-Crystalline Materials","volume":"237 1","pages":"69 - 75"},"PeriodicalIF":1.2,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47392844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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