scholarly journals Giant single-crystal-to-single-crystal transformations associated with chiral interconversion induced by elimination of chelating ligands

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yun Li ◽  
Bo Zhao ◽  
Jin-Peng Xue ◽  
Jing Xie ◽  
Zi-Shuo Yao ◽  
...  
Keyword(s):  
Structural Change ◽  
Single Crystal ◽  
Single Crystals ◽  
Structural Changes ◽  
Three Dimensional ◽  
Solid State Reaction Method ◽  
Great Promise ◽  
Chelating Ligands ◽  
Crystal Lattices ◽  
Chiral Compounds

AbstractNumerous single crystals that exhibit single-crystal-to-single-crystal (SCSC) transformations have been reported, and some of them show great promise for application to advanced adsorption materials, magnetic switches, and smart actuators. However, the development of single crystals with super-adaptive crystal lattices capable of huge and reversible structural change remains a great challenge. In this study, we report a ZnII complex that undergoes giant SCSC transformation induced by a two-step thermal elimination of ethylene glycol chelating ligands. Although the structural change is exceptionally large (50% volume shrinkage and 36% weight loss), the single-crystal nature of the complex persists because of the multiple strong hydrogen bonds between the constituent molecules. This allows the reversible zero-dimensional to one-dimension and further to three-dimensional structural changes to be fully characterized by single-crystal X-ray diffraction analyses. The elimination of chelating ligands induces a chiral interconversion in the molecules that manifests as a centric-chiral-polar symmetric variation of the single crystal. The study not only presents a unique material, featuring both a periodic crystal lattice and gel-like super-ductility, but also reveals a possible solid-state reaction method for preparing chiral compounds via the elimination of chelating ligands.

Sr4Pt10In21 – the first representative of the Ho4Ni10In21 type with a divalent cation

2019 ◽  
Vol 74 (5) ◽  
pp. 443-449 ◽  
Author(s):  
Birgit Heying ◽  
Jutta Kösters ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Glassy Carbon ◽  
Divalent Cation ◽  
High Frequency ◽  
Three Dimensional ◽  
X Ray ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

AbstractRod-shaped single crystals of Sr4Pt10In21were prepared from the elements in glassy-carbon crucibles in a high-frequency furnace. The structure of Sr4Pt10In21was refined from single-crystal X-ray diffractometer data:C2/m, Ho4Ni10Ga21type,a = 2322.62(7),b = 450.27(2),c = 1958.09(7) pm,β = 133.191(3)°,wR = 0.0464, 3200F2values and 107 variables. The three-dimensional [Pt10In21]δ−polyanionic network is stabilized through substantial Pt–In (269–313 pm Pt–In) and In–In (294–362 pm In–In) bonding. All platinum atoms have slightly distorted tri-capped trigonal prismatic coordination and the two crystallographically independent strontium atoms are located in penta-capped pentagonal prisms.

The Stannides EuPdSn and EuPtSn

1996 ◽  
Vol 51 (6) ◽  
pp. 806-810 ◽  
Author(s):  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Three Dimensional ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

Abstract EuPdSn and EuPtSn were prepared from the elements in tantalum tubes at 1070 K and investigated by X-ray diffraction on both powder as well as single crystals. They crystallize with the TiNiSi type structure of space group Pnma and with Z = 4 formula units per cell. Both structures were refined from single-crystal diffractometer data: a = 751.24(9), b = 469.15(6), c = 804.31(9) pm, V = 0.2835(1) nm3 for EuPdSn, and a = 753.38(7), b = 467.72(4), c = 793.08(7) pm, V = 0.2795(1) nnr for EuPtSn. The structures consist of three-dimensional [PdSn] and [PtSn] polyanionic networks in which the europium atoms are embedded. The crystal chemistry of these stannides is briefly discussed

Single-crystal x-ray diffraction structures of covalent organic frameworks

Science ◽  
2018 ◽  
Vol 361 (6397) ◽  
pp. 48-52 ◽  
Author(s):  
Tianqiong Ma ◽  
Eugene A. Kapustin ◽  
Shawn X. Yin ◽  
Lin Liang ◽  
Zhengyang Zhou ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
General Procedure ◽  
Three Dimensional ◽  
Electron Diffraction Data ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray

The crystallization problem is an outstanding challenge in the chemistry of porous covalent organic frameworks (COFs). Their structural characterization has been limited to modeling and solutions based on powder x-ray or electron diffraction data. Single crystals of COFs amenable to x-ray diffraction characterization have not been reported. Here, we developed a general procedure to grow large single crystals of three-dimensional imine-based COFs (COF-300, hydrated form of COF-300, COF-303, LZU-79, and LZU-111). The high quality of the crystals allowed collection of single-crystal x-ray diffraction data of up to 0.83-angstrom resolution, leading to unambiguous solution and precise anisotropic refinement. Characteristics such as degree of interpenetration, arrangement of water guests, the reversed imine connectivity, linker disorder, and uncommon topology were deciphered with atomic precision—aspects impossible to determine without single crystals.

Rhodium-rich silicides RERh6Si4 (RE=La, Nd, Tb, Dy, Er, Yb)

2017 ◽  
Vol 72 (11) ◽  
pp. 775-780
Author(s):  
Daniel Voßwinkel ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Single Crystals ◽  
Three Dimensional ◽  
X Ray ◽  
Arc Melting ◽  
Covalently Bonded ◽  
Reactive Flux ◽  
The Rare Earth

AbstractPolycrystalline RERh6Si4 (RE=La, Nd, Tb, Dy, Er, Yb) samples can be synthesized by arc-melting of the elements. Single crystals of LaRh6Si4, NdRh6Si4 and YbRh6Si4 were synthesized from the elements in bismuth fluxes (non-reactive flux medium). The structures were refined on the basis of single-crystal X-ray diffractometer data: LiCo6P4 type, P6̅m2, a=700.56(3), c=380.55(1) pm, wR2=0.0257, 317 F2 values, 19 variables for LaRh6Si4, a=698.4(5), c=377.7(2) pm, wR2=0.0578, 219 F2 values, 19 variables for NdRh6Si4 and a=696.00(3), c=371.97(1) pm, wR2=0.0440, 309 F2 values, 19 variables for YbRh6Si4. The rhodium and silicon atoms build up three-dimensional, covalently bonded [Rh6Si4]δ− polyanionic networks with Rh–Si distances ranging from 239 to 249 pm. The rare earth atoms fill larger cavities within channels of these networks and they are coordinated by six silicon and twelve rhodium atoms in the form of hexa-capped hexagonal prisms.

Lead-flux Growth of Eu4Ir8As7 Crystals

2013 ◽  
Vol 68 (11) ◽  
pp. 1185-1190 ◽  
Author(s):  
Ulrike Pfannenschmidt ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Three Dimensional ◽  
Flux Growth ◽  
Tetrahedral Coordination ◽  
X Ray ◽  
Coordination Numbers ◽  
Covalently Bonded ◽  
The Eu

Single crystals of the new arsenide Eu4Ir8As7 were grown from a lead flux. The structure was refined on the basis of single-crystal X-ray diffractometer data: Ca4Ir8P7 type, P21=m, a=1311.3(1), b = 408:4(1), c = 1360:3(1) pm, β = 98:45(1)°, wR2=0.0640, 1985 F2 values, 95 variables. The iridium and arsenic atoms in the Eu4Ir8As7 structure build up a complex three-dimensional, covalently bonded [Ir8As7] network with Ir-As distances ranging from 239 to 260 pm. Each iridium atom has three or four arsenic neighbors in slightly distorted trigonal-planar or tetrahedral coordination. The four crystallographically independent europium atoms fill cavities of coordination numbers 12, 13, and 15 (2) within the [Ir8As7] network. Parts of the Eu4Ir8As7 structure resemble known simpler structure types, and one can describe the Eu4Ir8As7 structure as an intergrowth variant of CaBe2Ge2-, TiNiSi- and AlB2-related slabs.

Synthesis and Structure of NbPdSi

2006 ◽  
Vol 61 (3) ◽  
pp. 339-341 ◽  
Author(s):  
Martin Valldor ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Induction Furnace ◽  
Three Dimensional ◽  
X Ray

Abstract The new silicide NbPdSi was prepared by melting the elements in an arc-furnace.Well-shaped single crystals were obtained by annealing the sample in an induction furnace. The structure of NbPdSi has been studied by X-ray powder and single crystal diffractometer data: TiNiSi type, Pnma, Z = 4, a=643.0(1), b=376.7(1), c=744.4(2) pm, wR2=0.0330, 346 F2 values, and 20 variables. The palladium and silicon atoms build up a three-dimensional [PdSi] network where each palladium atoms has a strongly distorted tetrahedral silicon coordination at Pd-Si ranging from 242 to 250 pm. The niobium atoms fill channels left in the [PdSi] network.

Tuning the surface structure and conductivity of niobium-doped rutile TiO2 single crystals via thermal reduction

2017 ◽  
Vol 19 (45) ◽  
pp. 30339-30350 ◽  
Author(s):  
D. Wrana ◽  
C. Rodenbücher ◽  
M. Krawiec ◽  
B. R. Jany ◽  
J. Rysz ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Structural Changes ◽  
High Vacuum ◽  
Thermal Reduction ◽  
Ultra High Vacuum ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Systematic Exploration ◽  
Niobium Doped

We report on the systematic exploration of electronic and structural changes of Nb-doped rutile TiO2(110) single crystal surfaces due to the thermoreduction under ultra-high vacuum conditions (without sputtering), with comparison to undoped TiO2(110) crystals.

Modern Techniques for Automated Acquiring and Processing Data of Diffraction Electron Microscopy for Nano-Materials and Single-Crystals

2020 ◽  
Vol 992 ◽  
pp. 907-915 ◽  
Author(s):  
V. Sydorets ◽  
O. Berdnikova ◽  
Ye. Polovetskyi ◽  
Ye. Titkov ◽  
A. Bernatskyi
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Single Crystals ◽  
Three Dimensional ◽  
Modern Science ◽  
Nano Materials ◽  
Modern Computer ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Misorientation Angles

Progress in modern science and technology is impossible without the use of new materials, which include nanoparticles and single crystals. Existing approaches in the field of computer vision are difficult to apply to the processing of diffraction patterns, which contain information about the parameters of the fine structure of nanostructured and single-crystal materials. The aim of the work was to develop modern computer-aided techniques that, interacting with the software of the electron microscope, automatically receive and process the information contained in electron diffraction patterns. Replacing the diffraction pattern obtained by a transmission electron microscope with a three-dimensional relief makes it possible to reduce the problem to the solution of the optimization problem. This approach allows not only automating the process of scientific research, but also significantly reduces the time for obtaining the result and increases its accuracy. The application of the proposed approach is demonstrated in measuring the misorientation angles of large single-crystal tungsten ingots, which are obtained by the plasma-induction growing technology.

Investigation of Three-Dimensional Stress Fields and Slip Systems for fcc Single-Crystal Superalloy Notched Specimens

2005 ◽  
Vol 127 (3) ◽  
pp. 629-637 ◽  
Author(s):  
Nagaraj K. Arakere ◽  
Shadab Siddiqui ◽  
Shannon Magnan ◽  
Fereshteh Ebrahimi ◽  
Luis E. Forero
Keyword(s):  
Plastic Deformation ◽  
Plastic Zone ◽  
Single Crystal ◽  
Single Crystals ◽  
Crystallographic Orientation ◽  
Elastic Anisotropy ◽  
Three Dimensional ◽  
Stress Fields ◽  
Slip Systems ◽  
Zone Formation

Metals and their alloys, except for a few intermetallics, are inherently ductile, i.e., plastic deformation precedes fracture in these materials. Therefore, resistance to fracture is directly related to the development of the plastic zone at the crack tip. Recent studies indicate that the fracture toughness of single crystals depends on the crystallographic orientation of the notch as well as the loading direction. In general, the dependence of crack propagation resistance on crystallographic orientation arises from the anisotropy of (i) elastic constants, (ii) plastic deformation (or slip), and (iii) the weakest fracture planes (e.g., cleavage planes). Because of the triaxial stress state at the notch tips, many slip systems that otherwise would not be activated during uniaxial testing become operational. The plastic zone formation in single crystals has been tackled theoretically by Rice and his co-workers [Rice, J. R., 1987, Mech. Mater. 6, pp. 317–335; Rice, J. R., and Saeedvafa, M., 1987, J. Mech. Phys. Solids 36, pp. 189–214; Saeedvafa, M., and Rice, J. R., 1988; ibid., 37, pp. 673–691; Rice, J. R., Hawk, D. E., Asaro, R. J., 1990, Int. J. Fract. 42, pp. 301–321; Saeedvafa, M., and Rice, J. R., 1992, Modell. Simul. Mater. Sci. Eng. 1, pp. 53–71] and only limited experimental work has been conducted in this area. The study of the stresses and strains in the vicinity of a fcc single-crystal notch tip is of relatively recent origin. We present experimental and numerical investigation of three-dimensional (3D) stress fields and evolution of slip sector boundaries near notches in fcc single-crystal PWA1480 tension test specimens and demonstrate that a 3D linear elastic finite element model, which includes the effect of material anisotropy, is shown to predict active slip planes and sectors accurately. The slip sector boundaries are shown to have complex curved shapes with several slip systems active simultaneously near the notch. Results are presented for surface and mid-plane of the specimens. The results demonstrate that accounting for 3D elastic anisotropy is very important for accurate prediction of slip activation near fcc single-crystal notches loaded in tension. Results from the study will help establish guidelines for fatigue damage near single-crystal notches.

Neutronen- und Röntgenbeugungsuntersuchungen an Pulvern und Einkristallen von Strukturverwandten des Berliner Blaus: CsMnIICrIII(CN)6 · D2O , NMe4MnII(Cr0,06,Mn0,94)III(CN)6 · 8 H2O , NMe4MnIICoIII(CN)6 · 8 H20 , Mn3II[MnIII(CN)6]2 · 15 H2O und Cd3[FeIII(CN)6]2 · 15 H2O / Neutron and X-Ray Diffraction Studies on Powders and Single Crystals of Compounds Structurally Related to Prussian Blue: CsMnIICrIII(CN)6 · D2O, NMe4MnII(Cr0,06Mn0,94)III(CN)6 · 8 H2O, NMe4MnIICoIII(CN)6 · 8 H2O, Mn3II[MnIII(CN)6]2 · 15 H2O and Cd3[FeIII(CN)6]2 · 15 H2O

1999 ◽  
Vol 54 (7) ◽  
pp. 870-876 ◽  
Author(s):  
Bernd Ziegler ◽  
Michael Witzel ◽  
Martin Schwarten ◽  
Dietrich Babel
Keyword(s):  
Crystal Structure ◽  
Ambient Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Crystal Structure Refinement ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray

The results of a Rietveld refinement of CsMnCr(CN)6 · D2O neutron powder data (a = 1084.3(1) pm, F4̄3m, Z = 4) and of a neutron single crystal structure refinement of tetragonal NMe4MnII(Cr0,06Mn0,94)III(CN)6 · 8 H2O (a = 1065.8(21), c = 1064.6(26) pm, P4/n, Z = 2) at ambient temperature are reported. Single crystal X-ray analyses of the isostructural octahydrate NMe4MnCo(CN)6 · 8 H20 (a = 1062.1 (1), c = 1046.2( 1) pm) and of gel-grown crystals of cubic Mn3II[MnIII(CN)6]2 - 15 H2O (a = 1062.6(3) pm, Fm3̄m, Z = 4/3) and Cd3[Fe(CN)6]2 · 15 H2O (a = 1067.7(3) pm) were performed as well. The latter “Prussian Blues” are highly disordered and intermediate with respect to cyano-bridging between the above three-dimensional cesium and one-dimensional tetramethylammonium compounds.

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