scholarly journals (K,Na)2[AsB6O12]2[B3O3(OH)3], a New Microporous Material, and Its Comparison to Teruggite

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 781
Author(s):  
Yulia A. Pankova ◽  
Sergey V. Krivovichev
Keyword(s):  
Crystal Structure ◽  
Structural Complexity ◽  
Effective Diameter ◽  
The Novel ◽  
Flux Method ◽  
Microporous Material ◽  
Coordination Polyhedra ◽  
Natural Origin ◽  
Formation Conditions ◽  
A Chain

Single crystals of the novel boroarsenate (K,Na)2[As2B12O24][B3O3(OH)3] (I) were obtained using the borax flux method. The crystal structure of I was found to be triclinic, P-1, a = 8.414(5), b = 10.173(6), c = 15.90(1) Å, α = 79.56(1), β = 78.68(1), γ = 70.91(1), V = 1251(1) Å3, Z = 2. The crystal structure of I is based upon the novel [AsB6O12]− microporous boroarsenate framework formed by B and As coordination polyhedra. This framework can be subdivided into borate units that are interlinked by AsO4 tetrahedra. In the case of I, the borate substructure is a chain consisting of triborate rings, ☐2Δ, formed by two (BO3) triangles and one (BO4) tetrahedron connected through shared common oxygen atoms. The chains are extended along [0 1 ¯ 1] and are interlinked by (AsO4) tetrahedra in the [011] direction. As a result, the framework has large channels parallel to [100], having an effective diameter of 4.2 × 5.6 Å2. The channels contain occluded electroneutral ring triborate complexes, [B3O3(OH)3]0, formed by three (BO2(OH−))− triangles sharing common O atoms, as well as K+ and Na+ cations. The triborate [B3O3(OH)3]0 units correspond to similar clusters found in the crystal structure of the α-form of metaboric acid, HBO2. According to information-based complexity calculations, the crystal structure of I should be described as complex, with IG = 5.781 bits/atom and IG,total = 625.950 bits/cell. Teruggite, Ca4Mg[B6As(OH)6O11]2(H2O)14, the only known boroarsenate of natural origin, has almost twice as much information per unit cell, with IG,total = 1201.992 bits/cell. The observed difference in structural complexity between I and teruggite is the consequence of their chemistry (hydration state) and different formation conditions.

Zinc(II) and nickel(II) complexes of 3,5-dimethyl-1-(pyridin-2-yl)-1H-pyrazole: relationship between fluorescence and crystal packing

2021 ◽  
Vol 77 (7) ◽  
Author(s):  
Magdalena Małecka ◽  
Joachim Kusz ◽  
Peter Mayer ◽  
Marta Sobiesiak ◽  
Elzbieta Budzisz
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Coordination Complexes ◽  
Cambridge Structural Database ◽  
Fluorescence Properties ◽  
Coordination Polyhedra ◽  
Distorted Octahedral ◽  
Structural Database ◽  
A Chain ◽  
Chloride Monohydrate

Two novel coordination complexes, namely, dichlorido[3,5-dimethyl-1-(pyridin-2-yl-κN)-1H-pyrazole-κN 2]zinc(II), [ZnCl2(C10H11N3)], 1, and aquachloridobis[3,5-dimethyl-1-(pyridin-2-yl-κN)-1H-pyrazole-κN 2]nickel(II) chloride monohydrate, [NiCl(C10H11N3)(H2O)]Cl·H2O, 2, have been synthesized. The crystal structure analyses revealed that complexes 1 and 2 are mononuclear and have ZnN2Cl2 distorted tetrahedral and NiN4OCl distorted octahedral structures, respectively. Complex 1 displays a dimer in the crystal structure, while complex 2 forms a chain along the [010] direction. The fluorescence properties of both complexes were also investigated. A search of the Cambridge Structural Database for other complexes of the ligand 3,5-dimethyl-1-(pyridin-2-yl)-1H-pyrazole (L) shows that there exist different coordination polyhedra with different arrangements as monomers, dimers and polycyclic structures. Here it has also been demonstrated that there is a relationship between the crystal packing and the fluorescence properties of ZnII and CdII complexes of L.

scholarly journals Extraordinary structural complexity of ilmajokite: a multilevel hierarchical framework structure of natural origin

IUCrJ ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Andrey A. Zolotarev ◽  
Sergey V. Krivovichev ◽  
Fernando Cámara ◽  
Luca Bindi ◽  
Elena S. Zhitova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structural Complexity ◽  
Framework Structure ◽  
X Ray Diffraction ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Hierarchical Framework ◽  
The Third ◽  
Trigonal Prismatic ◽  
Modulation Wavelength

The crystal structure of ilmajokite, a rare Na-K-Ba-Ce-titanosilicate from the Khibiny mountains, Kola peninsula, Russia, has been solved using single-crystal X-ray diffraction data. The crystal structure is based on a 3D titanosilicate framework consisting of trigonal prismatic titanosilicate (TPTS) clusters centered by Ce3+ in [9]-coordination. Four adjacent TPTS clusters are linked into four-membered rings within the (010) plane and connected via ribbons parallel to 101. The ribbons are organized into layers parallel to (010) and modulated along the a axis with a modulation wavelength of csinβ = 32.91 Å and an amplitude of ∼b/2 = 13.89 Å. The layers are linked by additional silicate tetrahedra. Na+, K+, Ba2+ and H2O groups occur in the framework cavities and have different occupancies and coordination environments. The crystal structure of ilmajokite can be separated into eight hierarchical levels: atoms, coordination polyhedra, TPTS clusters, rings, ribbons, layers, the framework and the whole structure. The information-based analysis allows estimation of the complexity of the structure as 8.468 bits per atom and 11990.129 bits per cell. According to this analysis, ilmajokite is the third-most complex mineral known to date after ewingite and morrisonite, and is the most complex mineral framework structure, comparable in complexity to paulingite-(Ca) (11 590.532 bits per cell).

Persuasion: Fellow Creatures

2017 ◽  
Author(s):  
Pam Morris
Keyword(s):  
The Self ◽  
The Novel ◽  
Class Relations ◽  
Narrative Perspective ◽  
Class Hierarchies ◽  
A Chain ◽  
Porous Boundaries

Persuasion overtly foregrounds the self as embodied: physical accidents and sickness are recurrent. Sir Walter Eliot’s belief in the time-defying bodily grace of nobility is subject to Austen’s harshest irony. The transition from vertically ordered place to horizontal space in Persuasion is more extreme than in any other of the completed novels. Anne Elliot’s movement from social exclusiveness to socially inclusive possibility allows Austen to challenge gender and class hierarchies traditionally held to be inborn. Her writerly experimentation expands the possibilities of narrative perspective to encompass the porous boundaries of the physical, the emotional and the rational that constitute any moment of consciousness. Her focalisation techniques in the text look directly towards Woolf’s stylist innovations. A chain of references to guns and shooting gathers into the novel contentious contemporary discursive networks on class relations, notions of masculinity and the nature of creaturely life.

scholarly journals Crystal Chemical Relations in the Shchurovskyite Family: Synthesis and Crystal Structures of K2Cu[Cu3O]2(PO4)4 and K2.35Cu0.825[Cu3O]2(PO4)4

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 807
Author(s):  
Ilya V. Kornyakov ◽  
Sergey V. Krivovichev
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structural Complexity ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Complexity Measures ◽  
X Ray ◽  
The Family ◽  
Similarities And Differences ◽  
Related Compounds

Single crystals of two novel shchurovskyite-related compounds, K2Cu[Cu3O]2(PO4)4 (1) and K2.35Cu0.825[Cu3O]2(PO4)4 (2), were synthesized by crystallization from gaseous phase and structurally characterized using single-crystal X-ray diffraction analysis. The crystal structures of both compounds are based upon similar Cu-based layers, formed by rods of the [O2Cu6] dimers of oxocentered (OCu4) tetrahedra. The topologies of the layers show both similarities and differences from the shchurovskyite-type layers. The layers are connected in different fashions via additional Cu atoms located in the interlayer, in contrast to shchurovskyite, where the layers are linked by Ca2+ cations. The structures of the shchurovskyite family are characterized using information-based structural complexity measures, which demonstrate that the crystal structure of 1 is the simplest one, whereas that of 2 is the most complex in the family.

scholarly journals Some Novel Cobalt Diphenylphosphine Complexes: Synthesis, Characterization, and Behavior in the Polymerization of 1,3-Butadiene

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4067
Author(s):  
Giovanni Ricci ◽  
Giuseppe Leone ◽  
Giorgia Zanchin ◽  
Benedetta Palucci ◽  
Alessandra Forni ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
And Behavior

Some novel cobalt diphenylphosphine complexes were synthesized by reacting cobalt(II) chloride with (2-methoxyethyl)diphenylphosphine, (2-methoxyphenyl)diphenylphosphine, and 2-(1,1-dimethylpropyl)-6-(diphenylphosphino)pyridine. Single crystals suitable for X-ray diffraction studies were obtained for the first two complexes, and their crystal structure was determined. The novel compounds were then used in association with methylaluminoxane (MAO) for the polymerization of 1,3-butadiene, and their behavior was compared with that exhibited in the polymerization of the same monomer by the systems CoCl2(PnPrPh2)2/MAO and CoCl2(PPh3)2/MAO. Some significant differences were observed depending on the MAO/Co ratio used, and a plausible interpretation for such a different behavior is proposed.

scholarly journals Crystal Structure of the Streptomyces coelicolor Sortase E1 Transpeptidase Provides Insight into the Binding Mode of the Novel Class E Sorting Signal

PLoS ONE ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. e0167763 ◽  
Author(s):  
Michele D. Kattke ◽  
Albert H. Chan ◽  
Andrew Duong ◽  
Danielle L. Sexton ◽  
Michael R. Sawaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Streptomyces Coelicolor ◽  
Binding Mode ◽  
The Novel ◽  
Sorting Signal ◽  
Insight Into ◽  
Class E

Structural insights into the novel ARM-repeat protein CTNNBL1 and its association with the hPrp19–CDC5L complex

2014 ◽  
Vol 70 (3) ◽  
pp. 780-788 ◽  
Author(s):  
Jae-Woo Ahn ◽  
Sangwoo Kim ◽  
Eun-Jung Kim ◽  
Yeo-Jin Kim ◽  
Kyung-Jin Kim
Keyword(s):  
Crystal Structure ◽  
The Novel ◽  
Molecular Architecture ◽  
Repeat Protein ◽  
Binding Partner ◽  
Catalytic Activation ◽  
Repeat Structure ◽  
Repeat Domain ◽  
Importin Α ◽  
Structural Insights

The hPrp19–CDC5L complex plays a crucial role during human pre-mRNA splicing by catalytic activation of the spliceosome. In order to elucidate the molecular architecture of the hPrp19–CDC5L complex, the crystal structure of CTNNBL1, one of the major components of this complex, was determined. Unlike canonical ARM-repeat proteins such as β-catenin and importin-α, CTNNBL1 was found to contain a twisted and extended ARM-repeat structure at the C-terminal domain and, more importantly, the protein formed a stable dimer. A highly negatively charged patch formed in the N-terminal ARM-repeat domain of CTNNBL1 provides a binding site for CDC5L, a binding partner of the protein in the hPrp19–CDC5L complex, and these two proteins form a complex with a stoichiometry of 2:2. These findings not only present the crystal structure of a novel ARM-repeat protein, CTNNBL1, but also provide insights into the detailed molecular architecture of the hPrp19–CDC5L complex.

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