A Layered Tungstic Acid H2W2O7·nH2O with a Double-Octahedral Sheet Structure:  Conversion Process from an Aurivillius Phase Bi2W2O9and Structural Characterization

2003 ◽  
Vol 42 (14) ◽  
pp. 4479-4484 ◽  
Author(s):  
Manabu Kudo ◽  
Hajime Ohkawa ◽  
Wataru Sugimoto ◽  
Nobuhiro Kumada ◽  
Zheng Liu ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Tungstic Acid ◽  
Conversion Process ◽  
Aurivillius Phase ◽  
Octahedral Sheet ◽  
Sheet Structure

Mitridatite, Ca6(H2O)6[Fe93+O6(PO4)9].3H2O. A noteworthy octahedral sheet structure

1977 ◽  
Vol 16 (5) ◽  
pp. 1096-1106 ◽  
Author(s):  
Paul Brian. Moore ◽  
Takaharu. Araki
Keyword(s):  
Octahedral Sheet ◽  
Sheet Structure

Synthesis and structure refinement of a new type of layered intergrowth phase: Sb3+x Nb3−x TiO14 and Sb3+x Ta3−x TiO14

1996 ◽  
Vol 52 (6) ◽  
pp. 932-938 ◽  
Author(s):  
C. D. Ling ◽  
S. Schmid ◽  
J. G. Thompson ◽  
R. L. Withers ◽  
M. Sterns
Keyword(s):  
Electron Diffraction ◽  
Structural Characterization ◽  
Structure Refinement ◽  
Aurivillius Phase ◽  
New Type

Attempts to synthesize Sb-based analogues of the known Bi-based Aurivillius phase, Bi3TiNbO9, have led to the discovery of an isomorphous pair of a new type of layered intergrowth phase of general stoichiometry Sb3+x Nb3−x TiO14 and Sb3+x Ta3−x TiO14. Electron diffraction proved essential for the initial recognition and structural characterization of these phases. The structures of Sb3+x Nb3−x TiO14, x = 0.89, and Sb3+x Ta3−x TiO14, x = 1.26, are reported. The structures are described as ordered intergrowths of β-Sb2O4-type and Sb2O5-type structures, with NbV/TaV substituting for SbV in the former and NbV/TaV/TiIV substituting for SbV in the latter.

Synthesis and structural characterization of a novel copper(II)/lead(II) heterometallic organic–inorganic hybrid

2015 ◽  
Vol 70 (9) ◽  
pp. 617-623 ◽  
Author(s):  
Gao-Feng Wang ◽  
Xiao Zhang ◽  
Shu-Wen Sun ◽  
Chen-Zhong Yao ◽  
Zhao-Rong Liu ◽  
...  
Keyword(s):  
Elemental Analysis ◽  
Structural Characterization ◽  
Building Blocks ◽  
Title Complex ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Sheet Structure ◽  
Terpyridine Ligands

AbstractA new copper(II)/lead(II) complex [(terpy)3CuPb5Br12] (1) (terpy = 2,2′:6′,2″-terpyridine) has been synthesized and characterized by IR, elemental analysis, and single-crystal X-ray diffraction analysis. The copper(II) and lead(II) ions in the title complex are in distorted six- (Cu(II), Pb(II)) and eight-fold (Pb(II)) coordination environments, in which the donor atoms are provided by bromide anions and nitrogen atoms of the 2,2′:6′,2″-terpyridine ligands. Complex 1 contains [(terpy)4Pb9Br20]2– building blocks. These bromoplumbate(II) clusters are connected by (terpy)2Cu2Br4 units along the crystallographic b axis and by PbBr6 units along the a axis, thereby forming an extended sheet structure.

Mitridatite: a remarkable octahedral sheet structure

1977 ◽  
Vol 41 (320) ◽  
pp. 527-528 ◽  
Author(s):  
Paul Brian Moore ◽  
Takaharu Araki
Keyword(s):  
Octahedral Sheet ◽  
Sheet Structure

scholarly journals Structural Characterization of Octahedral Sheet in Dioctahedral Smectites by Thermal Analysis

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 347
Author(s):  
Xiaoli Wang ◽  
Yan Li ◽  
Hejing Wang
Keyword(s):  
Thermal Analysis ◽  
Structural Characterization ◽  
Iron Content ◽  
Octahedral Sheet ◽  
Wide Range ◽  
Cis And Trans ◽  
Octahedral Cations ◽  
Derivative Thermogravimetry ◽  
Main Factor

The structures of octahedral sheets of dioctahedral phyllosilicates show cis-vacant (cv) and trans-vacant (tv) configurations due to the different distributions of the octahedral cations over cis- and trans-sites. On the basis of the different dehydroxylation temperatures, a thermal analysis is an effective method used to identify the cv and tv configurations of an octahedral sheet in dioctahedral smectites. The proportions of cv and tv configurations were determined by fitting the derivative thermogravimetry (DTG) curves. A wide range of cv and tv proportions were detected in the samples. The dehydroxylation temperatures of samples consisting of cv configuration are about 150 to 200 °C higher than those consisting of tv configurations. The samples were classified as tv varieties when octahedral Fe3+ > 0.46 mol/FU, and the pure tv dioctahedral smectites were found when Fe3+ > 1.8 mol/FU. A clear linear relationship was found between the content of octahedral Fe3+ and Al3+ and the proportion of cv and tv configurations. The substitution of Al3+ by Fe3+ in the octahedral sheets is the main factor for the formation of tv varieties. There was no relationship detected between the layer charge density, octahedral Mg2+ content, and the proportion of tv and cv. The present results indicate that the iron content has a significant effect on the structure of the octahedral sheet.

Phase behavior of cationic and anionic surfactants at low concentrations

1992 ◽  
Vol 50 (1) ◽  
pp. 694-695
Author(s):  
E. Naranjo
Keyword(s):  
Phase Behavior ◽  
Structural Characterization ◽  
Dynamic Systems ◽  
Anionic Surfactants ◽  
Intermolecular Forces ◽  
Stable Form ◽  
Surfactant Mixtures ◽  
Low Concentrations ◽  
Cationic And Anionic Surfactants ◽  
General Method

Equilibrium vesicles, those which are the stable form of aggregation and form spontaneously on mixing surfactant with water, have never been demonstrated in single component bilayers and only rarely in lipid or surfactant mixtures. Designing a simple and general method for producing spontaneous and stable vesicles depends on a better understanding of the thermodynamics of aggregation, the interplay of intermolecular forces in surfactants, and an efficient way of doing structural characterization in dynamic systems.

New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 582-583
Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Structural Characterization ◽  
Negative Staining ◽  
Low Speed ◽  
Thin Sectioning ◽  
Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

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