Bi3+/M2+Oxyphosphate: A Continuous Series of Polycationic Species from the 1D Single Chain to the 2D Planes. Part 1:  From HREM Images to Crystal-Structure Deduction

2006 ◽  
Vol 45 (17) ◽  
pp. 6604-6611 ◽  
Author(s):  
M. Huvé ◽  
M. Colmont ◽  
O. Mentré
Keyword(s):  
Crystal Structure ◽  
Continuous Series ◽  
Single Chain

Building 3D materials from adjustable 2D-units; towards the Design of new Bi-based compounds

2011 ◽  
Vol 1309 ◽  
Author(s):  
M. Colmont ◽  
D. Endara ◽  
M. Huvé ◽  
S.V. Krivovichev ◽  
O. Mentré
Keyword(s):  
Crystal Structure ◽  
Continuous Series ◽  
Infinite Plane ◽  
Single Chain ◽  
Crystallographic Form ◽  
Zinc Compounds

ABSTRACTIn the Bi2O3-MO-P2O5 diagram, on the basis of previous compounds based on 2D-ribbon like units, we have predicted and prepared the infinite term. It contains [Bi2O2]2+ planes arranged within a never-observed crystallographic form. In this series, the ribbons-like units are polycations built on the linkage of n O(Bi,M)4 tetrahedra along their width and infinite in a perpendicular dimension. Hence, this novel form completes the continuous series of analogue compounds, whose building units now extend from the single chain to the infinite plane, via a number of discrete n values (2,3,4,5,6,7,8,9,10,11). The presented materials of formulae Bi4MP2O12 (M= Zn and Mg) roughly show the same crystal structure. However different arrangements of the groups located between the [Bi2O2]2+ planes are at the origin of a complex superstructure in the case of the zinc compounds.

scholarly journals Crystal structure of chain silicate Cs3LuSi3O9

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Hiromitsu Kimura ◽  
Hisanori Yamane
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Title Compound ◽  
Three Dimensional ◽  
Unit Cell ◽  
Single Chain ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Chain Silicate ◽  
A Chain

A caesium lutetium(III) silicate, Cs3LuSi3O9, was synthesized by heating a pelletized mixture of Cs2CO3, Lu2O3 and SiO2 at 1273 K. Single crystals of the title compound were grown in a melted area of the pellet. Cs3LuSi3O9 is a single-chain silicate (orthorhombic space group Pna21) with a chain periodicity of six and is isostructural with Cs3 RE IIIGe3O9 (RE = Pr, Nd and Sm–Yb). The two symmetry-dependent [Si6O18]12− chains in the unit cell lie parallel to the [011] direction. The Lu3+ ions are octahedrally coordinated by O atoms of the silicate chains, generating a three-dimensional framework. Cs+ ions are located in the voids in the framework.

Pb-bearing hollandite-type titanates: A first natural occurrence and reconnaissance synthesis study

2003 ◽  
Vol 67 (5) ◽  
pp. 957-965 ◽  
Author(s):  
E. P. Reguir ◽  
A. R. Chakhmouradian ◽  
R. H. Mitchell
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Electron Microprobe ◽  
Rietveld Method ◽  
Continuous Series ◽  
Natural Occurrence ◽  
Alkaline Complex ◽  
Maximum Proportion ◽  
End Members ◽  
Intermediate Member

AbstractSome samples of hollandite-type titanates from the Murun alkaline complex (Yakutia, Russia) contain appreciable amounts of Pb (up to 12.5 wt.% PbO). These titanates occur in a pegmatitic K-feldsparaegirine rock containing subordinate K-rich batisite, titanite, wadeite and other minerals. The Pb-bearing crystals coexist with hollandite-type phases devoid of detectable Pb and zoned from a Kdominant (priderite) core to a Ba-dominant (henrymeyerite) rim. Recalculation of the microprobe analyses on the stoichiometric basis indicates that most of the Fe occurs in this mineral in trivalent form, suggesting the existence of a solid solution between the Ba(Ti6Fe)O16, K2(Ti6Fe)O16 and Pb(Ti6Fe)O16 end-members. The maximum proportion of the latter end-member in the Murun titanates is ∽45 mol.%. The Ba-free compositions [Pb1.0–1.3(Ti,Fe)8O16] and intermediate members of the (Ba1–xPbx)(Ti6Fe)O16 series were synthesized at 1050 –1100ºC. The synthesis products comprise tetragonal hollandites of various stoichiometry intermixed with rutile, a pseudobrookite-type phase and (for the Ba-free compositions) minor macedonite. Electron microprobe analyses of the hollandites indicate that there is a continuous series of compositions between the two hexatitanate end-members, Ba(Ti6Fe)O16 and Pb(Ti6Fe)O16. The crystal structure of one intermediate member was refined by the Rietveld method in space group I4/m, and found to differ from the hollandite archetype (i.e. Pb-bearing Ba manganate) in that Pb is preferentially partitioned into the 2b tunnel site at (0,0,½), whereas Ba is partitioned into the larger 4e site at (0,0,∽0.8).

scholarly journals Crystal structure of the complex between a single chain antibody and neuraminidase: a basis for rational protein engineering

1993 ◽  
Vol 49 (s1) ◽  
pp. c110-c110
Author(s):  
R. L. Malby ◽  
M. C. Lawrence ◽  
W. R. Tulip ◽  
V. R. Harley ◽  
R. G. Webster ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Protein Engineering ◽  
Single Chain ◽  
Single Chain Antibody

scholarly journals Self-assemblies of γ-CDs with pentablock copolymers PMA-PPO-PEO-PPO-PMA and endcapping via atom transfer radical polymerization of 2-methacryloyloxyethyl phosphorylcholine

2015 ◽  
Vol 11 ◽  
pp. 2267-2277 ◽  
Author(s):  
Jing Lin ◽  
Tao Kong ◽  
Lin Ye ◽  
Ai-ying Zhang ◽  
Zeng-guo Feng
Keyword(s):  
Crystal Structure ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Self Assembly ◽  
Atom Transfer ◽  
Single Chain ◽  
H Nmr ◽  
Pentablock Copolymers ◽  
Dsc Analyses ◽  
Pass Through

Pentablock copolymers PMA-PPO-PEO-PPO-PMA synthesized via atom transfer radical polymerization (ATRP) were self-assembled with varying amounts of γ-CDs to prepare poly(pseudorotaxanes) (PPRs). When the concentration of γ-CDs was lower, the central PEO segment served as a shell of the micelles and was preferentially bent to pass through the γ-CD cavity to construct double-chain-stranded tight-fit PPRs characterized by a channel-like crystal structure. With an increase in the amount of γ-CDs added, they began to accommodate the poly(methyl acrylate) (PMA) segments dissociated from the core of the micelles. When more γ-CDs were threaded and slipped over the segments, the γ-CDs were randomly distributed along the pentablock copolymer chain to generate single-chain-stranded loose-fit PPRs and showed no characteristic channel-like crystal structure. All the self-assembly processes of the pentablock copolymers resulted in the formation of hydrogels. After endcapping via in situ ATRP of 2-methacryloyloxyethyl phosphorylcholine (MPC), these single-chain-stranded loose-fit PPRs were transformed into conformational identical polyrotaxanes (PRs). The structures of the PPRs and PRs were characterized by means of 1H NMR, GPC, 13C CP/MAS NMR, 2D 1H NOESY NMR, FTIR, WXRD, TGA and DSC analyses.

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