Unusual Fe9 and Fe18 structural types from the use of 2,6-pyridinedimethanol in FeIII cluster chemistry

2010 ◽  
Vol 39 (38) ◽  
pp. 9131 ◽  
Author(s):  
Taketo Taguchi ◽  
Michael S. Thompson ◽  
Khalil A. Abboud ◽  
George Christou
Keyword(s):  
Cluster Chemistry ◽  
Structural Types

Unusual Structural Types in Nickel Cluster Chemistry from the Use of Pyridyl Oximes: Ni5, Ni12Na2, and Ni14Clusters

2008 ◽  
Vol 47 (24) ◽  
pp. 11825-11838 ◽  
Author(s):  
Theocharis C. Stamatatos ◽  
Albert Escuer ◽  
Khalil A. Abboud ◽  
Catherine P. Raptopoulou ◽  
Spyros P. Perlepes ◽  
...  
Keyword(s):  
Cluster Chemistry ◽  
Structural Types ◽  
Nickel Cluster

Macropolyhedral Boron-Containing Cluster Chemistry. A Metallathiaborane from S2B17H17: Isolation and Characterisation of [(PMe2Ph)2PtS2B16H16]; A neo-arachno Ten-Vertex Cluster Shape, and the Constitution of the [arachno-B10H15]- Anion

2005 ◽  
Vol 70 (4) ◽  
pp. 430-440 ◽  
Author(s):  
Michael J. Carr ◽  
Michael G. S. Londesborough ◽  
Jonathan Bould ◽  
Ivana Císařová ◽  
Bohumil Štíbr ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Sodium Hydride ◽  
Hydrogen Atoms ◽  
Subsequent Reaction ◽  
Cluster Chemistry ◽  
Cluster Shape ◽  
Open Face

The deprotonation of S2B17H17 with sodium hydride and subsequent reaction with [PtCl2(PMe2Ph)2] gives the new macropolyhedral metallathiaborane [(PMe2Ph)2PtS2B16H16], of which the cluster consists of a conventional eleven-vertex nido {SB10} unit, fused, with two boron atoms in common, with a {PtSB8} unit of unique ten-vertex neo-arachno constitution and geometry. The latter geometry suggests a configuration for the previously structurally uncharacterised [B10H15]- anion; starting from this configuration, DFT calculations of structure and thence of boron nuclear shieldings, which are found very closely to mimic those found experimentally, thence support a fluxional structure for [B10H15]- with three {BHB(bridging)} and two {BH(endo)} hydrogen atoms around a six-membered open face.

Crystal structure of KBSi3O8 isostructural with danburite

1993 ◽  
Vol 57 (386) ◽  
pp. 157-164 ◽  
Author(s):  
Mitsuyoshi Kimata
Keyword(s):  
Crystal Structure ◽  
Direct Method ◽  
Crystal Chemical ◽  
Chemical Formula ◽  
Crystal Chemical Formula ◽  
3 Dimensional ◽  
Tetrahedral Sites ◽  
Structural Types ◽  
Coupled Substitution ◽  
Insight Into

AbstractThe crystal structure of KBSi3O8 (orthorhombic, Pnam, with a = 8.683(1), b = 9.253(1), c = 8.272(1) Å,, V = 664.4(1) Å3, Z = 4) has been determined by the direct method applied to 3- dimensional rcflection data. The structure of a microcrystal with the dimensions 20 × 29 × 37 μm was refined to an unweightcd residual of R = 0.031 using 386 non-zero structure amplitudes. KBSi3O8 adopts a structure essentially different from recdmergneritc NaBSi3O8, with the low albite (NaAlSi3O8) structure, and isotypic with danburite CaB2Si2Os which has the same topology as paracelsian BaAl2Si2O8. The chenfical relationship between this sample and danburitc gives insight into a new coupled substitution; K+ + Si4+ = Ca2+ + B3+ in the extraframework and tetrahedral sites. The present occupancy refinement revealed partial disordering of B and Si atoms which jointly reside in two kinds of general equivalent points, T(1) and T(2) sites. Thus the expanded crystal-chemical formula can be written in the form K(B0.44Si0.56)2(B0.06Si0.94)2O8The systematic trend among crystalline compounds with the M+T3+T4+3O8 formula suggests that they exist in one of four structural types; the feldspar structures with T3+/T4+ ordered and/or disordered forms, and the paracelsian and the hollandite structures.

SOIL MORPHOLOGY AND SOIL PHYSICAL PROPERTIES. I. SOIL AERATION

1972 ◽  
Vol 52 (3) ◽  
pp. 311-321 ◽  
Author(s):  
K. W. AYRES ◽  
R. G. BUTTON ◽  
E. DE JONG
Keyword(s):  
Soil Structure ◽  
Regression Coefficient ◽  
The Other ◽  
Soil Morphology ◽  
Soil Horizons ◽  
Undisturbed Soil ◽  
Soil Aeration ◽  
Structural Types ◽  
Highly Correlated ◽  
Undisturbed Soil Cores

The relation between soil structure and soil aeration was investigated on undisturbed soil cores from soil horizons exhibiting six distinct kinds of soil structure (prismatic, columnar, blocky, granular, platy, massive) over a broad range of soil texture. Soil aeration was characterized at ⅓ atm suction by measurements of air porosity, relative diffusivity (D/Do) and the rate of oxygen diffusion to a platinum microelectrode (ODR). Aeration was adequate in most of the Chernozemic soil horizons studied; however, aeration in many of the Bnt horizons of the Solonetzic soils was inadequate. Air porosity and D/Do were highly correlated. The regression coefficient for D/Do vs. air porosity for blocky structures was significantly different from that found for the other five structural types. For granular structures a negative correlation was found for ODR vs. air porosity compared with a low positive correlation found for the other structure types.

Oxonol dyes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Heinz Mustroph
Keyword(s):  
Silver Halide ◽  
Medical Diagnostics ◽  
Water Soluble ◽  
Eukaryotic Cells ◽  
Polymethine Dyes ◽  
Technical Application ◽  
Structural Types ◽  
Oxonol Dyes ◽  
Oxygen Atoms

Abstract Oxonol dyes are classified as anionic polymethine dyes, which cover a wide variety of structural types. The name of the class originates from the oxygen atoms which terminate each end of the polymethine chains that form the backbone of their structure. In technically useful dyes, these oxygen atoms tend to be substituents of heterocycles. The main technical application of water soluble oxonol dyes was in silver halide photography as filter dyes and antihalation dyes. Lipophilic oxonol dyes are used in bio-analysis and medical diagnostics to stain cells, bacteria or liposomes for example. Their main bioanalytical usage is in the determination of membrane potentials in eukaryotic cells and prokaryotic bacteria.

Sign in / Sign up

Export Citation Format

Share Document