Thermoinduced Structural-transformation and Luminescent Conversion in Hybrid Manganese Halides

2022 ◽  
Author(s):  
Chunli Jiang ◽  
Qianqian Luo ◽  
Chunhua Luo ◽  
Hechun Lin ◽  
Hui Peng
Keyword(s):  
Crystal Structure ◽  
Water Vapor ◽  
Structural Analysis ◽  
Structural Transformation ◽  
Potential Application ◽  
Organic Ligand ◽  
Heating Treatment ◽  
Crystal Structural ◽  
Insight Into

Abstract We report here the synthesis of hybrid manganese halide crystals, (C4H7N2)MnCl3·H2O and (C4H7N2)2MnCl4, by using the same organic ligand 2-methylimidazole. Upon heating treatment, the red-emissive (C4H7N2)MnCl3·H2O crystal is structurally transformed into green-emissive (C4H7N2)2MnCl4 crystal in situ. The crystal structural analysis reveals that the [MnCl5·H2O]3- octahedra chains decompose into mono [MnCl4]2- tetrahedra, accompanied by the departure of H2O molecules. Upon cooling in air or water vapor, the crystal structure and luminescence of (C4H7N2)2MnCl4 are transformed to those of (C4H7N2)MnCl3·H2O. The in situ conversion of luminescence between (C4H7N2)MnCl3·H2O and (C4H7N2)2MnCl4 provides new insight into the potential application of hybrid manganese halides.

scholarly journals Synthesis, structure, thermal decomposition and spectral properties of neutral [Fe(bpta)2(etOH)2(NCS)2]

2015 ◽  
Vol 8 (1) ◽  
pp. 78-85
Author(s):  
Zuzana Lukačovičová ◽  
Róbert Uhrecký ◽  
Ján Moncoľ ◽  
Darina Lackováa ◽  
Iveta Ondrejkovičová ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Infrared Spectroscopy ◽  
Structural Analysis ◽  
Spectral Properties ◽  
Ethanol Solution ◽  
Single Crystal Diffraction ◽  
Triclinic Space Group ◽  
X Ray

Abstract The new iron(II) complex [Fe(bpta)2(EtOH)2(NCS)2] (bpta = 3,3’-(1,2,4-thiadiazole-3,5-diyl) dipyridine; EtOH = ethanol) has been prepared by refluxing Fe(NCS)3 or Fe(NCS)2 with thionicotinamide in an ethanol solution and characterized by elemental analysis, infrared spectroscopy, thermal decomposition and X-ray structural analysis. The characterized compound is a mixture of three regioisomers resulting from differential coordination by the 3- and 5-position 2-pyridyl groups. The bpta ligand was generated in situ by the oxidation dimerization of thionicotinamide. X-ray single-crystal diffraction revealed that the crystal structure is centrosymmetric and the complex crystallizes in the triclinic space group P-1. The iron(II) atom lies in the centre of symmetry and it is octahedrally coordinated by two nitrogen atoms from two thiocyanate anions and two oxygen atoms from ethanol molecules in the equatorial plane and two nitrogen atoms of pyridine rings from two bpta ligands in the axial positions. This complex represents the second example of metal complex with bpta.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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.

scholarly journals Development of Fragility Curves for Piping and Slope Stability of River Levees

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 738
Author(s):  
Nicola Rossi ◽  
Mario Bačić ◽  
Meho Saša Kovačević ◽  
Lovorka Librić
Keyword(s):  
Slope Stability ◽  
Fragility Curves ◽  
Safety Margin ◽  
Water Levels ◽  
Flood Event ◽  
Soil Parameters ◽  
Design Code ◽  
A Site ◽  
Insight Into

The design code Eurocode 7 relies on semi-probabilistic calculation procedures, through utilization of the soil parameters obtained by in situ and laboratory tests, or by the means of transformation models. To reach a prescribed safety margin, the inherent soil parameter variability is accounted for through the application of partial factors to either soil parameters directly or to the resistance. However, considering several sources of geotechnical uncertainty, including the inherent soil variability, measurement error and transformation uncertainty, full probabilistic analyses should be implemented to directly consider the site-specific variability. This paper presents the procedure of developing fragility curves for levee slope stability and piping as failure mechanisms that lead to larger breaches, where a direct influence of the flood event intensity on the probability of failure is calculated. A range of fragility curve sets is presented, considering the variability of levee material properties and varying durations of the flood event, thus providing crucial insight into the vulnerability of the levee exposed to rising water levels. The procedure is applied to the River Drava levee, a site which has shown a continuous trend of increased water levels in recent years.

Insight into the physics of the 5f -band antiferromagnet U2Ni2Sn from the pressure dependence of crystal structure and electrical resistivity

2021 ◽  
Vol 103 (3) ◽  
Author(s):  
Silvie Maskova-Cerna ◽  
Alexandre Kolomiets ◽  
Jiri Prchal ◽  
Itzhak Halevy ◽  
Volodymyr Buturlim ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrical Resistivity ◽  
Pressure Dependence ◽  
Insight Into
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