Crystal and electronic structure of the new ternary phosphide Ho5Pd19P12

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Olha Zhak ◽  
Oksana Karychort ◽  
Volodymyr Babizhetskyy ◽  
Chong Zheng
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Structure Property Relationships ◽  
Metallic Bonding ◽  
Crystal And Electronic Structure ◽  
Insight Into

Abstract The title compound was prepared from the pure elements by sintering. The crystal structure was investigated by means of powder X-ray diffraction data. Ho5Pd19P12 exhibits the hexagonal Ho5Ni19P12-type structure with space group P 6 ‾ 2 m $P‾{6}2m$ , a = 13.1342(2), c = 3.9839(1) Å, R I = 0.060, R p = 0.080. The crystal structure can be described as a combination of two types of the structural units, [HoPd6P3] and [Ho3Pd10P6], respectively, mutually displaced by 1/2 along the crystallographic c axis. Quantum chemical calculations have been performed to analyze the electronic structure and provide deeper insight into the structure-property relationships. The results of the quantum chemical calculations indicate that the material features metallic bonding between Ho and Pd and covalent bonding between Pd and P.

Influence of Structural Organization On Optical and Transport Properties in Organic Materials

1999 ◽  
Vol 598 ◽  
Author(s):  
J. Cornil ◽  
J.Ph. Calbert ◽  
D. Beljonne ◽  
D.A. Dos Santos ◽  
J.L. Bredas
Keyword(s):  
Transport Properties ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Structural Organization ◽  
Conjugated Oligomers ◽  
Structure Property ◽  
Chain Packing ◽  
Crystalline Phases ◽  
Structure Property Relationships ◽  
Insight Into

ABSTRACTCorrelated quantum-chemical calculations performed on supermolecular structures, i.e., on clusters made of several oligomer chains in interaction, provide insight into structure-property relationships in well-organized molecular films. This supermolecular approach is applied to crystalline phases of two prototypical conjugated oligomers and shows that variations in chain packing can lead to dramatically different optical (Davydov) splittings and carrier mobilities. Optimal chain organizations for various types of devices are discussed.

Structure/Property Relationships of Seashells

2004 ◽  
Vol 844 ◽  
Author(s):  
David J. Scurr ◽  
Stephen J. Eichhorn
Keyword(s):  
Raman Band ◽  
Surface Damage ◽  
Structure Property ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Property Relationships ◽  
Energy Variable ◽  
Insight Into ◽  
Characterisation Techniques ◽  
Scanning Electron

ABSTRACTThis study uses various characterisation techniques on the razor shell (Ensis siliqua), to relate the shell's microstructure to its mechanical properties. Scanning electron microscopy (SEM) has shown that the outer and inner regions of the shell are composed of simple and complex crossed lamellar microstructures respectively. These layers are interspersed by prismatic layers of a completely different crystallographic orientation. Nanoindentation and microhardness measurements have shown that the structure is anisotropic, and Raman band shifts have been observed within these indented/deformed areas of shell, showing that the microstructure deforms rather than generating surface damage. The use of energy variable synchrotron X-ray diffraction has shown that the calcium carbonate crystals of the shell are preferentially orientated as a function of depth and that opposing residual stresses exist at the outer and inner regions of the shell. This study has analysed several microstructural features of the shell and provided an insight into how they prevent failure of the material.

scholarly journals Carborane-Based Carbonic Anhydrase Inhibitors: Insight into CAII/CAIX Specificity from a High-Resolution Crystal Structure, Modeling, and Quantum Chemical Calculations

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Pavel Mader ◽  
Adam Pecina ◽  
Petr Cígler ◽  
Martin Lepšík ◽  
Václav Šícha ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Carbonic Anhydrase ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Computational Analysis ◽  
Structure Modeling ◽  
Carbonic Anhydrases ◽  
Carbonic Anhydrase Inhibitors ◽  
Insight Into

Carborane-based compounds are promising lead structures for development of inhibitors of carbonic anhydrases (CAs). Here, we report structural and computational analysis applicable to structure-based design of carborane compounds with selectivity toward the cancer-specific CAIX isoenzyme. We determined the crystal structure of CAII in complex with 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane at 1.0 Å resolution and used this structure to model the 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane interactions with CAIX. A virtual glycine scan revealed the contributions of individual residues to the energy of binding of 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane to CAII and CAIX, respectively.

scholarly journals Towards low-energy-light-driven bistable photoswitches: ortho-fluoroaminoazobenzenes

2021 ◽  
Author(s):  
Kim Kuntze ◽  
Jani Viljakka ◽  
Evgenii Titov ◽  
Zafar Ahmed ◽  
Elina Kalenius ◽  
...  
Keyword(s):  
Visible Light ◽  
Excited States ◽  
Quantum Chemical ◽  
Low Energy ◽  
Living Systems ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Thermal Stability Of ◽  
Insight Into ◽  
Cis Isomer

Abstract Thermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible-light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure–property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the experimental results with quantum chemical calculations, revealing the nature of low-lying excited states and providing insight into thermal isomerization. The synthesized azobenzenes absorb at up to 600 nm and their thermal cis-lifetimes range from milliseconds to months. The most unique example can be driven from trans to cis with any wavelength from UV up to 595 nm, while still exhibiting a thermal cis-lifetime of 81 days.

scholarly journals Towards low-energy-light-driven bistable photoswitches: ortho-fluoroaminoazobenzenes

2021 ◽  
Author(s):  
Kim Kuntze ◽  
Jani Viljakka ◽  
Evgenii Titov ◽  
Zafar Ahmed ◽  
Elina Kalenius ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Visible Light ◽  
Excited States ◽  
Quantum Chemical ◽  
Low Energy ◽  
Living Systems ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Thermal Stability Of ◽  
Insight Into

AbstractThermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure–property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the experimental results with quantum chemical calculations, revealing the nature of low-lying excited states and providing insight into thermal isomerization. The synthesized azobenzenes absorb at up to 600 nm and their thermal cis-lifetimes range from milliseconds to months. The most unique example can be driven from trans to cis with any wavelength from UV up to 595 nm, while still exhibiting a thermal cis-lifetime of 81 days. Graphical abstract

Molecular and Crystal Structure of Chlorido[2-(N,N,N',N'- tetramethylamidinio)ethynido]silver

2013 ◽  
Vol 68 (5-6) ◽  
pp. 687-692
Author(s):  
Werner Weingärtner ◽  
Gerhard Maas
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Diffraction Analysis ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Silver Complex ◽  
State Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths

The solid-state structure of chlorido[2-(N,N,N',N'-tetramethylamidinio)ethynido]silver (3), obtained by C(sp)-metalation of N,N,N',N'-tetramethyl-propiolamidinium chloride with silver(I) oxide, has been determined by X-ray diffraction analysis. A comparison of bond lengths in the propiolamidinium moiety with those of the two genuine propiolamidinium salts 4 and 5, as well as with data for the isolated N,N,N',N'-tetramethyl-propiolamidinium cation obtained by quantum-chemical calculations, has been made. It can be concluded that complex 3 is better described as a (tetramethylamidinio) ethynyl than as a 3,3-bis(dimethylamino)allenylidene silver complex

scholarly journals Preparation and Single Crystal Structure Determination of the First Biobased Furan-Polydiacetylene Using Topochemical Polymerization

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 448 ◽  
Author(s):  
Yves L. Dory ◽  
Mia Caron ◽  
Vincent Olivier Duguay ◽  
Lucas Chicoine-Ouellet ◽  
Daniel Fortin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Geometrical Parameters ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Topochemical Polymerization ◽  
Structure Property Relationships ◽  
Self Assembling ◽  
The Ideal

Crystal structure elucidations of bio-based polymers provide invaluable data regarding structure–property relationships. In this work, we achieved synthesis and Single Crystal X-ray Diffraction (SCXRD) structural determination of a new furan-based polydiacetylene (PDA) derivative with carbamate (urethane) functionality. Firstly, diacetylene (DA) monomers were found to self-assemble in the crystalline state in such a way that the polymerization theoretically occurred in two different directions. Indeed, for both directions, geometrical parameters for the reactive alignment of DA are satisfied and closely related with the optimal geometrical parameters for DA topochemical polymerization (d(1) = 4.7–5.2 Å, d(2) ≤ 3.8 Å, θ ≈ 45°). However, within the axis of hydrogen bonds (HB), the self-assembling monomers display distances and angles (d(1) = 4.816 Å, d(2) = 3.822 Å, θ = 51°) that deviate more from the ideal values than those in the perpendicular direction (d(1) = 4.915Å, d(2) = 3.499Å, θ ≈ 45°). As expected from these observations, the thermal topochemical polymerization occurs in the direction perpendicular to the HB and the resulting PDA was characterized by SCXRD.

Charge Transport Properties in Discotic Liquid Crystals:  A Quantum-Chemical Insight into Structure−Property Relationships

2004 ◽  
Vol 126 (10) ◽  
pp. 3271-3279 ◽  
Author(s):  
Vincent Lemaur ◽  
Demetrio A. da Silva Filho ◽  
Veaceslav Coropceanu ◽  
Matthias Lehmann ◽  
Yves Geerts ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Charge Transport ◽  
Transport Properties ◽  
Quantum Chemical ◽  
Discotic Liquid Crystals ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Insight Into

scholarly journals Crystal structure, electronic structure, temperature-dependent optical and scintillation properties of CsCe2Br7

2015 ◽  
Vol 3 (43) ◽  
pp. 11366-11376 ◽  
Author(s):  
Yuntao Wu ◽  
Hongliang Shi ◽  
Bryan C. Chakoumakos ◽  
Mariya Zhuravleva ◽  
Mao-Hua Du ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Single Crystal ◽  
Point Defects ◽  
Thermal Quenching ◽  
Structure Property ◽  
Temperature Dependent ◽  
Structure Property Relationships ◽  
Crystal Scintillator

The structure–property relationships, thermal quenching, and point defects in CsCe2Br7 single-crystal scintillator were comprehensively studied.

scholarly journals Mono BN-substituted analogues of naphthalene: a theoretical analysis of the effect of BN position on stability, aromaticity and frontier orbital energies

2018 ◽  
Vol 42 (15) ◽  
pp. 12968-12976 ◽  
Author(s):  
Milovan Stojanović ◽  
Marija Baranac-Stojanović
Keyword(s):  
Electronic Structure ◽  
Theoretical Analysis ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Frontier Orbital ◽  
Orbital Energies ◽  
Structure Changes ◽  
Insight Into

An insight into the electronic structure changes driven by CC → BN substitution in a naphthalene system has been given by quantum chemical calculations.

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