The alkaline earth-palladium-germanides Sr3Pd4Ge4 and BaPdGe

2018 ◽  
Vol 73 (3-4) ◽  
pp. 243-250 ◽  
Author(s):  
Sebastian Stein ◽  
Samir F. Matar ◽  
Kai Heinz Schmolke ◽  
Jutta Kösters ◽  
Rainer Pöttgen
Keyword(s):  
Density Functional ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Space Group ◽  
X Ray ◽  
Overlap Population ◽  
The Density Functional Theory ◽  
Structure Investigations

AbstractThe germanides Sr3Pd4Ge4and BaPdGe were obtained from high-temperature reactions in sealed niobium ampoules and their structures have been determined from single-crystal X-ray diffraction data:a=444.2(1),b=438.1(1),c=2472.2(7) pm, space groupImmm, U3Ni4Si4type,wR2=0.0471, 576 unique reflections, 25 parameters for Sr3Pd4Ge4anda=677.09(8), space groupP213, LaIrSi type,wR2=0.0322, 409 unique reflections, nine parameters for BaPdGe. Both germanides have pronounced three-dimensional [Pd4Ge4]δ−and [PdGe]δ−polyanionic networks with Pd–Ge bonding interactions. This is confirmed by the density functional theory (DFT)-based electronic structure investigations, the trends of charge transfer and crystal orbital overlap population (COOP) analyses.

Synthesis of [Re2Cl4(O)2(µ-O)(3,5-lut)4] and investigation of its structure via X-ray and spectroscopic measurements and DFT calculations

2014 ◽  
Vol 68 (5) ◽  
Author(s):  
Sławomir Michalik ◽  
Jan Małecki ◽  
Natalia Młynarczyk
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Computational Study ◽  
Dft Method ◽  
Time Dependent ◽  
Electronic Transitions ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
The Density Functional Theory

AbstractA combined experimental and computational study of the dinuclear rhenium(V) complex containing (ReO)2(µ-O) core is presented in this article. The solid-state [Re2Cl4(O)2(µ-O)(3,5-lut)4] (3,5-lut = 3,5-dimethylpyridine) complex was characterised structurally (by single crystal X-ray diffraction) and spectroscopically (by IR, NMR, UV-VIS). The electronic structure was examined using the density functional theory (DFT) method. The spin-allowed electronic transitions were calculated using the time-dependent DFT method, and the UV-VIS spectrum was discussed.

Crystal Structure, Optical Properties of Molecular Crystals 1, 3-propanediol Bis(4-aminobenzoate)

2014 ◽  
Vol 1052 ◽  
pp. 207-211
Author(s):  
Rui Ting Xue ◽  
Wei Song Sun ◽  
Si Rong Yu
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Density Functional ◽  
Molecular Crystals ◽  
Density Functional Theory Method ◽  
Theory Method ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
The Density Functional Theory

The crystal structure of 1, 3-propanediol bis (4-aminobenzoate) has been determined by single crystal X-ray diffraction. The UV-vis spectra have been characterized experimentally. The nonlinear optical properties were investigated with the density functional theory method. The calculated first hyperpolarizability values are 7.69×10-30, 14.22×10-30 and 26.66×10-30 esu for the monomer, dimmer and trimer structure of the compound. The results show that the compound has high hyperpolarizability and the hyperpolarizability multipled along with the increasing number of the molecules.

Surface-grafted lanthanoid complexes of the tungstosilicate polyanion [SiW12O40]4−: a synthetic, structural and computational investigation

2018 ◽  
Vol 74 (11) ◽  
pp. 1300-1309 ◽  
Author(s):  
Shadi Derakhshanrad ◽  
Masoud Mirzaei ◽  
Atefeh Najafi ◽  
Chris Ritchie ◽  
Antonio Bauzá ◽  
...  
Keyword(s):  
Dicarboxylic Acid ◽  
Intermolecular Interactions ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Three Dimensional ◽  
Computational Investigation ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Supramolecular Architectures

As an extension of our continued interest in the preparation of inorganic–organic hybrids, we report the successful hydrothermal synthesis of sodium tris[triaqua(μ-1,10-phenanthroline-2,9-dicarboxylato)dysprosium(III)] silicododecatungstate dodecahydrate, {[DyNa(C14H6N2O4)3(H2O)9(SiW12O40)]·12H2O}nor Na[Dy(PDA)(H2O)3]3[SiW12O40]·12H2O (1), and sodium aqua tris[tetraaqua(μ-4-hydroxypyridine-2,6-dicarboxylato)praseodymium(III)] silicododecatungstate dodecahydrate, {[NaPr(C7H3NO5)3(H2O)13(SiW12O40)]·12H2O}nor Na(H2O)[Pr(pydc-OH)(H2O)4]3[SiW12O40]·12H2O (2) (in which H2PDA is 1,10-phenanthroline-2,9-dicarboxylic acid and H2pydc-OH is 4-hydroxypyridine-2,6-dicarboxylic acid or chelidamic acid). Both compounds have been characterized using elemental analysis, IR spectroscopy and X-ray diffraction methods. Structural characterization by single-crystal X-ray diffraction reveals that these compounds consist of [SiW12O40]4−Keggin-type polyoxometalates (POMs), where a single {W3O13} triad is decorated with a trinuclear Ln complex. Moreover, the decorated polyanions are involved in a series of intermolecular interactions, such as hydrogen bonds and anion–π interactions, resulting in three-dimensional supramolecular architectures. Density functional theory (DFT) studies were conducted to support these intermolecular interactions in both1and2, and have been rationalized using molecular electrostatic potential (MEP) surface calculations.

scholarly journals Halogen Bonding in New Dichloride-Cobalt(II) Complex with Iodo Substituted Chalcone Ligands

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 354 ◽  
Author(s):  
Lukáš Masaryk ◽  
Ján Moncol ◽  
Radovan Herchel ◽  
Ivan Nemec
Keyword(s):  
Density Functional ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Noncovalent Interaction ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
The Density Functional Theory ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The synthesis and properties of new chalcone ligand 4I-L ((2E)-1-[4-(1H-imidazol-1-yl)phenyl]-3-(4-iodophenyl)prop-2-en-1-one) and tetracoordinate Co(II) complex [Co(4I-L)2Cl2], (1a), are reported in this article. Upon recrystallization of 1a, the single crystals of [Co(4I-L)4Cl2]·2DMF·3Et2O (1b) were obtained and crystal structure was determined using X-ray diffraction. The non-covalent interactions in 1b were thoroughly analyzed and special attention was dedicated to interactions formed by the peripheral iodine substituents. The density functional theory (DFT), atoms in molecule (AIM) and noncovalent interaction (NCI) methods and electronic localization function (ELF) calculations were used to investigate halogen bond formed between the iodine functional groups and co-crystallized molecules of diethyl ether.

Chemistry of transition-metal complexes containing functionalized phosphines: synthesis and structural analysis of rhodium(I) complexes containing allyl and cyanoalkylphosphines

2020 ◽  
Vol 76 (9) ◽  
pp. 932-946
Author(s):  
Reinaldo Atencio ◽  
Gustavo Chacón ◽  
Lisbeth Mendoza ◽  
Teresa González ◽  
Julia Bruno-Colmenarez ◽  
...  
Keyword(s):  
Density Functional ◽  
Three Dimensional ◽  
Coupling Constants ◽  
Molecular Surface ◽  
Planar Geometry ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Conformational Preferences ◽  
Square Planar

A series of related acetylacetonate–carbonyl–rhodium compounds substituted by functionalized phosphines has been prepared in good to excellent yields by the reaction of [Rh(acac)(CO)2] (acac is acetylacetonate) with the corresponding allyl-, cyanomethyl- or cyanoethyl-substituted phosphines. All compounds were fully characterized by 31P, 1H, 13C NMR and IR spectroscopy. The X-ray structures of (acetylacetonato-κ2 O,O′)(tert-butylphosphanedicarbonitrile-κP)carbonylrhodium(I), [Rh(C5H7O2)(CO)(C8H13N2)] or [Rh(acac)(CO)(tBuP(CH2CN)2}] (2b), (acetylacetonato-κ2 O,O′)carbonyl[3-(diphenylphosphanyl)propanenitrile-κP]rhodium(I), [Rh(C5H7O2)(C15H14N)(CO)] or [Rh(acac)(CO){Ph2P(CH2CH2CN)}] (2h), and (acetylacetonato-κ2 O,O′)carbonyl[3-(di-tert-butylphosphanyl)propanenitrile-κP]rhodium(I), [Rh(C5H7O2)(C11H22N)(CO)] or [Rh(acac)(CO){tBu2P(CH2CH2CN)}] (2i), showed a square-planar geometry around the Rh atom with a significant trans influence over the acetylacetonate moiety, evidenced by long Rh—O bond lengths as expected for poor π-acceptor phosphines. The Rh—P distances displayed an inverse linear dependence with the coupling constants J P-Rh and the IR ν(C[triple-bond]O) bands, which accounts for the Rh—P electronic bonding feature (poor π-acceptors) of these complexes. A combined study from density functional theory (DFT) calculations and an evaluation of the intramolecular H...Rh contacts from X-ray diffraction data allowed a comparison of the conformational preferences of these complexes in the solid state versus the isolated compounds in the gas phase. For 2b, 2h and 2i, an energy-framework study evidenced that the crystal structures are mainly governed by dispersive energy. In fact, strong pairwise molecular dispersive interactions are responsible for the columnar arrangement observed in these complexes. A Hirshfeld surface analysis employing three-dimensional molecular surface contours and two-dimensional fingerprint plots indicated that the structures are stabilized by H...H, C...H, H...O, H...N and H...Rh intermolecular interactions.

scholarly journals Synthesis and Physical Properties of Iridium-Based Sulfide Ca1−xIr4S6(S2) [x = 0.23–0.33]

2022 ◽  
Vol 3 (1) ◽  
pp. 41-52
Author(s):  
Michael Vogl ◽  
Martin Valldor ◽  
Roman Boy Piening ◽  
Dmitri V. Efremov ◽  
Bernd Büchner ◽  
...  
Keyword(s):  
Density Functional ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
Metallic Behavior ◽  
Functional Theory ◽  
X Ray ◽  
Lattice Constants ◽  
The Density Functional Theory ◽  
Xrd Techniques

We present the synthesis and characterization of the iridium-based sulfide Ca1−xIr4S6(S2). Quality and phase analysis were conducted by means of energy-dispersive X-ray spectroscopy (EDXS) and powder X-ray diffraction (XRD) techniques. Structure analysis reveals a monoclinic symmetry with the space group C 1 2/m 1 (No. 12), with the lattice constants a = 15.030 (3) Å, b = 3.5747 (5) Å and c = 10.4572 (18) Å. Both X-ray diffraction and EDXS suggest an off-stoichiometry of calcium, leading to the empirical composition Ca1−xIr4.0S6(S2) [x = 0.23–0.33]. Transport measurements show metallic behavior of the compound in the whole range of measured temperatures. Magnetic measurements down to 1.8 K show no long range order, and Curie–Weiss analysis yields θCW = −31.4 K, suggesting that the compound undergoes a magnetic state with short range magnetic correlations. We supplement our study with calculations of the band structure in the framework of the density functional theory.

Crystal chemistry, X-ray diffraction reference patterns, and bandgap studies for (BaxSr1–x)2CoWO6 (x = 0.1, 0.2, 0.3, 0.5, 0.7, and 0.9)

2020 ◽  
Vol 35 (3) ◽  
pp. 197-205
Author(s):  
W. Wong-Ng ◽  
G. Y. Liu ◽  
D. D. Shi ◽  
Y. Q. Yang ◽  
R. Derbeshi ◽  
...  
Keyword(s):  
Density Functional ◽  
Alkaline Earth ◽  
Double Perovskite ◽  
Density Functional Theory Calculations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Rietveld Refinements ◽  
X Ray ◽  
Diffraction Patterns ◽  
End Members

X-ray reference powder patterns and structures have been determined for a series of cobalt- and tungsten-containing cubic alkaline-earth perovskites, (BaxSr1–x)2CoWO6 (x = 0.1, 0.2, 0.3, 0.5, 0.7, and 0.9). The structure of the end members of the series, Sr2CoWO6 and Ba2CoWO6, were tetragonal and cubic, respectively, agreeing with the literature data. From Rietveld refinements, it was found that when x = 0.1 and 0.2, the structure was tetragonal I4/m (a = 5.60481(6) and 5.62305(11) Å and c = 7.97989(12) and 7.9847(2) Å, respectively; Z = 2). When x > 0.2, the structure was cubic (Fm$\bar{3}$m, No. 225; Z = 4) (from x = 0.3 to 0.9, a increases from 7.98399(13) to 8.08871(10) Å). This tetragonal series of compounds exhibit the characteristics of a distorted double-perovskite structure. The bond valence sum values for the alkaline-earth (Ba, Sr) sites in all (BaxSr1−x)2CoWO6 members are greater than the ideal value of 2.0, indicating over-bonding situation, whereas for the W sites, as x increases, a change from under-bonding to slightly over-bonding situation was observed. Density functional theory calculations revealed that while Sr2CoWO6 is a semiconductor, Ba2CoWO6 and SrBaCoWO6 are half-metals. Powder X-ray diffraction patterns of this series of compounds (BaxSr1−x)2CoWO6, with x = 0.1, 0.2, 0.3, 0.5, 0.7, and 0.9, have been submitted to be included in the Powder Diffraction File.

scholarly journals Моделирование фазовых переходов графитов в алмазоподобные фазы

2018 ◽  
Vol 60 (7) ◽  
pp. 1290
Author(s):  
Е.А. Беленков ◽  
В.А. Грешняков
Keyword(s):  
Density Functional ◽  
Local Density ◽  
X Ray Diffraction ◽  
Generalized Gradient ◽  
Functional Theory ◽  
X Ray ◽  
Graphene Layers ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory ◽  
Diffraction Patterns

AbstractThe method of the density functional theory is used to study structural transformations between graphites and diamond-like phases. The calculations have been carried out in two approximations: a local density approximation and a generalized gradient approximation. It is found that the phase transitions of hexagonal graphene layers to a cubic diamond and diamond-like phases must occur at uniaxial compressions of ~57–71 GPa, whereas some diamond-like phases can be obtained from tetragonal graphene layers at significantly lower pressures of 32–52 GPa. The X-ray diffraction patterns have been calculated for the phase transition of graphite I 4_1/ amd to tetragonal LA 10 phase that takes place at the minimum pressure that can be used for experimental identification of these compounds.

scholarly journals Experimental and theoretical study of the chalcone molecule (E)-3-(2,6-difluorophenyl)-1-(furan-2-yl)-prop-2-en-1-one

2020 ◽  
Author(s):  
Antônio S. N. Aguiar ◽  
Jaqueline E. Queiroz ◽  
Pollyana P. Firmino ◽  
Wesley F. Vaz ◽  
Ademir J. Camargo ◽  
...  
Keyword(s):  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Theoretical Study ◽  
X Ray Diffraction ◽  
Theoretical Level ◽  
Acid Base ◽  
Functional Theory ◽  
X Ray ◽  
The Density Functional Theory ◽  
Structural And Electronic Properties

In this work, we synthesized chalcone (E)-3-(2,6-difluorophenyl)-1-(furan-2-yl)-prop-2-en-1-one (DTP) via Claisen-Schmidt condensation. The supramolecular arrangement of the obtained compound was characterized by X-ray diffraction and Hirshfeld surface, and its crystalline structure was determined. The DTP molecule was studied using the Density Functional Theory, at the theoretical level M06-2X/6-311G ++G, in order to obtain information about its structural and electronic properties. A map of molecular electrostatic potential was obtained to predict the types of interactions and their acid-base behavior.

Sign in / Sign up

Export Citation Format

Share Document