Synthesis, characterization, crystal structure and density functional theory (DFT) calculations of dioxomolybdenum (VI) complexes of an ONS donor ligand derived from benzoylacetone and S-benzyl dithiocarbazate

Polyhedron ◽  
2013 ◽  
Vol 50 (1) ◽  
pp. 602-611 ◽  
Author(s):  
Manashi Chakraborty ◽  
Sathi Roychowdhury ◽  
Nikhil Ranjan Pramanik ◽  
Tapas Kumar Raychaudhuri ◽  
Tapan Kumar Mondal ◽  
...  
RSC Advances ◽  
2019 ◽  
Vol 9 (34) ◽  
pp. 19657-19661 ◽  
Author(s):  
Gwladys Steciuk ◽  
Seyedayat Ghazisaeed ◽  
Boris Kiefer ◽  
Jakub Plášil

The crystal structure of the U(iv)-phosphate mineral vyacheslavite has been solved from precession electron diffraction tomography (PEDT) data from the natural nano-crystal and further refined using density-functional theory (DFT) calculations.


2018 ◽  
Vol 33 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Joel W. Reid ◽  
James A. Kaduk ◽  
Lidia Matei

The crystal structure of MoO2(O2)H2O has been solved by analogy with the WO2(O2)H2O structure and refined with synchrotron powder diffraction data obtained from beamline 08B1-1 at the Canadian Light Source. Rietveld refinement, performed with the software package GSAS, yielded monoclinic lattice parameters of a = 12.0417(4) Å, b = 3.87003(14) Å, c = 7.38390(24) Å, and β = 78.0843(11)° (Z = 4, space group P21/n). The structure is composed of double zigzag molybdate chains running parallel to the b-axis. The Rietveld refined structure was compared with density functional theory (DFT) calculations performed with CRYSTAL14, and show strong agreement with the DFT optimized structure.


2021 ◽  
Vol 68 (3) ◽  
pp. 718-727
Author(s):  
Ibrahim Bouabdallah ◽  
Tarik Harit ◽  
Mahmoud Rahal ◽  
Fouad Malek ◽  
Monique Tillard ◽  
...  

The single crystal X-ray structure of new 1,1’-bis(2-nitrophenyl)-5,5’-diisopropyl-3,3’-bipyrazole, 1, is triclinic P I–, a = 7.7113(8), b = 12.3926(14), c = 12.9886(12) Å, α = 92.008(8), β = 102.251(8), γ = 99.655(9)°. The structural arrangement is compared to that of 5,5’-diisopropyl-3,3’-bipyrazole, 5, whose single crystal structure is found tetragonal I41/a, a = b = 11.684(1), c = 19.158(1) Å. The comparison is also extended to the structures previously determined for 1,1’-bis(2-nitrophenyl)-5,5’-propyl-3,3’-bipyrazole, 2, 1,1’-bis(4-nitrophenyl)-5,5’-diisopropyl-3,3’-bipyrazole, 3, and 1,1’-bis(benzyl)-5,5’-diisopropyl-3,3’-bipyrazole, 4. Density Functional Theory (DFT) calculations are used to investigate the molecular geometries and to determine the global reactivity parameters. The geometry of isolated molecules and the molecular arrangements in the solid state are analyzed according to the nature of the groups connected to the bipyrazole core.


2010 ◽  
Vol 163 ◽  
pp. 256-259
Author(s):  
Gabriela Bednarek ◽  
Maria Nowak ◽  
Joachim Kusz ◽  
Jerzy Ossowski

N,N’ – bis – (2– hydroxy – ethylene) – terephthalamide (BHETA) has been obtained by aminolysis of polyethylene terephthalate (PET) using excess of monoethanoloamine and it has been physicochemically characterized [1]. In this paper there are shown the results of the multi-temperature X-ray measurement which were performed to provide information about the stability of the structure. Detailed temperature analysis of the crystal structure allows us to determine properties of the compound which is very important product of recycling PET wastes in order to use it for further chemical reactions. The structure of the title compound was also modelled by density functional theory (DFT) calculations.


Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1219
Author(s):  
Olga Nikolaevna Makshakova ◽  
Daria Vladimirovna Shurtakova ◽  
Alexey Vladimirovich Vakhin ◽  
Peter Olegovich Grishin ◽  
Marat Revgerovich Gafurov

Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) doped with various transition metals has generated great interest in view of its potential application in a wide variety of fields, including in catalysis as a support with a series of attractive properties. Despite a large number of experimental works devoted to the synthesis and application of iron-substituted hydroxyapatites, problems concerning the location, introduced defects, and charge compensation schemes for Fe2+ and/or Fe3+ cations in the crystal structure of HAp remain unclear. This paper is devoted to the comprehensive analysis of iron (II) and (III) introduction into the HAp lattice by density functional theory (DFT) calculations. We show that the inclusion of Fe2+ in the Ca(1) and Ca(2) positions of HAp is energetically comparable. For the Fe3+, there is a clear preference to be included in the Ca(2) position. The inclusion of iron results in cell contraction, which is more pronounced in the case of Fe3+. In addition, Fe3+ may form a shorter linkage to oxygen atoms. The incorporation of both Fe2+ and Fe3+ leads to notable local reorganization in the HAp cell.


Nanoscale ◽  
2018 ◽  
Vol 10 (22) ◽  
pp. 10357-10364 ◽  
Author(s):  
Pu Wang ◽  
Xiangxiang Sun ◽  
Xia Liu ◽  
Lin Xiong ◽  
Zhongyun Ma ◽  
...  

A new stable structural form of Au20(SR)16 cluster is theoretically predicted. The density functional theory (DFT) calculations with the inclusion of dispersion corrections indicated the nanocrystal-like isomer (Au20-Iso1) has comparable and even lower total energies compared to the non-fcc crystal structure of Au20(SPh-tBu)16.


2021 ◽  
Vol 8 (1) ◽  
pp. 3-11
Author(s):  
Soumia Merazka ◽  
Lamia Hammoudi ◽  
Mohammed Kars ◽  
Mohamed Sidoumou ◽  
Thierry Roisnel

The Crystal structure of both α-Ti2O3 and its new substructure with a halved c-axis has been investigated by single-crystal X-ray diffraction and density functional theory (DFT) calculations. The α-Ti2O3 substructure described in the R-3m space group, reveals an unusual 12-fold high coordination of Ti atoms forming edge and face-sharing distorted hexagonal prisms TiO12 stacking along the c-axis. The Hubbard-corrections predict a close bandgap for both α-Ti2O3 and its substructure; whereas a comparative study of their relative stability indicates that the substructure is thermodynamically less stable.


2021 ◽  
Author(s):  
Xinpeng Zhao ◽  
Zhimin Zhou ◽  
hu luo ◽  
Yanfei Zhang ◽  
Wang Liu ◽  
...  

Combined experiments and density functional theory (DFT) calculations provided insights into the role of the environment-friendly γ-valerolactone (GVL) as a solvent in the hydrothermal conversion of glucose into lactic acid...


Author(s):  
Hanlin Gan ◽  
Liang Peng ◽  
Feng Long Gu

The mechanism of the Cu(i)-catalyzed domino reaction furnishing 1-aryl-1,2,3-triazole assisted by CuI and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is explored with density functional theory (DFT) calculations.


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