Spectroscopic speciation of aqueous Am(iii)–oxalate complexes

2019 ◽  
Vol 48 (27) ◽  
pp. 10023-10032 ◽  
Author(s):  
H.-K. Kim ◽  
K. Jeong ◽  
H.-R. Cho ◽  
E. C. Jung ◽  
K. Kwak ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Thermodynamic Stability ◽  
Structural Information ◽  
Oxalate Complexes

Speciation, thermodynamic stability, and structural information of aqueous oxalato-Am(iii) complexes were resolved by combinatorial use of UV-Vis-LWCC, TRLFS, and DFT calculations.

Density functional theory calculations of atomic, electronic and thermodynamic properties of cubic LaCoO3and La1−xSrxCoO3surfaces

RSC Advances ◽  
2015 ◽  
Vol 5 (1) ◽  
pp. 760-769 ◽  
Author(s):  
Shuguang Zhang ◽  
Ning Han ◽  
Xiaoyao Tan
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Properties ◽  
Dft Calculations ◽  
Phase Diagrams ◽  
Thermodynamic Stability ◽  
Electronic Structures ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Spin Polarized

Spin-polarized DFT calculations were used to investigate the atomic, electronic structures of LaCoO3and La1−xSrxCoO3surfaces. The thermodynamic stability of these surfaces was analyzed with phase diagrams. Influence of Sr-doping was also examined.

Thermodynamic stability and structure of cuprous chloride surfaces: a DFT investigation

2015 ◽  
Vol 17 (10) ◽  
pp. 7038-7045 ◽  
Author(s):  
Ibrahim A. Suleiman ◽  
Marian W. Radny ◽  
Michael J. Gladys ◽  
Phillip V. Smith ◽  
John C. Mackie ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Thermodynamic Stability ◽  
Cuprous Chloride ◽  
The Ideal

Using DFT calculations, we report the geometries and energetics of the ideal and defective low index CuCl surfaces, and show that CuCl nanoparticles have a prismatic shape in a Cl-rich environment.

The coordination of amidoxime ligands with uranyl in the gas phase: a mass spectrometry and DFT study

2016 ◽  
Vol 45 (41) ◽  
pp. 16413-16421 ◽  
Author(s):  
Zhen Qin ◽  
Siwei Shi ◽  
Chuting Yang ◽  
Jun Wen ◽  
Jianping Jia ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Dft Calculations ◽  
Gas Phase ◽  
Structural Information ◽  
Dft Study

The coordination of three amidoxime ligands (NAO, GIO, and GDO) with uranyl was compared by MS studies and DFT calculations in the gas phase to reveal the structural information.

Tuning the thermodynamic stability of oxothiomolybdenum wheels: crystal structures, studies in solution and DFT calculations

2008 ◽  
pp. 4565 ◽  
Author(s):  
Jean-François Lemonnier ◽  
Ali Kachmar ◽  
Sébastien Floquet ◽  
Jérôme Marrot ◽  
Marie-Madeleine Rohmer ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Crystal Structures ◽  
Thermodynamic Stability

Synthesis, crystal structures, magnetic properties and DFT calculations of nitrate and oxalate complexes with 3,5 dimethyl-1-(2′-pyridyl)-pyrazole-Cu(ii)

RSC Advances ◽  
2015 ◽  
Vol 5 (56) ◽  
pp. 45082-45091 ◽  
Author(s):  
Pampi Pal ◽  
Saugata Konar ◽  
Mohamed Salah El Fallah ◽  
Kinsuk Das ◽  
Antonio Bauzá ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Dft Calculations ◽  
Crystal Structures ◽  
Oxalate Complexes

Newly synthesized uncommon oxalate bridged Cu(ii) chain of formula [Cu(L)(Ox)2(H2O)]n (2) and a mononuclear Cu(ii) complex [Cu(L)(NO3)2] (1) with uncommon π hole interactions are reported and rationalized using DFT calculations.

scholarly journals Theoretical study of the mechanism of chromogenic chemodosimeters in the detection of sulfhydryl (SH–) and hydroxyl (OH–) anions

2020 ◽  
Author(s):  
Adrielly Alves ◽  
Régis Casimiro Leal
Keyword(s):  
Dft Calculations ◽  
Gas Phase ◽  
Thermodynamic Stability ◽  
Respiratory Diseases ◽  
Theoretical Study ◽  
Para Position ◽  
Aryl Group ◽  
Chronic Respiratory Diseases ◽  
The Family ◽  
Mucous Membranes

Sulfide (S2−) is a biologically and environmentally important anion. Exposure to the sulfide anion can cause chronic, respiratory diseases and irritations in the skin and mucous membranes. The protonated HS− or H2S forms are more toxic than the S2− itself. A derivative of the family of 2,4,6-triaryl-pyrylium cations bearing an amine in the para position of the 4-aryl group is sensitive for detecting sulfide anions in solution. Through DFT calculations, performed at level B3LYP/6-31+G(d) in gas phase, these authors present the thermodynamic stability of the interaction of chemodosimeters derived from the pyrilium and thiopirilium cation with hydroxyl (OH–) and sulfhydryl (SH–) anions.

scholarly journals Thermodynamic stability of mercury(II) complexes formed with environmentally relevant low-molecular-mass thiols studied by competing ligand exchange and density functional theory

2017 ◽  
Vol 14 (4) ◽  
pp. 243 ◽  
Author(s):  
Van Liem-Nguyen ◽  
Ulf Skyllberg ◽  
Kwangho Nam ◽  
Erik Björn
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Molecular Mass ◽  
Thermodynamic Stability ◽  
Ligand Exchange ◽  
Density Functional ◽  
Chemical Speciation ◽  
Functional Theory ◽  
Thiol Ligands

Environmental contextThe chemical speciation of mercury (Hg) largely controls its biogeochemical cycling and exposure to biota. Here, we investigate the thermodynamic stabilities of complexes formed between inorganic divalent Hg (HgII) and 15 biogeochemically relevant low-molecular-mass (LMM) thiol ligands. This information is critical for accurate modelling of the chemical speciation of HgII and to clarify the role of HgII–LMM thiol complexes in the cycling of Hg in the environment. AbstractInorganic divalent mercury (HgII) has a very high affinity for reduced sulfur functional groups. Reports from laboratory experiments suggest that HgII complexes with specific low-molecular-mass (LMM) thiol (RSH) ligands control rates of HgII transformation reactions. Because of methodological limitations for precise determination of the highly stable HgII complexes with LMM thiol ligands, constants reported in the literature remain inconsistent. This uncertainty impedes accurate modelling of the chemical speciation of HgII and the possibility to elucidate the role of HgII complexes with LMM thiols for Hg transformation reactions. Here, we report values of thermodynamic stability constants for 15 monodentate, two-coordinated HgII complexes, Hg(SR)2, formed with biogeochemically relevant LMM thiol ligands. The constants were determined by a two-step ligand-exchange procedure where the specific Hg(SR)2 complexes were quantified by liquid chromatography–inductively coupled plasma mass spectrometry. Thermodynamic stability constants (log β2) determined for the Hg(SR)2 complexes ranged from 34.6, N-cysteinylglycine, to 42.1, 3-mercaptopropionic acid, for the general reaction Hg2++2RS– ⇌ Hg(SR)2. Density functional theory (DFT) calculations showed that electron-donating carboxyl and carbonyl groups have a stabilising effect on the HgII–LMM thiol complexes, whereas electron-withdrawing protonated primary amino groups have a destabilising effect. Experimental results and DFT calculations demonstrated that the presence of such functional groups in the vicinity of the RSH group caused significant differences in the stability of Hg(SR)2 complexes. These differences are expected to be important for the chemical speciation of HgII and its transformation reactions in environments where a multitude of LMM thiol compounds are present.

Measurement and Reduction of Radiation Damage in Frozen Hydrated Crystalline Specimens

1978 ◽  
Vol 36 (3) ◽  
pp. 70-77 ◽  
Author(s):  
R.M. Glaeser ◽  
S.B. Hayward
Keyword(s):  
Diffraction Pattern ◽  
Structural Information ◽  
Structural Disorder ◽  
Structural Features ◽  
Biological Macromolecules ◽  
Diffraction Intensity ◽  
Object Structure ◽  
Specimen Material ◽  
Unit Cells ◽  
Identical Unit

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.

Direct visualization of phase-separated domains in lipid membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 290-291
Author(s):  
S. W. Hui ◽  
T. P. Stewart
Keyword(s):  
Lipid Membranes ◽  
Structural Information ◽  
Freeze Fracture ◽  
Biological Molecules ◽  
Vacuum Drying ◽  
Direct Visualization ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Hydrocarbon Chains

Direct electron microscopic study of biological molecules has been hampered by such factors as radiation damage, lack of contrast and vacuum drying. In certain cases, however, the difficulties may be overcome by using redundent structural information from repeating units and by various specimen preservation methods. With bilayers of phospholipids in which both the solid and fluid phases co-exist, the ordering of the hydrocarbon chains may be utilized to form diffraction contrast images. Domains of different molecular packings may be recgnizable by placing properly chosen filters in the diffraction plane. These domains would correspond to those observed by freeze fracture, if certain distinctive undulating patterns are associated with certain molecular packing, as suggested by X-ray diffraction studies. By using an environmental stage, we were able to directly observe these domains in bilayers of mixed phospholipids at various temperatures at which their phases change from misible to inmissible states.

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