scholarly journals Effect of nano metal oxides on heme molecule: molecular and biomolecular approaches

2019 ◽  
Vol 10 (1) ◽  
pp. 4837-4845
Keyword(s):  
Gas Phase ◽  
Complex Structure ◽  
Geometry Optimization ◽  
Complex Form ◽  
High Reactivity ◽  
Quantum Mechanical ◽  
Interacting Species ◽  
Heme Structure ◽  
Main Component ◽  
Heme Molecule

Interaction of components of living cells with various nanomaterials in the gas phase has been one of extensive concern since they become intensively utilized in various life aspects. This work is carried out to investigate the interaction between heme molecule, as the main component of hemoglobin, with several familiar and non-familiar divalent structures such as O2, CO2, CO, MgO, CoO, NiO, CuO and ZnO. Geometry optimization processes as well as QSAR descriptors are conducted using semiemprical quantum mechanical calculations at PM6 level. Results illustrate that adsorbing O2 and CO on heme lowers their TDM helping heme in performing its transportation function and not interacting with other species. On the other hand, when CoO and ZnO interacting with heme the TDM of the resultant structures increase greatly reflecting high reactivity which may interact with other species more than performing its function. Therefore, interacting species other than O2 may disturb the transportation function of heme structure. QSAR data of IP regarding interaction of O2 with heme ensure the TDM result that reflects lowering its activity. IP of H-CO adsorbed is the lowest indicating high reactivity while those of H-O2, H-CO2, H-MgO and H-NiO in the complex form are the highest values indicating that it is difficult to form a complex structure with them. Therefore, heme interactions with structures rather than O2 and CO2 affects negatively its function as gas transporter.

Predicting the Shelf-Life of Single Base Propellants

2014 ◽  
Vol 631-632 ◽  
pp. 1257-1262
Author(s):  
Myoung Jin Choi ◽  
Hyung Ju Park ◽  
Jaek Yung Yang
Keyword(s):  
Data Mining ◽  
Shelf Life ◽  
Decomposition Product ◽  
Reduction Rate ◽  
Storage Period ◽  
High Reactivity ◽  
Single Base ◽  
Using Data ◽  
Main Component ◽  
Acid Esters

Ammunitions stored in war fields have lifespans that are related to the single base propellants, as Nitrocellulose (NC), the main component of propelling gunpowder, decomposes naturally into an unstable substance, similar to other nitric acid esters. Decomposition is inevitable; however a decomposition product (NO2, NO3, and HNO3) and tranquillizer DPA (Diphenylamine), which have high reactivity, can be added to a propellant to restrain the induction of automatic catalysis by a decomposition product. The decay rate of the tranquillizer is also affected by the production rate of the decomposition product of NC. Thus, as the storage period of single base propellants lengthens, the reduction rate of the tranquillizer content increases. This paper presents a new methodology based on data mining and regression analysis for estimating the shelf-life of single base propellants using data from the ASRP to 105mm HE (KM1 and M1).

Molecular orbital structures of sulfones

1982 ◽  
Vol 60 (6) ◽  
pp. 730-734 ◽  
Author(s):  
Russell J. Boyd ◽  
Jeffrey P. Szabo
Keyword(s):  
Crystal Structure ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Geometry Optimization ◽  
Membered Ring ◽  
Molecular Orbital Calculations ◽  
Bond Lengths ◽  
Comparison With Experiment ◽  
The Difference

Abinitio molecular orbital calculations are reported for several cyclic and acyclic sulfones. The geometries of XSO2Y, where X, Y = H, F, or CH3 are optimized at the STO-3G* level. Similar calculations are reported for the smallest cyclic sulfone, thiirane-1,1 -dioxide, as well as the corresponding sulfoxide, thiirane-1-oxide, and the parent sulfide, thiirane. Where comparison with experiment is possible, the agreement is satisfactory. In order to consider the possibility of substantial differences between axial and equatorial S—O bonds in the gas phase, as observed in the crystal structure of 5H,8H-dibenzo[d,f][1,2]-dithiocin-1,1-dioxide, STO-3G* calculations are reported for a six-membered ring, thiane-1,1-dioxide, and a model eight-membered ring. Limited geometry optimization of the axial and equatorial S—O bonds in the chair conformations of the six- and eight-membered rings leads to bond lengths of 1.46 Å with the difference being less than 0.01 Å.

Processing of natural and casing-head gases by the gas-phase oxidation

2021 ◽  
Vol 21 (4) ◽  
pp. 227-237
Author(s):  
V. S. Arutyunov ◽  
V. I. Savchenko ◽  
I. V. Sedov ◽  
A. V. Nikitin
Keyword(s):  
Natural Gas ◽  
Gas Phase ◽  
World Economy ◽  
Direct Methods ◽  
Hydrocarbon Gases ◽  
The World ◽  
Phase Oxidation ◽  
Gas Phase Oxidation ◽  
Chemical Products ◽  
Main Component

The paper considers the growing importance of gas chemistry for the world economy and the related necessity of developing new, particularly noncatalytic technologies for the conversion of natural gas and other hydrocarbon gases into chemical products. The available and promising noncatalytic processes of their conversion into syngas as well as the direct methods for the synthesis of chemical products from methane, which is the main component of natural gas, are discussed.

Workshop on „the Applications of Quantum Mechanical Methods in Gas Phase Ion Chemistry“

1999 ◽  
pp. 431-444
Author(s):  
J. HruŠák ◽  
J. F. Liebman ◽  
P. P. Gaspar ◽  
D. J. Berger ◽  
E. Leere Oiestad ◽  
...  
Keyword(s):  
Gas Phase ◽  
Quantum Mechanical ◽  
Ion Chemistry ◽  
Gas Phase Ion Chemistry ◽  
Mechanical Methods ◽  
Gas Phase Ion

scholarly journals Synthesis, Characterization, Catalytic Activity, and DFT Calculations of Zn(II) Hydrazone Complexes

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4043 ◽  
Author(s):  
Temiloluwa T. Adejumo ◽  
Nikolaos V. Tzouras ◽  
Leandros P. Zorba ◽  
Dušanka Radanović ◽  
Andrej Pevec ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Density Functional ◽  
Chemical Potential ◽  
Chemical Reactivity ◽  
Geometry Optimization ◽  
Coupling Reaction ◽  
Functional Theory ◽  
Reactivity Descriptors

Two new Zn(II) complexes with tridentate hydrazone-based ligands (condensation products of 2-acetylthiazole) were synthesized and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy and single crystal X-ray diffraction methods. The complexes 1, 2 and recently synthesized [ZnL3(NCS)2] (L3 = (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium) complex 3 were tested as potential catalysts for the ketone-amine-alkyne (KA2) coupling reaction. The gas-phase geometry optimization of newly synthesized and characterized Zn(II) complexes has been computed at the density functional theory (DFT)/B3LYP/6–31G level of theory, while the highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO and LUMO) energies were calculated within the time-dependent density functional theory (TD-DFT) at B3LYP/6-31G and B3LYP/6-311G(d,p) levels of theory. From the energies of frontier molecular orbitals (HOMO–LUMO), the reactivity descriptors, such as chemical potential (μ), hardness (η), softness (S), electronegativity (χ) and electrophilicity index (ω) have been calculated. The energetic behavior of the investigated compounds (1 and 2) has been examined in gas phase and solvent media using the polarizable continuum model. For comparison reasons, the same calculations have been performed for recently synthesized [ZnL3(NCS)2] complex 3. DFT results show that compound 1 has the smaller frontier orbital gap so, it is more polarizable and is associated with a higher chemical reactivity, low kinetic stability and is termed as soft molecule.

Quantum mechanical approach to isoleucine+OH gas phase reaction. Mechanism and kinetics

2004 ◽  
Vol 676 (1-3) ◽  
pp. 97-103 ◽  
Author(s):  
Annia Galano ◽  
J.Raúl Alvarez-Idaboy ◽  
Esther Agacino-Valdés ◽  
Ma.Esther Ruiz-Santoyo
Keyword(s):  
Reaction Mechanism ◽  
Gas Phase ◽  
Quantum Mechanical ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
Mechanical Approach ◽  
Mechanism And Kinetics ◽  
Quantum Mechanical Approach
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