scholarly journals Quantum chemical modeling of orthophosphoric acid adsorption sites on hydrated anatase surface

Surface ◽  
2020 ◽  
Vol 12(27) ◽  
pp. 20-35
Author(s):  
О. V. Filonenko ◽  
◽  
E. M. Demianenko ◽  
V. V. Lobanov ◽  
◽  
...  
Keyword(s):  
Water Molecule ◽  
Quantum Chemical ◽  
Formation Energy ◽  
Orthophosphoric Acid ◽  
Basis Set ◽  
Quantum Chemical Modeling ◽  
Energy Effect ◽  
Chemical Modeling ◽  
Adsorption Sites ◽  
Thermodynamic Probability

Quantum chemical modeling of orthophosphoric acid adsorption sites on the hydrated surface of anatase was performed by the method of density functional theory (exchange-correlation functional PBE0, basis set 6-31 G(d,p)). The influence of the aqueous medium was taken into account within the framework of the continual solvent model. The work uses a cluster approach. The anatase surface is simulated by a neutral Ti(OH)4(H2O)2 cluster. The results of analysis of the geometry and energy characteristics of all the calculated complexes show that the highest interaction energy is inherent to the intermolecular complex of orthophosphoric acid and hydrated surface of anatase, where the oxygen atom of the phosphoryl group (О=Р≡) forms a hydrogen bond with a hydrogen atom of the coordinated water molecule of Ti(OH)4(H2O)2 cluster and two hydrogen atoms of the hydroxyl groups of the orthophosphoric acid molecule form two hydrogen bonds with two oxygen atoms of the titanol groups. The formation energy effect of this complex is -134.0 kJ/mol. The formation energy effect of the complex with separated charges by the proton transfer from the molecule H3PO4 to the Ti(OH)4(H2O)2 cluster with the formation of dihydrogen phosphate anion and the protonated form of the titanol group (º) is -131.1 kJ/mol, so indicating less thermodynamic probability of such intermolecular interaction. The smallest thermodynamic probability (-123.9 kJ/mol) of complexation between orthophosphoric acid and hydrated anatase surface where a water molecule moves from the coordination sphere of the titanium atom. The calculation results indicate a possible adsorption of the H3PO4 molecule in an aqueous solution on the hydrated anatase surface. Taking into account the effect of the solvent within the polarization continuum insignificantly changes the adsorption energy, which is -44.5 kJ/mol; for vacuum conditions this value is -49.0 kJ/mol.

Non-nuclear attractors on Si–Si bond in quantum-chemical modeling as basis set inadequacy

2003 ◽  
Vol 288 (2-3) ◽  
pp. 159-169 ◽  
Author(s):  
O.A Zhikol ◽  
A.F Oshkalo ◽  
O.V Shishkin ◽  
O.V Prezhdo
Keyword(s):  
Quantum Chemical ◽  
Basis Set ◽  
Quantum Chemical Modeling ◽  
Chemical Modeling

scholarly journals Quantum Chemical Studies and Electrochemical Investigations of Polymerized Brilliant Blue-Modified Carbon Paste Electrode for In Vitro Sensing of Pharmaceutical Samples

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 135
Author(s):  
Pattan-Siddappa Ganesh ◽  
Sang-Youn Kim ◽  
Savas Kaya ◽  
Rajae Salim ◽  
Ganesh Shimoga ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Carbon Paste Electrode ◽  
Quantum Chemical ◽  
Electrochemical Sensing ◽  
Quantum Chemical Modeling ◽  
Brilliant Blue ◽  
Carbon Paste ◽  
Chemical Modeling ◽  
The Real ◽  
Paste Electrode

To develop an electrochemical sensor for electroactive molecules, the choice and prediction of redox reactive sites of the modifier play a critical role in establishing the sensing mediating mechanism. Therefore, to understand the mediating mechanism of the modifier, we used advanced density functional theory (DFT)-based quantum chemical modeling. A carbon paste electrode (CPE) was modified with electropolymerization of brilliant blue, later employed for the detection of paracetamol (PA) and folic acid (FA). PA is an analgesic, anti-inflammatory and antipyretic prescription commonly used in medical fields, and overdose or prolonged use may harm the liver and kidney. The deficiency of FA associated with neural tube defects (NTDs) and therefore the quantification of FA are very essential to prevent the problems associated with congenital deformities of the spinal column, skull and brain of the fetus in pregnant women. Hence, an electrochemical sensor based on a polymerized brilliant blue-modified carbon paste working electrode (BRB/CPE) was fabricated for the quantification of PA and FA in physiological pH. The real analytical applicability of the proposed sensor was judged by employing it in analysis of a pharmaceutical sample, and good recovery results were obtained. The potential excipients do not have a significant contribution to the electro-oxidation of PA at BRB/CPE, which makes it a promising electrochemical sensing platform. The real analytical applicability of the proposed method is valid for pharmaceutical analysis in the presence of possible excipients. The prediction of redox reactive sites of the modifier by advanced quantum chemical modeling-based DFT may lay a new foundation for researchers to establish the modifier–analyte interaction mechanisms.

Quantum chemical modeling of superbase-catalyzed reactions of acetophenone and methyl mesityl ketone with acetylene

2017 ◽  
Vol 66 (12) ◽  
pp. 2227-2233 ◽  
Author(s):  
V. B. Kobychev ◽  
V. B. Orel ◽  
D. V. Zankov ◽  
N. M. Vitkovskaya ◽  
B. A. Trofimov
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Modeling ◽  
Chemical Modeling ◽  
Catalyzed Reactions

Quantum Chemical Modeling and Preparation of a Biomimetic Photochemical Switch

2007 ◽  
Vol 119 (3) ◽  
pp. 418-424 ◽  
Author(s):  
Flavio Lumento ◽  
Vinicio Zanirato ◽  
Stefania Fusi ◽  
Elena Busi ◽  
Loredana Latterini ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Modeling ◽  
Chemical Modeling
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