Atomic charge distribution in fourfold coordinated amorphous materials. Carbon and silicon

1991 ◽  
Vol 70 (4) ◽  
pp. 351-359
Author(s):  
S. Kugler ◽  
G. Náray-Szabó
Keyword(s):  
Charge Distribution ◽  
Amorphous Materials ◽  
Atomic Charge

Atomic Charge Distribution in Diamondlike Amorphous Carbon

1991 ◽  
Vol 30 (Part 2, No. 7A) ◽  
pp. L1149-L1151 ◽  
Author(s):  
Sándor Kugler ◽  
Gábor Náray-szabó
Keyword(s):  
Charge Distribution ◽  
Amorphous Carbon ◽  
Atomic Charge

scholarly journals Prediction of Reaction Intermediate(s) of Pentachlorophenol Degradation: An Application of Atomic Charge Distribution Calculations

2011 ◽  
Vol 32 (10) ◽  
pp. 3549-3550 ◽  
Author(s):  
Byung-Dae Lee ◽  
Min-Joo Lee ◽  
Shun-Hwa Lee ◽  
Chul-Hee Lee ◽  
Yeoung-Chan Kim
Keyword(s):  
Charge Distribution ◽  
Atomic Charge ◽  
Reaction Intermediate

Electronic, Vibrational, and Structural Study of Polysaccharide Agar-Agar Biopolymer

2021 ◽  
Vol 33 ◽  
pp. 35-46
Author(s):  
Ankita Pandey ◽  
Abhishek Kumar Gupta ◽  
Shivani Gupta ◽  
Sarvesh Kumar Gupta ◽  
Rajesh Kumar Yadav
Keyword(s):  
Charge Distribution ◽  
Molecular Orbital ◽  
Structural Study ◽  
Density Functional ◽  
Vibrational Analysis ◽  
Chemical Properties ◽  
Atomic Charge ◽  
Dft Method ◽  
Basis Set ◽  
Mulliken Charge

Polysaccharide biopolymer Agar-Agar extracted from red algae is a natural and biodegradable polymer. It is a combination of agarose (a neutral and linear polymer, with repeated units of agarobiose) and a heterogeneous mixture of agaropectin (a charged sulfated polymer). In this study, a comparative study of structural vibrational and electrochemical properties of agar-agar biopolymer with two different methods HF (Hartree-Fock) and DFT (Density Functional Theory) using a basis set 631+G (d, p) is performed. The comparative structural study of agar-agar biopolymer by HF and DFT method has been carried out to calculate the stability of the molecule. The thermionic properties and Mulliken charge distribution are analysed to deliver a quantitative study of partial atomic charge distribution. The overall vibrational analysis of primal modes of the biopolymer has been studied using FTIR analysis. Based on highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) composition and energies, various chemical parameters of the biopolymer have been evaluated. The Physico-chemical properties of this polysaccharide show a strong correlation with its optimized structure. Agar-agar has its application in the electrochemical, biotechnological, and pharmaceutical fields, as a stabilizer and gelling material.

Theoretical investigation of methoxide ion reaction on the 7-methyl-4,6-dinitrobenzofuroxan

2016 ◽  
Vol 94 (8) ◽  
pp. 699-703 ◽  
Author(s):  
Mohamed Ali Boughdiri ◽  
Taoufik Boubaker ◽  
Bahoueddine Tangour
Keyword(s):  
Activation Energy ◽  
Kinetic Parameters ◽  
Charge Distribution ◽  
Theoretical Investigation ◽  
Activation Barrier ◽  
Simultaneous Detection ◽  
Atomic Charge ◽  
Water As Solvent ◽  
Fukui Indices ◽  
Methoxide Ion

Reaction of the methoxide ion on the 7-methyl-4,6-dinitrobenzofuroxan (DNBF) 1 has been studied theoretically by means of DFT/B3LYP technique to interpret the kinetic–thermodynamic competition between the three possible compounds that are carbanion DNBF− 4 and the two complexed forms (2, 3) of the methoxide group in positions 5 and 7, respectively. Optimized geometry, nbo atomic charge distribution, thermodynamic/kinetic parameters (ΔrH°T, ΔrS°T, ΔrG°T, ΔH*, ΔS*, and ΔG*) and IRC path have been calculated for possible products and their transitional states using water as solvent. All obtained ΔrG°T are negative, ranging from −19.16 to −42.87 kcal mol−1 (1 cal = 4.184 J), indicating the possible observation of all products, but the experimenters only detected the anionic form DNBF−. Fukui indices, which were calculated by means of NBO atomic charge distribution, confirm the electrophilicity of the sites C5 and C7. Transition states barriers, ΔG*, are 14.97, 15.16, and 21.94 kcal mol−1 for the three possible products 2, 3, and 4, respectively, in water. As expected, the most stable compound is carbanion, but it also exhibits the highest activation barrier. If this situation formally engenders a double kinetic–thermodynamic competition, the very weak activation energy of the two complexes in C5 and C7 makes improbable the simultaneous detection of the three expected compounds.

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