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Doping reaction of some nanotubes with aluminium atom: A thermodynamic PM6 and ONIOM investigation
, Article Oriental Journal of Chemistry ; Volume 33, Issue 1 , 2017 , Pages 329-334 ; 0970020X (ISSN) ; Gholami, M. R ; Boshra, A ; Sharif University of Technology
Oriental Scientific Publishing Company
2017
Abstract
The doping reaction of boron nitride and carbon nanotubes with aluminium atom was theoretically investigated. ONIOM method and PM6 method have been used to evaluate the thermochemistry of doping reactions of single walled boron nitride nanotubes and carbon nanotubes. The enthalpy changes, Gibbs free energy changes, of studied doping reactions were evaluated at different temperatures. All nanotubes were single-walled and finite length with hydrogen saturation in the terminal atoms. The thermodynamic calculations based on the ONIOM and PM6 levels results showed (8,0)CNT is the best candidate for Al-doping reaction.result suggest the aluminum doped boron nitride nanotubes and carbon nanotubes...
Structure and conformation of α-, β- and γ-cyclodextrin in solution: theoretical approaches and experimental validation
, Article Carbohydrate Polymers ; Volume 78, Issue 1 , 2009 , Pages 10-15 ; 01448617 (ISSN) ; Ghiasi, M ; Sharif University of Technology
2009
Abstract
The anomeric carbon chemical shifts of α-, β- and γ-cyclodextrin in solution were studied experimentally and theoretically by NMR and two-layer ONIOM2 (B3LYP/6-31G*-GIAO: HF/6-31G*-GIAO) variant. The dependence between the anomeric carbon chemical shift and the glycosidic bond φ and ψ dihedral angles in d-Glcp-d-Glcp disaccharides with and (1 → 4) linkages in α-configurations were computed by Gauge-Including Atomic Orbital (GIAO) ab initio and ONIOM in water solvent using PCM methods. Complete chemical shift surfaces versus φ and ψ for this disaccharide were computed. We also present empirical formulas of the form 13C δ = f(φ, ψ) obtained by fitting the ab initio data to trigonometric series...
Prediction of Gas Phase NMR Chemical Shifts Using Gas Phase NMR and Quantum Calculations in Optimally Selected Level of Theory by Factorial Design
, Ph.D. Dissertation Sharif University of Technology ; Tafazzoli, Mohsen (Supervisor) ; Jalali Heravi, Mehdi (Supervisor)
Abstract
The optimum wave functions and calculation method were obtained using a 24 factorial design. Based on preliminary experiences, the following four factors at two level was selected: electron correlation, triple-ξ valence shell, diffuse function and polarization function.
The wave functions for calculating gas phase 1H chemical shifts of primary and secondary alcohols were optimized using factorial design as multivariate technique. Gas-phase experimental 1H chemical shifts of 18 alcohols were used to establish the best levels of theory for obtaining 1H chemical shift, among them the new experimental values of 1H chemical shifts of 10 alcohols were obtained in our laboratory. HF/6-31G(d,p)...
The wave functions for calculating gas phase 1H chemical shifts of primary and secondary alcohols were optimized using factorial design as multivariate technique. Gas-phase experimental 1H chemical shifts of 18 alcohols were used to establish the best levels of theory for obtaining 1H chemical shift, among them the new experimental values of 1H chemical shifts of 10 alcohols were obtained in our laboratory. HF/6-31G(d,p)...