The FT-IR and FT-Raman vibrational spectra of selegiline were recorded. The optimized geometry and wavenumbers in the ground state were calculated using density functional (B3LYP) method with standard 6-31G(d,p) basis set. The computed B3LYP/6-31G(d,p) results show the best agreement with the experimental values over the other methods. Natural bond orbital analysis of selegiline is also carried...

Theoretical studies on anthracene and a series of its derivatives were performed using the AM1 method and DFT. Based on B3LYP/6-31G(d) optimized geometries, the electronic, IR and NMR spectra of anthracene oligomers were calculated using the Indo/Cis, AM1 and B3LYP/6-31G(d) methods, respectively. The energy gaps of the oligomers decreased and the main absorptions in the electronic spectra of th...

35Cl NMR spectra were measured using the highest-temperature solid phase of n-CxH(2x+1) NH3Cl and n-CxH(2x+1)ND3Cl (x= 5−10). The observed quadrupole coupling constants (e2Qqh−1) decreased upon heating in this phase, and significant frequency differences of ca. 20 – 30 kHz were detected between the -NH3 and -ND3 analogs. In the low-temperature range of this phase, the observed e2Qqh−1 values fo...

The mechanism of the enantioselective deprotonation of cyclohexene oxide with isopinocampheyl-based chiral lithium amide was studied by quantum chemical calculations. The transition states of eight molecules were fully optimized at the ab initio HF/3-21G and density functional B3LYP/3-21G levels with Gaussian 98. The activation energies were calculated at the B3LYP/6-31+G(3df,2p)//B3LYP/3-21G l...

Geometric parameters and FT-IR spectrum of 6-bromo-8-thia-1,4epoxybicyclo[4.3.0]non-2-ene were computed by the HF, B3LYP, B3PW91 and mPW1PW91 methods in conjunction with the 6-31G(d,p) basis set. The calculated IR spectra are in a good agreement with the observed FT-IR spectrum. A general better performance of B3LYP, B3PW91 and mPW1PW91 versus HF was quantitatively characterized by using PAVF 1...

In this research, geometrical structures of armchair single walled boron nitride nanotube (SWBNNT) and armchair single walled aluminum nitride nanotube (SWAlNNT) were optimized by Density Functional Theory (DFT) in the gas phase, both having the same length of 5 angstrom and n=9, m=9. B3LYP/6-31G* level of theory have been used to determine and compare electronic properties, n...

In this study the hardness SWCT was calculated with B3LYP,HF method and 3-21G,6-31G,6-311G basis set .Then it was investigated with the best method(B3LYP) and basis set(6-31G) to study the adsorption effects CO2 on the hardness of SWCNT with gap HOMO-LUMO in two shape: Horizontal, Vertical and Top-Center-Bridge and We also provide the effects of CO2 adsorption on the elect...

In this research, geometrical structures of armchair single walled boron nitride nanotube (SWBNNT) and armchair single walled aluminum nitride nanotube (SWAlNNT) were optimized by Density Functional Theory (DFT) in the gas phase, both having the same length of 5 angstrom and n=9, m=9. B3LYP/6-31G* level of theory have been used to determine and compare electronic properties, n...

In this study, a combined quantum mechanical and experimental analyses were performed to investigate crystal structure of the immediate degradation product of TNT, 2-hydroxylamino-4,6-dinitrotoluene (2HADNT) and to reveal its important chemical properties. Leakage of 2-HADNT has caused serious environmental pollution and therefore raises widespread concerns. In the quantum mechanical analysis, ...

Density-functional theory ~DFT! calculations of indirect nuclear magnetic resonance spin–spin coupling tensors J, with the anisotropic but symmetric parts being the particular concern, are carried out for a series of molecules with the linear response ~LR! method. For the first time, the anisotropic components of J are reported for a hybrid functional. Spin–spin tensors calculated using the loc...