scholarly journals SPECTRAL CHARACTERISTICS OF CONFORMATION ISOMERS OF MESO-OCTAMETHYL-CALIX(4)PYRROLE BASED ON QUANTUM-CHEMICAL CALCULATIONS

2018 ◽  
Vol 59 (5) ◽  
pp. 30
Author(s):  
Oleg V. Surov ◽  
Mikhail A. Krestianinov ◽  
Nugzar Zh. Mamardashvili
Keyword(s):  
Density Functional Theory ◽  
Electronic Absorption ◽  
Quantum Chemical ◽  
Density Functional ◽  
Dynamic Equilibrium ◽  
Electronic Absorption Spectra ◽  
Spectral Characteristics ◽  
Structure Optimization ◽  
Basis Set ◽  
Functional Theory

The structure optimization and calculation of electronic absorption spectra of meso-octa-methylcalix(4)pyrrole conformers was performed  by density- functional theory using hybrid B3LYP functional in cc-pVTZ basis set of Gaussian 09 package. Analysis of experimental UV-Vis spectra of solutions of calix(4)pyrrole was carried out in various solvents. The conclusion on the existence of a dynamic equilibrium between conformers in solutions of meso-octamethylcalix(4)pyrrole was made.

scholarly journals Structural and spectroscopic characterization and DFT studies of 2-amino-1,10-phenanthrolin-1-ium chloride

2019 ◽  
Vol 10 (2) ◽  
pp. 95-101
Author(s):  
Sebile Işık Büyükekşi ◽  
Namık Özdemir ◽  
Abdurrahman Şengül
Keyword(s):  
Density Functional Theory ◽  
Electronic Absorption ◽  
13C Nmr ◽  
Density Functional ◽  
Electronic Absorption Spectra ◽  
Chemical Shifts ◽  
Atomic Orbital ◽  
Basis Set ◽  
Functional Theory ◽  
1H And 13C Nmr

A versatile synthetic building block, 2-amino-1,10-phenanthrolin-1-ium chloride (L∙HCl) was synthesized and characterized by IR, 1H and 13C NMR DEPT analysis, UV/Vis and single-crystal X-ray diffraction technique. The molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO), 1H and 13C NMR chemical shifts values of the title compound in the ground state were obtained by using density functional theory (DFT/B3LYP) method with 6-311++G(d,p) basis set and compared with the experimental data. Electronic absorption spectrum of the salt was determined using the time-dependent density functional theory (TD-DFT) method at the same level. In the NMR and electronic absorption spectra calculations, the effect of solvent on the theoretical parameters was included using the default model with DMSO as solvent. The obtained theoretical parameters agree well with the experimental findings.

scholarly journals Quantum chemical studies on the molecular structure, spectroscopic and electronic properties of (6-Methoxy-2-oxo-2H-chromen-4-yl)-methyl pyrrolidine-1-carbodithioate

2016 ◽  
Vol 34 (4) ◽  
pp. 886-904 ◽  
Author(s):  
Meryem Evecen ◽  
Hasan Tanak
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electronic Absorption Spectra ◽  
Chemical Shifts ◽  
Density Functional Theory Calculations ◽  
Molecular Geometry ◽  
Basis Set ◽  
Functional Theory ◽  
Hartree Fock ◽  
Chemical Studies

AbstractIn this paper, the molecular geometry, vibrational frequencies and chemical shifts of (6-Methoxy-2-oxo-2H-chromen-4-yl)methyl pyrrolidine-1-carbodithioate in the ground state have been calculated using the Hartree-Fock and density functional methods with the 6-311++G(d,p) basis set. To investigate the nonlinear optical properties of the title compound, the polarizability and the first hyperpolarizability were calculated. The conformational properties of the molecule have been determined by analyzing molecular energy properties. Using the time dependent density functional theory, electronic absorption spectra have been calculated. Frontier molecular orbitals, natural bond orbitals, natural atomic charges and thermodynamical parameters were also investigated by using the density functional theory calculations.

scholarly journals Density functional theory study of molecular structure, Electronic properties, UV–Vis spectra on coumarin102.

2016 ◽  
Vol 13 (2) ◽  
pp. 143-152
Author(s):  
Baghdad Science Journal
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Chemical Potential ◽  
Energy Gap ◽  
Spectral Characteristics ◽  
Functional Model ◽  
Electronic States ◽  
Basis Set ◽  
Uv Spectrum ◽  
Functional Theory

The various properties of the ground and excited electronic states of coumarins 102 using density functional theory (DFT) and time-dependent density functional theory (TDDFT) was calculated by the B3LYP density functional model with 6-31G(d,p) basis set by Gaussian 09 W program. Spectral characteristics of coumarin102 have been probed into by methods of experimental UV-visible, and quantum chemistry. The UV spectrum was measured in methanol. The optimized structures, total energies, electronic states (HOMO- LUMO), energy gap, ionization potentials, electron affinities, chemical potential, global hardness, softness, global electrophilictity, and dipole moment were measured. We find good agreement between experimental data of UV spectrum and TDDFT excitationenergies.

scholarly journals Interaction of FOX-7 and Melatonin - A DFT Treatment

2019 ◽  
pp. 19-35
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemical ◽  
Composite Structures ◽  
Spectral Properties ◽  
Density Functional ◽  
Structure Optimization ◽  
Membered Ring ◽  
Aromatic Rings ◽  
Functional Theory ◽  
Type Interaction

Within the limitations of density functional theory, the π-π type interaction between melatonin (a nocturnal hormone) and FOX-7 (an insensitive explosive) is investigated. Two composite structures have been considered in which 6- and 5-membered aromatic rings of melatonin are π-π linked to FOX-7 molecule. The structure optimization has been achieved at the level of B3LYP/6-31++G(d,p). The composite formed through the 5 membered ring of melatonin is found more stable than the composite involving 6 membered ring of melatonin and both of them are more stable than the composite having no π-π type interaction. Various structural, energetic, quantum chemical and spectral properties of the composites have been reported and discussed.

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