MP2, DFT and ab initio calculations on thioxanthone

The structural, spectral, frontier molecular orbital and thermodynamic analysis of 2-hydroxy 2-methyl propiophenone by MP2 and B3LYP methods

In the present work, we have studied the 2-hydroxy 2-methyl propiophenone (2H2MPP) theoretically as well as experimentally. The optimized molecular structure has been obtained by the density functional theory (DFT), second-order Moller–Plesset perturbation theory (MP2) and Hartree Fock (HF) in the gas phase as well as in different media like ethanol, DMSO and heptane. FT-IR and FT-Raman spectra were computed as well as recorded and fundamental vibrational wavenumbers were assigned. The electronic absorption spectra were calculated by employing the time-dependent density functional theory (TD-DFT) to get the information about excitation energies, oscillator strength and excited state geometries in gas phase and in different solvent media. Chemical activity and chemical stability obtained by HOMO-LUMO studies using a HF/6-31[Formula: see text]G and MP2/6-311[Formula: see text]G calculations. The chemical interpretation of hyperconjugation interactions obtained by the Natural Bond Orbital (NBO) analysis. Moreover, electrostatic potential (ESP) calculations performed to get the visual representation of relative polarity of molecule. Thermodynamic parameters like enthalpy, entropy, heat capacity, and Gibbs free energy computed with varying temperature from 10[Formula: see text]K to 500[Formula: see text]K. The aim of the current investigation is to find out the quantum chemical properties of the title compound which show an active role in the pharmaceutical and printing industries.

Allyl amino-thioxanthone derivatives as highly efficient visible light H-donors and co-polymerizable photoinitiators

Allyl-amino thioxanthone derivatives as new visible-light photoinitiators for efficient free-radical, cationic and thiol–ene polymerizations.

Molecular structure, spectroscopic (FT-IR, FT-Raman), NBO analysis of N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine

In the present work, we have synthesized and reported a combined experimental and theoretical study on the molecular structure, vibrational spectra and HOMO-LUMO analysis of N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine (C20N6H22). The FT-IR and FT-Raman spectra of N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine were recorded. The molecular geometry, harmonic vibrational wavenumbers and bonding features of the title molecule in the ground-state have been calculated by using the density functional B3LYP method with 6-31G(d) as basis set. Non-linear optical (NLO) behavior of the N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine was investigated by determining the electric dipole moment μ, polarizability α, and hyperpolarizability β using the above mentioned basis set. The molecular properties such as ionization potential, electro-negativity, chemical potential, electrophilicity have been deduced from HOMO-LUMO analysis employing the same basis set. The calculated HOMO and LUMO energies showed that charge transfer occurs within the molecule. Stability of the molecule arising from hyper conjugative interaction and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Finally, the calculation results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with the observed spectra.

Theoretical investigations on the molecular structure, vibrational spectral, HOMO-LUMO and NBO analysis of 9-[3-(Dimethylamino)propyl]-2-trifluoro-methyl-9H-thioxanthen-9-ol

The experimental FT-IR and FT-Raman spectra of 9-[3-(Dimethylamino)propyl]-2-trifluoro-methyl-9H-thioxanthen-9-ol have been recorded. Quantum chemical calculations of geometry and vibrational wavenumbers of 9-[3-(Dimethylamino)propyl]-2-trifluoro-methyl-9H-thioxanthen-9-ol are carried out theoretically. Four possible stable conformations of the title compound were determined. In terms of the conformational analysis, one of the most interesting structural features of the title compound is the intra molecular OH⋯N hydrogen bond. The barrier of planarity between the most stable and planar form is also predicted. The optimized geometrical parameters obtained by B3LYP method show a good agreement with XRD data. The difference between the observed and theoretical wavenumbers is very small. The complete assignments were performed on the basis of potential energy distribution of the vibrational modes calculated theoretically. The calculated HOMO and LUMO energies allow the calculation of atomic and molecular properties and they also showed that charge transfer occurs in the molecule. A detailed molecular picture of the title compound and its interactions were obtained from NBO analysis. As seen from the MEP map, negative potential regions are over the hydroxyl group and positive potential regions are over the methyl groups.