Molecular structure and vibrational frequencies of 4,4,4-trifluoro-1-phenyl-1,3-butanedione, known as trifluorobenzoylacetone (TFBA), have been investigated by means of density functional theory (DFT) calculations. The results were compared with those of benzoylacetone (BA), acetylacetone (AA), and trifluoroacetylacetone (TFAA). Comparing the calculated and experimental band frequencies and int...

Molecular structure and vibrational frequencies of 1,3-diphenyl-1,3-propanedione, known as dibenzoylmethane (DBM), have been investigated by means of density functional theory (DFT) calculations. The results were compared with those of benzoylacetone (BA) and acetylacetone (AA), the parent molecule. IR and Raman spectra of DBM and its deuterated analogue were clearly assigned. The calculated hy...

Structural and magnetic properties of purine and pyrimidine nucleotides (CMP, UMP, dTMP, AMP, GMP, IMP) were studied at different levels of ab initio molecular orbital theory. These calculations were performed at the hartree-fock level and density functional B3LYP methods. Geometries were fully optimized by following Cs symmetry restrictions. The standard 6-31G** basis set which includes polari...

Most quantum mechanical studies of triterpene synthesis have been done on small models. We calculated mPW1PW91/6-311+G(2d,p)//B3LYP/6-31G* energies for many C30H51O+ intermediates to establish the first comprehensive energy profiles for the cationic cyclization of oxidosqualene to lanosterol, lupeol, and hopen-3beta-ol. Differences among these 3 profiles were attributed to ring strain, steric e...

Density functional theory dispersion corrected (DFT-D3)calculations and molecular dynamic (MD) simulation were applied to investigate the sensing ability of four types of receptors (RCs) composed of the ortho-phenylenediamine based bis-ureas for selective complexation with the anions such as Cl–, Br–, OAC–, PhCO2–, H2PO4– and HSO4– in the gas phase and DMSO. On the basis of the data obtained fr...

The complexes between C20 and C2 X4 , C2 X2 (X = H, F, Cl, Br) have been studied theoretically at the B3LYP/6-311G (d,p) level. The calculations include the optimized geometries, the interaction energies, aromaticity and thermodynamic. The interaction energies ranging from -60 to -101 kcal/mol and being ordered as: X = F> Cl > Br. Natural bond orbital (NBO) analysis has been performed on all ge...

Enol forms of trifluoroacetylacetone (TFacac) isolated in molecular and rare gas matrices were studied using infrared (IR) Raman spectroscopy. Additionally, calculations DFT B3LYP M06...

Abstract The structure–activity relationship studied by DFT calculations and contacted with practical antimicrobial results for compounds 1–4 is discussed in detail. In light of this have been using DFT/B3LYB/6-311++G (d,p) at the level theory, geometrical parameters, bond lengths angles discussed. quantum mechanical showed that presence phosphorus sulfur atoms changed planarity parent compound...

In this study the molecular geometries, experimental vibrational and electronic absorption spectra and quantum chemical calculations of free dimethyl phenylphosphonite, (C8H11PO2), (with synonym, dimethoxyphenylphosphine or phenyldimethoxyphosphine) (Abbreviated as DMPP) and its [Cd(DMPP)].Cl2.H2O metal halide complex have been investigated by using elemental analysis, FT-IR, micro-Raman and UV...

In this paper, Exchange and Correlation energies of boron nitride with the formula of B12N12 are calculated by using the DFT methods with STO-3G, 6-31G AND 6-311G basis sets. The optimized structure and electronic properties calculations for the studied molecule have been performed using Gaussian 09 program. A mathematical equation of second grade was exploited for the correlation and exchange ...