scholarly journals Theoretical Study of Copper Complexes: Molecular Structure, Properties, and Its Application to Solar Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jesus Baldenebro-Lopez ◽  
Norma Flores-Holguin ◽  
Jose Castorena-Gonzalez ◽  
Jorge Almaral-Sanchez ◽  
Daniel Glossman-Mitnik
Keyword(s):  
Molecular Structure ◽  
Solar Cells ◽  
Density Functional ◽  
Copper Complexes ◽  
Chemical Reactivity ◽  
Polarizable Continuum Model ◽  
Basis Sets ◽  
The Density Functional Theory ◽  
Potential Applications ◽  
Implicit Approach

We present a theoretical investigation of copper complexes with potential applications as sensitizers for solar cells. The density functional theory (DFT) and time-dependent DFT were utilized, using the M06 hybrid meta-GGA functional with the LANL2DZ (D95V on first row) and DZVP basis sets. This level of calculation was used to find the optimized molecular structure, the absorption spectra, the molecular orbitals energies, and the chemical reactivity parameters that arise from conceptual DFT. Solvent effects have been taken into account by an implicit approach, namely, the polarizable continuum model (PCM), using the nonequilibrium version of the IEF-PCM model.

scholarly journals Calculations of optical rotation: Influence of molecular structure

2012 ◽  
Vol 77 (7) ◽  
pp. 887-898
Author(s):  
Jia Yu ◽  
Yu Cao ◽  
Hang Song ◽  
Xianlong Wang ◽  
Shun Yao
Keyword(s):  
Molecular Structure ◽  
Nitrogen Atom ◽  
Density Functional ◽  
Optical Rotation ◽  
Cyclic Compound ◽  
Polarizable Continuum Model ◽  
Basis Sets ◽  
Dft Methods ◽  
Hartree Fock ◽  
Chiral Compounds

Ab initio Hartree-Fock (HF) method and Density Functional Theory (DFT) were used to calculate the optical rotation of 26 chiral compounds. The effects of theory and basis sets used for calculation, solvents influence on the geometry and values of calculated optical rotation were all discussed. The polarizable continuum model, included in the calculation, did not improve the accuracy effectively, but it was superior to ?s. Optical rotation of five or sixmembered of cyclic compound has been calculated and 17 pyrrolidine or piperidine derivatives which were calculated by HF and DFT methods gave acceptable predictions. The nitrogen atom affects the calculation results dramatically, and it is necessary in the molecular structure in order to get an accurate computation result. Namely, when the nitrogen atom was substituted by oxygen atom in the ring, the calculation result deteriorated.

Study of the Stability and Chemical Reactivity of a Series of Tetrazole Pyrimidine Hybrids by the Density Functional Theory Method (DFT)

2021 ◽  
Vol 37 (4) ◽  
pp. 805-812
Author(s):  
Ahissandonatien Ehouman ◽  
Adjoumanirodrigue Kouakou ◽  
Fatogoma Diarrassouba ◽  
Hakim Abdel Aziz Ouattara ◽  
Paulin Marius Niamien
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Molecular Descriptors ◽  
Chemical Reactivity ◽  
Density Functional Theory Method ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
The Stability ◽  
Global Reactivity Descriptors

Our theoretical study of stability and reactivity was carried out on six (06) molecules of a series of pyrimidine tetrazole hybrids (PTH) substituted with H, F, Cl, Br, OCH3 and CH3 atoms and groups of atoms using the density function theory (DFT). Analysis of the thermodynamic formation quantities confirmed the formation and existence of the series of molecules studied. Quantum chemical calculations at the B3LYP / 6-311G (d, p) level of theory determined molecular descriptors. Global reactivity descriptors were also determined and analyzed. Thus, the results showed that the compound PTH_1 is the most stable, and PTH_5 is the most reactive and nucleophilic. Similarly, the compound PTH_4 is the most electrophilic. The analysis of the local descriptors and the boundary molecular orbitals allowed us to identify the preferred atoms for electrophilic and nucleophilic attacks.

The fragment molecular orbital method combined with density-functional tight-binding and the polarizable continuum model

2016 ◽  
Vol 18 (32) ◽  
pp. 22047-22061 ◽  
Author(s):  
Yoshio Nishimoto ◽  
Dmitri G. Fedorov
Keyword(s):  
Molecular Structure ◽  
Molecular Orbital ◽  
Continuum Model ◽  
Density Functional ◽  
Tight Binding ◽  
Polarizable Continuum Model ◽  
Orbital Method ◽  
Molecular Orbital Method ◽  
Polarizable Continuum ◽  
Structure Of Proteins

The electronic gap in proteins is analyzed in detail, and it is shown that FMO-DFTB/PCM is efficient and accurate in describing the molecular structure of proteins in solution.

Density functional theory (DFT) calculations on the structures and stabilities of [CnO2n+1]2– and [CnO2n+1]X2 polycarbonates containing chainlike (CO2)n units (n = 2–6; X = H or Li)

2011 ◽  
Vol 89 (6) ◽  
pp. 671-687 ◽  
Author(s):  
Pablo J. Bruna ◽  
Friedrich Grein ◽  
Jack Passmore
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Ion Pairs ◽  
Dicarboxylic Acids ◽  
Polarizable Continuum Model ◽  
Weakly Bound ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Weakly Bound Complexes

The structures and stabilities of chainlike (CO2)n (n = 2–6) polycarbonates, where adjacent C atoms are linked by C–O–C bonds, were investigated at the density functional theory (DFT) level (B3PW91/6–311G(2d,p)), including dicarboxylic dianions, [CnO2n+1]2–, and the corresponding acids, [CnO2n+1]H2, and Li salts, [CnO2n+1]Li2. At equilibrium, the most stable systems have Cs, C2, or C2v symmetries. In the gas phase, these dianions are generally metastable with respect to spontaneous ejection of one electron, yet in the presence of counterions they become stabilized, for example, as [CnO2n+1]2–(Li+)2 ion pairs. [CnO2n+1]2– linkages are also stabilized as dicarboxylic acids, [CnO2n+1]H2; we find the latter to have equilibrium conformations of higher symmetry than previously reported in the literature. To the best of our knowledge, none of the [CnO2n+1]X2 (X = Li or H) compounds with n ≥ 2 have been reported in the experimental literature (albeit, the alkyl esters C2O5R2 and C3O7R2 are commercially available). All CO bonds in C2O5X2 to C6O13X2 have single- to double-bond character (≈140–118 pm), indicating that the [CnO2n+1] moieties are held together by strong chemical forces (in contrast to the weakly bound complexes (CO2)n and (CO2)n–, n > 1). Vibrational frequencies were calculated to ensure all conformations were true minima. The IR and Raman intensities show that the high intensity C=O stretching modes (1750 ± 100 cm–1) will help in the spectral characterization of these compounds. Solvation calculations using the polarizable continuum model (PCM) find that C2O52– can be formed via CO32– + CO2 as well as CO3–[Formula: see text], each reaction having ΔG298 < 0 in practically all solvents. This result confirms the experimentally observed large solubility of CO2(g) in molten carbonates, CO3M2 (M = Li, Na, or K). In contrast, starting with n = 2, the reactions [CnO2n+1]2– + CO2 do not proceed spontaneously in any solvent (ΔG298 > 0).

scholarly journals Synthesis, X-Ray Crystallography, Thermal Analysis, and DFT Studies of Ni(II) Complex with 1-Vinylimidazole Ligand

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fatih Şen ◽  
Ramazan Şahin ◽  
Muharrem Dinçer ◽  
Ömer Andaç ◽  
Murat Taş
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Basis Sets ◽  
Mulliken Charge ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Dft Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Density Functional Theory

The paper presents a combined experimental and computational study of hexa(1-vinylimidazole)Ni(II) perchlorate complex. The complex was prepared in the laboratory and crystallized in the monoclinic space group P21/n with a=8.442(5), b=13.686(8), c=16.041(9) Å, α=γ=90, β=96.638(5), and Z=1. The complex has been characterized structurally (by single-crystal X-Ray diffraction) and its molecular structure in the ground state has been calculated using the density functional theory (DFT) methods with 6-31G(d) and LanL2DZ basis sets. Thermal behaviour and stability of the complex were studied by TGA/DTA analyses. Besides, the nonlinear optical effects (NLO), molecular electrostatic potential (MEP), frontier molecular orbitals (FMO), and the Mulliken charge distribution were investigated theoretically.

scholarly journals Crystal structure and DFT study of (E)-N-[2-(1H-indol-3-yl)ethyl]-1-(anthracen-9-yl)methanimine

2017 ◽  
Vol 73 (9) ◽  
pp. 1329-1332
Author(s):  
Md. Serajul Haque Faizi ◽  
Necmi Dege ◽  
Sergey Malinkin ◽  
Tetyana Yu. Sliva
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Density Functional ◽  
Condensation Reaction ◽  
Ring System ◽  
Two Dimensional ◽  
Indole Ring ◽  
Functional Theory ◽  
Compound C ◽  
The Density Functional Theory

The title compound, C25H20N2, (I), was synthesized from the condensation reaction of anthracene-9-carbaldehyde and tryptamine in dry ethanol. The indole ring system (r.m.s. deviation = 0.016 Å) makes a dihedral angle of 63.56 (8)° with the anthracene ring (r.m.s. deviation = 0.023 Å). There is a short intramolecular C—H...N interaction present, and a C—H...π interaction involving the two ring systems. In the crystal, the indole H atom forms an intermolecular N—H...π interaction, linking molecules to form chains along theb-axis direction. There are also C—H...π interactions present, involving the central and terminal rings of the anthracene unit, linking the chains to form an overall two-dimensional layered structure, with the layers parallel to thebcplane. The density functional theory (DFT) optimized structure, at the B3LYP/6-311 G(d,p) level, is compared with the experimentally determined molecular structure in the solid state.

DENSITY FUNCTIONAL THEORY STUDY ON THE MECHANISM OF TRIMETHYLAMINE-CATALYZED BAYLIS–HILLMAN REACTION

2010 ◽  
Vol 09 (supp01) ◽  
pp. 65-75 ◽  
Author(s):  
JING LI ◽  
WAN-YI JIANG
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dft Method ◽  
Polarizable Continuum Model ◽  
Functional Theory ◽  
Reaction Barrier ◽  
Hydrogen Shift ◽  
Rate Determining Step ◽  
The Density Functional Theory ◽  
Polarizable Continuum

The trimethylamine-catalyzed Baylis–Hillman reaction of formaldehyde and vinylaldehyde has been studied with the density functional theory (DFT) method of B3LYP/6-31+G(d,p). In the gas phase, the reaction involves an amine–formaldehyde–vinylaldehyde trimolecular addition transition structure followed by rate-determining intramolecular 1,3-hydrogen shift. When a bulk solvent effect of water was considered with conductor-like polarizable continuum model (CPCM), the reaction was found to follow the sequence of Michael-addition of amine to vinylaldehyde (step 1), addition of formaldehyde (step 2), and 1,3-hydrogen shift (step 3), with the 1,3-hydrogen shift as rate-determining. The overall reaction barrier is significantly reduced. When a molecule of water is involved in the reaction, the 1,3-hydrogen shift is significantly promoted so that the rate-determining step becomes the C–C bond formation. The calculated overall reaction barrier is in agreement with experimental observations.

THEORETICAL STUDY OF GLYCINE CONFORMERS

2008 ◽  
Vol 07 (04) ◽  
pp. 889-909 ◽  
Author(s):  
HONG-WEI KE ◽  
LI RAO ◽  
XIN XU ◽  
YI-JING YAN
Keyword(s):  
Potential Energy Surfaces ◽  
Density Functional ◽  
Polarizable Continuum Model ◽  
Basis Sets ◽  
Dft Methods ◽  
Solvent Interactions ◽  
Solvation Effects ◽  
Moller Plesset ◽  
Energy Surfaces ◽  
Polarizable Continuum

Glycine conformers were investigated with three density functional theory (DFT) methods (B3LYP, PBE1PBE, X3LYP), and the second order Møller–Plesset perturbation theory (MP2) combined with basis sets of 6-31+G*, aug-cc-pVDZ, and aug-cc-pVTZ. Solvation effects were considered by using polarizable continuum model. Results from B3LYP and X3LYP were in generally good agreement with those of MP2, while PBE1PBE was shown to be inferior for the description of conformational potential energy surfaces. Conformers Ip, IIp, IIn, IIIp, IIIn, and IVn were all found to be low-lying states within 2.0 kcal/mol, with Ip being the global minimum in gas phase. Solvation effects can significantly change the nature of the conformational surfaces of glycine. A proper description of conformational equilibrium demands for a good treatment of both long-range and short-range solute–solvent interactions.

scholarly journals THEORETICAL STUDY ON THE REACTION MECHANISM OF CO2 FORMATION FROM ACYLOXY RADICALS

2018 ◽  
Vol 55 (6A) ◽  
pp. 105
Author(s):  
Nguyen Thi Minh Hue
Keyword(s):  
Reaction Mechanism ◽  
Density Functional ◽  
Basis Sets ◽  
Free Energies ◽  
Combustion Chemistry ◽  
Functional Theory ◽  
Mechanism Of Decomposition ◽  
Energy Profiles ◽  
The Density Functional Theory ◽  
Experimental Values

The decomposition mechanism of acyloxy radicals has been studied by the Density Functional Theory (DFT) using B3LYP functional in conjunction with the 6-311++G(d,p) and 6-311++G(3df,2p) basis sets. The potential energy profiles for reaction systems were generally established. Calculated results indicate that the formation of products including hydrocarbon radicals and CO2 molecule is energetically favored. The rate of decomposition increases with the number of carbon in non-cyclic saturated acyloxy radicals. Calculated enthalpies and Gibbs free energies of reactions well agree with experimental values. This study is a contribution to the understanding of the reaction mechanism of decomposition of acyloxy radicals in atmosphere and combustion chemistry. 

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