Resonance Raman and absorption infrared with density functional theory studies of Fe(III)/Fe(II) and Ni(II) complexes of modified 21-oxaporphyrins

2013 ◽  
Vol 17 (04) ◽  
pp. 289-308 ◽  
Author(s):  
Mateusz Fościak ◽  
Edyta Proniewicz ◽  
Krzysztof Zborowski ◽  
Younkyoo Kim ◽  
Leonard M. Proniewicz
Keyword(s):  
Density Functional ◽  
Theoretical Calculations ◽  
Resonance Raman ◽  
Vibrational Analysis ◽  
Basis Set ◽  
Functional Theory ◽  
B3lyp Level ◽  
Ft Ir ◽  
Optimized Geometries ◽  
Good Agreement

This work presents a complete vibrational analysis of iron [ Fe (II) and Fe (III)] and nickel [ Ni (II)] complexes with 5,10,15,20-tetraphenyl-21-oxaporphyrin [OTPPH] and 5,20-bis(p-tolyl)-10,15-diphenyl-21-oxaporphyrin [ODTDPPH]. In these porphyrins, a furan ring replaces one of the pyrrole rings. The six-coordinate (OTPP) FeIIICl2 and (ODTDPP) FeIIICl2 as well as the five-coordinate (OTPP) FeIICl and (OTPP) NiIICl complexes were investigated using experimental and theoretical methods. The experimental part of this work involved Fourier-transform absorption infrared (FT-IR), resonance Raman (RR), and electron absorption (UV-vis) measurements for all of the investigated complexes. In the theoretical section, optimized geometries and vibrational frequencies for model compounds are provided. The theoretical calculations were performed at the B3LYP level with the LANL2DZ basis set. Good agreement was achieved between the experimental and theoretical vibrational spectra. In addition, charge distributions (GAPT) and geometrical aromaticity indices (Bird's I5 and HOMA) were calculated and discussed.

Vibrational analysis of Ni(II) complex with 4,12-ditolyl-16,24-diphenyl-3-thiaporphyrin (SDTDPPNi(II)Cl) and its isotopic labeled (61Ni(II), −d6, and −d10) derivatives

2007 ◽  
Vol 11 (09) ◽  
pp. 652-675 ◽  
Author(s):  
Edyta Podstawka ◽  
Mateusz Fościak ◽  
Piotr Chmielewski ◽  
Leonard M. Proniewicz
Keyword(s):  
Theoretical Calculations ◽  
Geometry Optimization ◽  
Vibrational Analysis ◽  
Chloride Complex ◽  
Basis Set ◽  
B3lyp Level ◽  
Model Molecule ◽  
Polar Tensor ◽  
Ft Ir ◽  
Point Groups

This work presents complete vibrational analysis of a chloride complex of Ni (II) 4,12-ditolyl-16,24-diphenyl-3-thiaporphyrin ( SDTDPPNi (II) Cl ) and its isotopic derivatives (61 Ni (II), − d 6, and −d 10). Five-coordinate SDTDPPNi (II) Cl , SDTDPP 61 Ni (II) Cl , ( SDTDPP - d 6) Ni (II) Cl , and ( SDTDPP - d 10) Ni (II) Cl were investigated by Fourier-Transform infrared (FT-IR), resonance Raman (RR), and electronic absorption (UV-vis) methods. Because the methyl groups of tolyl rings at the para-position have negligible influence on geometry and vibrational spectra of SDTDPPNi (II) Cl , they can be treated as point groups. Thus, geometry optimization and vibrational frequencies were calculated for the 4,12,16,24-tetraphenyl-3-thiaporphyrin ( STPPNi (II) Cl ) model molecule and its isotopically labeled analogs using Gaussian'03. Moreover, charge distributions (General Atomic Polar Tensor – GAPT) and geometrical aromaticity indexes (Bird's I 5 and Harmonic Oscillator Model of Aromaticity – HOMA) were calculated. All theoretical calculations were performed at the B3LYP level with the LANL2DZ basis set. As is shown, the experimental FT-IR and RR spectra for each compound are reproduced well by the corresponding theoretical spectra.

Synthesis of New α-Amino Phosphonates Containing 3-Amino-4(3H) Quinazolinone Moiety as Anticancer and Antimicrobial Agents: DFT, NBO, and Vibrational Studies

2018 ◽  
Vol 15 (2) ◽  
pp. 286-296 ◽  
Author(s):  
Mohamed K. Awad ◽  
Mahmoud F. Abdel-Aal ◽  
Faten M. Atlam ◽  
Hend A. Hekal
Keyword(s):  
Biological Activity ◽  
Cell Line ◽  
Quantum Chemical ◽  
Density Functional ◽  
Carcinoma Cell ◽  
Liver Carcinoma ◽  
Anticancer Activities ◽  
Functional Theory ◽  
Ft Ir ◽  
Good Agreement

Aim and Objective: Synthesis of new .-aminophosphonates containing quinazoline moiety through Kabachnik-Fields reaction in the presence of copper triflate catalyst [32], followed by studying their antimicrobial activities and in vitro anticancer activities against liver carcinoma cell line (HepG2) with the hope that new anticancer agents could be developed. Also, the quantum chemical calculations are performed using density functional theory (DFT) to study the effect of the changes of molecular and electronic structures on the biological activity of the investigated compounds. Materials and Method: The structures of the synthesized compounds are confirmed by FT-IR, 1H NMR, 13C NMR, 31P NMR and MS spectral data. The synthesized compounds show significant antimicrobial and also remarkable cytotoxicity anticancer activities against liver carcinoma cell line (HepG2). Density functional theory (DFT) was performed to study the effect of the molecular and electronic structure changes on the biological activity. Results: It was found that the electronic structure of the substituents affects on the reaction yield. The electron withdrawing substituent, NO2 group 3b, on the aromatic aldehydes gave a good yield more than the electron donating substituent, OH group 3c. The electron deficient on the carbon atom of the aldehydic group may increase the interaction of the Lewis acid (Cu(OTf)2) and the Lewis base (imine nitrogen), and accordingly, facilitate the formation of imine easily, which is attacked by the nucleophilic phosphite species to give the α- aminophosphonates. Conclusion: The newly synthesized compounds exhibit a remarkable inhibition of the growth of Grampositive, Gram-negative bacteria and fungi at low concentrations. The cytotoxicity of the synthesized compounds showed a significant cytotoxicity against the liver cancer cell line (HepG 2). Also, it was shown from the quantum chemical calculations that the electron-withdrawing substituent increases the biological activity of the α-aminophosphonates more than the electron donating group which was in a good agreement with the experimental results. Also, a good agreement between the experimental FT-IR and the calculated one was found.

scholarly journals Stability and magnetic properties of isomorphous substituted Si7-xMnx+

2018 ◽  
Vol 56 (1) ◽  
pp. 64
Author(s):  
Nguyen Thanh Tung ◽  
Nguyen Thi Mai ◽  
Ngo Tuan Cuong
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Magnetic Moment ◽  
Density Functional ◽  
Basis Set ◽  
Pentagonal Bipyramid ◽  
Functional Theory ◽  
Electronic Configurations ◽  
Method Of Density Functional ◽  
Optimized Geometries

The optimized geometries, stability, and magnetic properties of cationic clusters Si7+, Si6Mn+, and Si5Mn2+ have been determined by the method of density functional theory using the B3P86/6-311+G(d) functional/basis set. Their electronic configurations have been analyzed to understand the influence of substituting Si atoms by Mn atoms on the structural and magnetic aspects of Si7+. It is shown that the manganese dopant does not alter the structure of the silicon host but significantly changes its stability and magnetism. In particular, while the magnetic moment of Si7+ is 1 mB, Si5Mn2+ exhibits a strong magnetic moment of 9 mB and that of Si6Mn+ takes a relatively high value of 4 mB. Among studied clusters, the pentagonal bipyramid Si5Mn2+ is assigned as the most stable one.

scholarly journals 1,3-Di(hetero)aryl-7-substituted Pyrenes—An Undiscovered Area of Important Pyrene Derivatives

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 28
Author(s):  
Dawid Zych
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Basis Set ◽  
Functional Theory ◽  
Td Dft ◽  
Pyrene Derivatives ◽  
Osmium Complexes ◽  
The Subject ◽  
Theoretical Considerations

In this work, the necessity of synthesis of 1,3-di(hetero)aryl-7-substituted pyrenes is presented based on the results of theoretical calculations by using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) by using Gaussian 09 program with B3LYP exchange-correlation functional and 6-31G** basis set. What is more, the synthetic routes with feasible reagents and conditions are presented. The subject of theoretical considerations are two pyrene derivatives which contain at position 1 and 3 pyrazolyl substituents and at position 7 amine (1) or boron (2) derivative. The theoretical calculations were also performed for the osmium complexes with mentioned ligands (3 and 4). The influence of electron-donating/accepting character of the substituent at position 7 of pyrene on the properties of molecules has been established.

scholarly journals Molecular Geometry, NLO, MEP, HOMO-LUMO and Mulliken Charges of Substituted Piperidine Phenyl Hydrazines by Using Density Functional Theory

2019 ◽  
Vol 32 (2) ◽  
pp. 401-407
Author(s):  
M. Dinesh Kumar ◽  
P. Rajesh ◽  
R. Priya Dharsini ◽  
M. Ezhil Inban
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Molecular Geometry ◽  
Basis Set ◽  
Functional Theory ◽  
B3lyp Method ◽  
Reactivity Descriptor ◽  
Homo Lumo ◽  
Optimized Geometries

The quantum chemical calculations of organic compounds viz. (E)-1-(2,6-bis(4-chlorophenyl)-3-ethylpiperidine-4-ylidene)-2-phenyl-hydrazine (3ECl), (E)-1-(2,6-bis(4-chlorophenyl)-3-methylpiperidine-4-ylidene)-2-phenylhydrazine (3MCl) and (E)-1-(2,6-bis(4-chloro-phenyl)-3,5-dimethylpiperidine-4-ylidene)-2-phenylhydrazine (3,5-DMCl) have been performed by density functional theory (DFT) using B3LYP method with 6-311G (d,p) basis set. The electronic properties such as Frontier orbital and band gap energies have been calculated using DFT. Global reactivity descriptor has been computed to predict chemical stability and reactivity of the molecule. The chemical reactivity sites of compounds were predicted by mapping molecular electrostatic potential (MEP) surface over optimized geometries and comparing these with MEP map generated over crystal structures. The charge distribution of molecules predict by using Mulliken atomic charges. The non-linear optical property was predicted and interpreted the dipole moment (μ), polarizability (α) and hyperpolarizability (β) by using density functional theory.

On the role of lysine in the active site Ser-X-X-Lys region of penicillin-recognizing enzymes

2010 ◽  
Vol 88 (1) ◽  
pp. 1-4
Author(s):  
Saul Wolfe ◽  
Kiyull Yang
Keyword(s):  
Active Site ◽  
Active Sites ◽  
Density Functional ◽  
Basis Set ◽  
Penicillin G ◽  
Hydroxyl Group ◽  
Functional Theory ◽  
One Step ◽  
Optimized Geometries

Using Autodock, docking of penicillin G to the crystal structures of penicillin-recognizing enzymes leads to an alignment in the active site Ser-X-X-Lys region consisting of the serine hydroxyl group, the terminal amino group of lysine, a second hydroxyl group, and the N–C=O of the β-lactam. This alignment is consistent with the notion that acylation of the serine hydroxyl group proceeds by a one-step cooperative mechanism in which C–O bond formation and proton transfer to the β-lactam nitrogen take place through a heteroatom bridge. For the cooperative ring opening of penam by two molecules of methanol and one molecule of methylamine or one molecule of water, density functional theory with the B3LYP DFT gradient-corrected functional and the 6–31G(d) basis set reproduces the alignment seen in the docked structures. Methylamine lowers the barrier calculated at MP2/6–31G(d) from the DFT-optimized geometries by 3 kcal/mol; water increases the barrier by 4 kcal/mol. The function of the conserved lysine in the active sites of penicillin-recognizing enzymes is therefore to catalyze the formation of an acyl enzyme by a cooperative mechanism.

A DENSITY FUNCTIONAL THEORY INVESTIGATION ON THE TAUTOMERS AND CRYSTAL OF 2-DIAZO-4,6-DINITROPHENOL

2004 ◽  
Vol 03 (04) ◽  
pp. 599-607 ◽  
Author(s):  
XUE-HAI JU ◽  
HE-MING XIAO
Keyword(s):  
Density Functional ◽  
Density Functional Method ◽  
Lattice Energy ◽  
Functional Method ◽  
Basis Set ◽  
Functional Theory ◽  
Basis Set Superposition Error ◽  
Conduction Bands ◽  
Valence Bands ◽  
Good Agreement

Density functional method was applied to the study of the highly efficient primary explosive 2-diazo-4,6-dinitrophenol (DDNP) in both gaseous tautomers and its bulk state. Two stable tautomers were located. It was found that the structure (I) with open diazo, i.e. with linear CNN, is more stable than that with diazo ring tautomer (II) of DDNP. The structure I is in good agreement with the structure in the bulk. The lattice energy is -89.01 kJ/mol, and this value drops to -83.29 kJ/mol when a 50% correction of the basis set superposition error was adopted. The frontier bands are quite flat. The carbon atoms in DDNP make up the upper valence bands. While the lower conduction bands mainly consist of carbon and diazo N atoms. The bond populations of C–N bonds (both C–Nitro and C–Diazo) are much less than those of the other bonds and the detonation may be initiated through the breakdown of C–N bonds.

Electronic Structure, Nonlinear Optical Properties, and Vibrational Analysis of Ethyl benzoate by Density Functional Theory

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Tanveer Hasan ◽  
P. K. Singh
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Vibrational Analysis ◽  
Ethyl Benzoate ◽  
Computational Method ◽  
Basis Set ◽  
Vibrational Modes ◽  
Normal Coordinate ◽  
Functional Theory ◽  
Vibrational Bands

This work deals with the vibrational spectroscopy of Ethyl benzoate (C9H10O2). The fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT) using standard HF/6-31G(d,p) and B3LYP/6-31G(d,p) methods and basis set combinations. The vibrational spectra were interpreted, with the aid of normal coordinate analysis based on a scaled quantum mechanical force field. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes.

Vibrational spectroscopic and conformational studies of 1-(4-pyridyl)piperazine

2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Özgür Alver ◽  
Mustafa Şenyel
Keyword(s):  
Density Functional ◽  
Structural Parameters ◽  
Density Functional Theory Method ◽  
Basis Set ◽  
Stable Form ◽  
Functional Theory ◽  
B3lyp Method ◽  
Ft Ir ◽  
Hybrid Density Functional ◽  
Ir And Raman

AbstractPossible stable conformers of the 1-(4-pyridyl)piperazine (1-4pypp) molecule were experimentally and theoretically studied by FT-IR and Raman spectroscopy. FT-IR and Raman spectra were recorded in the region of 4000–200 cm−1. Optimized geometric structures related to the minimum on the potential energy surface were investigated by the B3LYP hybrid density functional theory method using the 6-31G(d) basis set. Comparison of the experimental and theoretical results indicates that the density functional B3LYP method provides satisfactory results for the prediction of vibrational wavenumbers and structural parameters and equatorial-equatorial (e-e) isomer is supposed to be the most stable form of the 1–4pypp molecule.

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