Edited by

Rehab Majed Kubba
Department of Chemistry, College of Science, University of Baghdad, Baghdad, Iraq.

ISBN 978-93-91882-61-7 (Print)
ISBN 978-93-91882-62-4 (eBook)
DOI: 10.9734/bpi/mono/978-93-91882-61-7

This book dealt with application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs. The contributions by the authors include character table of D7h molecule, geometry, electronic properties, modes of vibration frequencies of Mono, Di, Tri, and Tetra rings layer of Zigzag SWCNT. Corrosion inhibition efficiency (% IE), for the surface of carbon steel in salty and acidic media by different concentrations of new organic compounds as corrosion inhibitors was studied using potentiometric polarization measurements. The results were predicted in advance through theoretical calculations using the semiempirical quantum mechanical approximate calculations of the PM3 theory and the basic calculations of the theory of density functions DFT at the computation level (B3LYP) 6-311++G (2d,2p) by the Gaussian-09 program. The book also includes unrestricted (UDFT) and (UPM3) quantum mechanical calculations for studying the reaction path of bonds rupture energies of (O-R) and (C-OAr) in diclofenac derivatives of different substituted organic groups as prodrug carriers. This book contains various materials suitable for students, researchers and academicians.

 

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Contents


Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs

Rehab Majed Kubba

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 1
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH0

Ab initio quantum chemistry is based solely on established laws of nature: Over the last two decades powerful molecular modeling tools have been developed which are capable of accurately predicting structures, energetics, reactivity and other properties of molecules. Computational chemistry is not a replacement for experimental studies, but plays an important role in enabling chemists to:

Explain and rationalise known chemistry, explore new or unknown chemistry, many molecular properties can be computed, these include; Bond energies and reaction energies, structures of ground-excited-and transition-states, atomic charges and electrostatic potentials, vibrational frequencies (IR and Raman), transition energies and intensities for UV and IR spectra, NMR chemical shifts, dipole moments, polarisabilities and hyperpolarisabilities, reaction pathways and mechanisms

This book was focused on three applications to show the importance of quantum chemistry calculations in chemical applications supporting experimentation.

The first application was for the electrical, chemical properties, vibration frequencies, and absorption intensities of SWCNTs which vary significantly according to the symmetry, chirality, and diameter, making the experimental determination of these structural properties important. The vibrational density of states contains information on the structure of carbon nanotubes, particularly at low frequencies. The signicant changes in the frequencies and relative intensities of these peaks open up a route to distinguish among structurally di-erent nanotubes. With our results, more structural information can be obtained from experiments.

The second application is the initial evaluation for the inhibition ability of new organic compounds as inhibitors towards carbon steel corrosion in acidic or basic solutions, using the quantum mechanical method of PM3 and Density Functional Theory (DFT) of B3LYP with a level of 6-311++G (2d, 2p) to calculate the geometrical structure, physical properties, and inhibition efficiency parameters, in a different media, all calculated at the equilibrium geometry. The results correlated with the experimental %IE. The local reactivity has been studied through Mulliken charges population analysis.

The third application concerns the using of suggested new prodrug designs for improving active drug solubility and consequently bioavailability, increasing permeability and absorption and modifying the drug’s distribution profile with enhanced efficacy, reduced toxicity, and side effects. Over the years, innovations in new drug therapy have become, more complex, time-consuming and costly. Theoretically in our prodrug design, a computational approach were performed by Gaussian 09 program. A comparison was made between the total energy of the reactants and the energies and transitional states up to the final products. The theoretical study of the proposed primary drugs aims to study the possibility of improving the properties of prodrugs and to study the possibility of obtaining new alternatives to approved prodrugs. Correlations between experimental and calculated values were to verify and confirm the possibility of adopting the final results.

Construct the Character Table of D\({_7}{_h}\) Point Group and Apply it for Classify the (3N-6) Modes of Vibration for the [7] Cyclacene (Linear) Monoring Molecule

Rehab Majed Kubba

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 2-14
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH1

The character table or the table of eigen values for the D7h point group, which is not found in the literature was constructed. The constructed table is used to classify all modes of the vibrational frequencies of the IR and Raman spectra for any compound or molecule that has the D7h symmetry in the Point Group. For that, it was used for classifying all the modes of vibrational frequencies of the [7] cyclacene (linear) monitoring molecule, possessing D7h symmetry. The constructed table was used to classify the symmetry species for the total degrees of freedom, total degrees of transition, total degrees of rotation and for the total degrees of modes of vibration (3N-6) for this tube. The character table was also used to determine the active and inactive  modes of vibration in the IR and Raman spectra. Also, determining the polarized and non-polarized vibrational frequencies in the Raman spectrum, and used for describing the complete physical structure of the studied molecule after extracting its geometric shape. The methods of quantum mechanics calculations PM3 and DFT were used for this purpose applying the Gaussian 09 program.

Theoretical Study of Electronic Properties and Vibration Frequencies for Tri-Rings Layer (6, 0) Linear (Zigzag) SWCNT

Rehab Majed Kubba, Khalida Aubead Samawi

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 15-27
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH2

DFT (3-21G, 6-31G and 6-311G/ B3LYP) and Semi-empirical PM3 methods were applied for calculating the vibration frequencies and absorption intensities for normal coordinates (3N-6) of the Tri-rings layer (6,0) Zigzag single wall carbon nanotube (SWCNT) at their equilibrium geometries which was found to have D6h symmetry point group with C-C bond alternation in all tube rings. As well as mono ring layer. Assignments of the modes of vibration were done depending on the pictures of their modes applying by Gaussian 03 program. The whole relations for the vibration modes were also done including (CH stretching, \(\nu\)CC stretching, deformation in plane of the molecule (\(\delta\)CH, \(\delta\)ring and \(\delta\)CCC), deformation out of plane of the molecule (\(\gamma\)CH and gring (\(\gamma\)CCC). Also include the assignment of puckering, breathing and clock-anticlockwise bending vibrations. Comparison for the geometry (the relations for axial bonds, which are the vertical C-C bonds (linear bonds) in the rings layer and for circumferential bonds which are the outer ring bonds), electronic properties and IR active vibration frequencies (asymmetric modes) of (Mono and Tri) rings layer were done. Clear relationships were found in the results of an odd layer number (Mono and Tri-rings layer). The theoretical results allow a comparative view of the charge density at the carbon atoms too.

Geometry, and Normal Modes of Vibration (3N-6) for Di and Tetra- Rings Layer (6, 0) Linear (Zigzag) SWCNTs; A DFT Treatment

Rehab M. Kubba, Khalida A. Samawi

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 28-44
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH3

Density Functional Theory (DFT) method of the type (B3LYP) and a Gaussian basis set (6-311G) were applied for calculating the vibration frequencies and absorption intensities for normal coordinates (3N-6) at the equilibrium geometry of the Di and Tetra-rings layer (6, 0) zigzag single  wall  carbon nanotubes (SWCNTs) by using Gaussian-09 program. Both were found to have the same symmetry of D6d point group with C--C bond alternation in all tube rings (for axial bonds, which are the vertical C--Ca bonds in rings layer and for circumferential bonds C—Cc in the outer and mid rings bonds). Assignments of the modes of vibration IR active and inactive vibration frequencies (symmetric and asymmetric modes) based on the image modes applied by the Gaussian 09 display. The whole relations for the vibration modes were also done including \(\nu\)CH stretching, \(\nu\)C--C stretching, \(\delta\)CH, \(\delta\)ring (\(\delta\)C--C--C) deformation in plane of the molecule) and \(\gamma\)CH, \(\gamma\)ring (\(\gamma\)C--C--C) deformation out of plane of the molecule. The assignment also included modes of puckering, breathing and clock-anticlockwise bending vibrations.

Theoretical Study of Bonds Length, Energetic and Vibration Frequencies for Construction Units of (6,0) ZigZag SWCNTs

Rehab Majed Kubba, Khalida Abaid Samawi

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 45-59
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH4

Density Functional Theory (DFT) calculation of the type (B3LYP) and 6-311G basis set level using Gaussian-03 program were carried out for equilibrium geometry of construction units of (6,0) linear ZigZag SWCNT (mono, Di, Tri and Tetra ring layers), to evaluate the geometrical structure (bond length), symmetries, physical properties and energetic such as standard heat of formation (\(\Delta\)H0f), total energy (Etot.), dipole moment (\(\mu\)), Highest Occupied Molecular Orbital Energy (EHOMO), Lowest Unoccupied Molecular Orbital Energy (ELUMO), energy gap (\(\Delta\)EHOMO-LUMO), the distribution of electron density (\(\rho\)) and vibration frequencies, all at their equilibrium geometries. Assignment of the vibration frequencies according to the group theory was done applying the Gauss View program. Comparison were done for the distribution of electron density, vibration frequencies with the studying the relationship of all the physical and electronic properties for ZigZag SWCNTs with its construction units.

DFT, PM3, AM1, and MINDO/3 Quantum Mechanical Calculations for Some INHC Cs Symmetry Schiff Bases as Corrosion Inhibitors for Mild Steel

Rehab Majed Kubba, Fatin Kareem Abood

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 60-79
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH5

Density Functional Theory (DFT) at the B3LYP/ 6-311G basis set level and semiemperical methods (PM3, AM1, and MINDO/3) were performed on six new substituted Schiff bases derivatives of INHC (N-(3-(phenylidene-allylidene) isonicotinohydrazide) using Gaussian-03 program. The calculated quantum chemical parameters correlated to the inhibition efficiency were studied and discussed at their equilibrium geometry and their correct symmetry (Cs). Comparisons of the order of inhibition efficiency of the Schiff bases derivatives, and local electrophilic and nucleophilic reactivity have analyzed. Some physical properties also were studied such as heat of formation, total energy and dipole moment...etc. Also vibration frequencies and IR absorption intensities were carried out for the calculated Schiff bases molecules.

Theoretical Study of a New Oxazolidine -5- One Derivative as a Corrosion Inhibitor for Carbon Steel Surface

Rehab Majed Kubba, Nada Mohammed Al-Joborry

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 80-88
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH6

A newly derivative of oxazolidin-5- one namely [2-(2-biphenyl-4-yl-imidazo [1,2-a] pyridine-3-yl)-3-(4-nitro-phenyl)-oxazolidin-5-one (BIPNO5)] was examined as an corrosion inhibitor for carbon steel surface. Quantum mechanical method of Density Functional Theory (DFT) with (B3LYP (6-311++G (2d, 2p)) level of theory was used to calculate the minimize structure, physical properties and inhibition chemical parameters, in vacuum and two solvents (DMSO and H2O), all at equilibrium geometry. The results indicated that the new derivative could adsorb on the surface of  carbon  steel  through the heteroatom, showing  that  the  new inhibitor has good corrosion inhibition performance.

Theoretical and Experimental Investigation of a New Imidazo (1,2-a) Pyridine Derivative as a Corrosion Inhibitor for the Carbon Steel Surface in the Saline Media

Rehab Majed Kubba, Nada Mohammed Al-Joborry

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 89-103
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH7

Using potentiometric polarisation measurements, a newly synthesised derivative of imidazo (1,2-a) pyridine, namely 2-(4-Bromo-phenyl)-2,3-dihydro-imidazo[1,2-a] pyridine-3-yl methylene]- phenyl-amine (BDIPMA), was investigated as a corrosion inhibitor for carbon steel in saline solution (3.5 percent NaCl). The thermodynamic characteristics observed in the experiments confirmed a physical adsorption mechanism, with adsorption following the Langmuir adsorption isotherm. The optimised structure, chemical inhibition efficiency parameter (percent IE), and physical properties in vacuum and two solvents (DMSO and H2O), all at the equilibrium geometry, were calculated using the quantum mechanical method of the Density Functional Theory (DFT) of B3LYP with [6-311++G (2d, 2p)] level. SEM and AFM techniques were used to investigate the surface changes of carbon steel.

Theoretical and Experimental Studies for Inhibition Potentials of Imidazolidine 4-One and Oxazolidine 5-One Derivatives for the Corrosion of Carbon Steel in Sea Water

Rehab M. Kubba, Nada M. Al-Joborry, Naeemah J. Al-Lami

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 104-124
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH8

Two derivatives of Iimidazolidin 4-one (IMID4) and Oxazolidin 5-one (OXAZ5), were investigated as corrosion inhibitors of corrosion carbon steel in sea water by employing the theoretical and experimental methods. The results revealed that they inhibit the corrosion process and their %IE followed the order: IMID4 (89.093%) > OXAZ5 (80.179%). The %IE obtained via theoretical and experimental methods were in a good agreement with each other. The thermodynamic parameters obtained by potentiometric polarization measurements have supported a physical adsorption mechanism which followed Langmuir adsorption isotherm. Quantum mechanical method of Density Functional Theory (DFT) of B3LYP with a level of 6-311++G (2d, 2p) were used to calculate the geometrical structure, physical properties and inhibition efficiency parameters, in vacuum and two solvents (DMSO and H2O), all calculated at the equilibrium geometry, and correlated with the experimental %IE. The local reactivity has been studied through Mulliken charges population analysis. The morphology of the surface changes of carbon steel were studied using SEM and AFM techniques.

Theoretical and Experimental Study for Corrosion Inhibition of Carbon Steel in Salty and Acidic Media by a New Derivative of Imidazolidine 4- One

Nada Mohammed Al-Joborry, Rehab Majed Kubba

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 125-145
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH9

A new imidazolidine 4-one derivative, of namly 2-[2-(4-Bromo-phenyl)-imidazo [1,2-a] pyridine-3-yl]-3-(4-nitro-phenyl)-imidazolidine-4-one (BPIPNP) was investigated as corrosion inhibitor for carbon steel in salty (3.5% NaCl) and acidic (0.5M HCl) solutions using potentiometric polarization measurements. The results revealed that the percentage inhibition efficiencies (%IE) in the salty solution (90.67%) are greater than that in the acidic solution (83.52%). Experimentally, the thermodynamic parameters obtained have supported a physical adsorption mechanism and which followed Langmuir adsorption isotherm. Density Functional Theory (DFT) of quantum mechanical method with B3LYP 6-311++G (2d, 2p) level was used to calculate geometrical structure, physical properties and inhibition efficiency parameters, in vacuum and two solvents (DMSO and H2O), all at the equilibrium geometry. The surface changes of carbon steel were studied using Scanning Electron Microscopy SEM and Atomic Force Microscopy (AFM) techniques.

Experimental Evaluation for the Inhibition of Carbon Steel Corrosion in Salt and Acid Media by New Derivative of Quinolin-2-One

Mustafa Alaa Mohammed, Rehab Majed Kubba

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 146-159
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH10

The inhibition ability of the new derivative (quinolin-2-one), namely (1-{[5-(2-Chloro-phenylazo)-2-hydroy-benzylidene]-amino}-4,7-dimethyl-6-nitro-1H- quinolin-2-one (CPHAQ2O)) towards carbon steel corrosion in (3.5% NaCl) and (0.5M HCl) solutions were evaluated by potentiodynamic polarization at different inhibitor concentrations. Polarization curves showed that the evaluated compound acted as mixed inhibitors, and the adsorption of the evaluated inhibitor obeys the Langmuir adsorption isotherm in both salt and acid solutions. The results revealed that the percentage inhibition efficiency (%IE) in the salty solution (90.55%) is greater than that in the acidic solution (77.62%). The surface changes of the carbon steel and the film persistency of the inhibitor were studied using SEM (Scanning Electron Microscopy).

Theoretical Study to Predict the Ability to Use Different Organic Substituents as a Carrier Linkages for Diclofenac

Rehab Majed Kubba, Aisha Muthana Shanshal

Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 1 September 2021, Page 160-176
https://doi.org/10.9734/bpi/mono/978-93-91882-61-7/CH11

The research includes unrestricted (UDFT) and (UPM3) quantum mechanical calculations for studying the reaction path of bonds rupture energies of (O-R) and (C-OAr) in twelve diclofenac derivatives of different substituted organic groups. All the calculations were done at the optimize geometries in vacuum phase by using Gaussian 09 program. Comparison was done between the studied diclofenac derivatives and the standard ionic diclofenac of sodium and potassium included geometrical structures, physical properties, total energies of the reactants and products, activation energies, and transition states. The results showed that some substituted organic groups could be used to form good carrier bonds for the acidic drug diclofenac, while others were less efficient depending on the nature of the substituted carrier, and that there is a preference for carriers of the type (–R) over the carriers of the type (–Ar).