Heteroatom içeren bazı aromatik moleküllerin lineer olmayan optik ve spektroskopik özelliklerinin teorik olarak incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu tezin amacı, heteroatom içeren bazı aromatik moleküllerin taban durumunda lineer olmayan optik ve spektroskopik özelliklerini Hartree-Fock (HF) ve Becke-3-Lee-Yang-Parr (B3LYP) metotları ile farklı temel setler kullanarak incelemektir. Bu özellikleri incelemek için, 1,3,4-oksadiazol içeren iki farklı moleküler yapı kullanılmaktadır. Bu moleküllerin seçilme nedeni, bunların birçok alanda özellikle farmasötik ve optoelektronik teknolojisinde etkin materyaller olmalarıdır. Bu teknolojik uygulamalardan dolayı 1,3,4-oksadiazol içeren farklı moleküller üzerinde literatürde birçok çalışma yapılmaktadır.Lineer olmayan optik özellikleri incelemek için, 1,3,4-oksadiazol heterosiklik yapısına bağlı farklı elektron sağlayıcı ve çekici gruplardan oluşan 18 tane oksadiazol moleküler yapı (5a-f, 8a-f ve 9a-f) kullanılmıştır. Bu moleküllerde kararlı yapılar ve yapısal parametreler elde edildikten sonra, indüklenmiş dipol moment, kutuplanabilirlik, yüksek mertebeli kutuplanabilirlik, HOMO ve LUMO enerji değerleri incelenmiştir. Aynı zamanda bu enerjilerden sertlik ve elektronegatiflik parametreleri elde edilmiştir. Bu özelliklerin farklı elektron sağlayıcı ve çekici grupların etkisi ile nasıl değiştiği araştırılmıştır. Bu durumda, iyonik moleküllerde (9a-f) yük transferi etkileşimi diğer nötr moleküllerden (5a-f ve 8a-f) daha etkilidir. Daha açık şekilde ?? 1/ ? durumu elde edilmiştir.Spektroskopik özellikleri incelemek için, 7 tane farklı moleküler yapıyı gösteren 2-aril-1,3,4-oksadiazol türevleri (5a-g) çalışılmıştır. 2-aril-1,3,4-oksadiazol türevleri (5a-g) için titreşim frekansları, uyum faktörleri ve kimyasal kayma değerleri farklı modellerde hesaplanmıştır ve sonuçlar yorumlanmıştır. Sonuç olarak, kullanılan hesaplama modellerinin güvenilirliği deneysel verilerle desteklenmiştir.The aim of this thesis is to investigate nonlinear optical and spectroscopic properties of some aromatic molecules containing heteroatoms in their ground states using Hartree-Fock (HF) and Becke-3-Lee-Yang-Parr (B3LYP) methods with different basis sets. Two different molecular structures containing 1,3,4-oxadiazole are used to investigate these properties. The reason for choosing these molecules is that they are efficient materials in various fields, especially in pharmaceutical and optoelectronic technologies. Due to these technological applications, a number of studies have been performed on different molecules containing 1,3,4-oxadiazole in the literature.To investigate nonlinear optical properties, 18 molecular structures (5a-f, 8a-f ve 9a-f) which have heterocyclic 1,3,4-oxadiazole structure substituted by various electron donor and acceptor groups have been used. Having obtained optimized structures and structural parameters, induced dipole moment, polarizability, hyperpolarizability, HOMO and LUMO energy values have been investigated. Besides, the hardness and electronegativity parameters have been obtained from these energies. How these properties change with effects of different electron donor and acceptor groups have also been investigated. In this situation, the interaction of charge transfer (CT) in the ionic molecules (9a-f) is more strength than the other neutral molecules (5a-f and 8a-f). More explicitly, ?? 1/ ? has been obtained.To investigate spectroscopic properties, 2-aryl-1,3,4-oxadiazole derivatives (5a-g) represented by seven different molecular structures have been studied. The vibrational frequencies, scaling-factors and chemical shifts using different models for 2-aryl-1,3,4-oxadiazole derivatives (5a-g) have been calculated, and results have been discussed. As a result, the accuracy of computational models has been supported with experimental data

A heterocyclic compound 5-acetyl-2,4-dimethylthiazole, spectroscopic, natural bond orbital, nonlinear optical and molecular docking studies

In this work, the 5-acetyl-2,4-dimethylthiazole (C7H9NSO) molecule was studied by using the experimental UV-vis (in three different solvents) and FT-IR spectral results, and theoretically using DFT calculation method. The calculated molecular geometric parameters, vibrational wavenumbers, HOMO-LUMO energies, H-1 and C-13 NMR chemical shift values, natural bond orbitals, and nonlinear optical properties of the 5-acetyl-2,4-dimethylthiazole (C7H9NSO) molecule at the B3LYP/and HSEH1PBE/6-LanL2DZ levels of the theory. The spectral results obtained from the quantum chemical calculations of the title compound are in a good agreement with the experimental results. Additionally, molecular docking studies were carried out to show vascular endothelial growth factor and beta-ketoacyl-acyl carrier protein synthase III inhibitory effect of 5-acetyl-2,4-dimethylthiazole. Molecular docking studies indicated that 5-acetyl-2,4-dimethylthiazole has potency to be used as an antiproliferative and antibacterial agent

Melamin diborat molekülünün molekül yapısının ve titreşim frekanslarının teorik olarak incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.ÖZET Anahtar kelimeler: Melamin diborat; İR spektrumu; DFT; HF; Titreşim işaretleme; Triazin halkası. Temel halde bulunan melamin diborat'ın titreşim frekansları ve geometrik yapısı Hartree-Fock ve yoğunluk fonksiyonu metodu (B3LYP) ile 6-31G(d) temel seti kullanılarak hesaplanmıştır. HF ve DFT (B3LYP) kullanılarak elde edilen optimumlaştırılmış geometrik bağ uzunlukları ve bağ açıları deneysel verilerle iyi bir uyumluluk göstermektedir. Hartree-Fock ve yoğunluk fonksiyonu metodu (B3LYP) ile hesaplanan sonuçlar, melamin diborat'ın gözlenen temel titreşim frekansları ile karşılaştırıldığında B3LYP molekül er titreşim problemleri için hesaplanan Hartree- Fock yaklaşımına göre daha üstündür. XIVTHEORETICAL INVASTIGATION OF MOLECULAR STRUCTURE AND VIBRATIONAL SPECTRA OF MELAMINE DIBORATE MOLECULE SUMMARY Keywords : Melamine diborate; IR spectrum; DFT; HF; Vibrational assignment; Triazine ring. The molecular geometry and vibrational frequencies of melamine diborate in the ground state have been calculated using the Hartree-Fock and density functional method (B3LYP) with 6-31G(d) basis set. The optimized geometric bond lengths and bond angles obtained by using HF and DFT (B3LYP) show the best agreement with the experimental data. Comparison of the observed fundamental vibrational frequenies öf melamine diborate with calculated results by density functional B3LYP and Hartree-Fock methods indicate that B3LYP is superior to the scaled Hartree- Fock approach for molecular vibrational problems. X

Effect of temperature on the solubility of 3-aminopyridine in binary ethanol + toluene solvent mixtures (vol 316, pg 132, 2012)

The authors regret that in the above cited article, Table 4 was changed. The authors of above article formed Table 4 using the Eq. (8), the apparent molar enthalpies of 3-aminopyridine [in ethanol (w) + toluene (1–w) solvents (w = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) are (57.11, 21.34, 16.19, 14.45, 13.21, and 11.98) kJ mol−1] and Table 3 (the apparent molar Gibbs energy, kJ mol−1)

Second and third-order nonlinear optical properties and molecular parameters of azo chromophores: Semiempirical analysis

The static and frequency dependent average polarizability (). first- and second-hyperpolarizabilities ( and ) and highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO) energies of nonlinear optical chromophores with nitro acceptors 1-5 have been investigated by using the Austin Model 1 (AM1), Modified Neglect of Diatomic Overlap (MNDO), MNDO with d orbitals (MNDO-d), Parameterization Method 3 (PM3), Recife Model 1 (RM1) and Parameterization Method 6 (PM6) methods within a time-dependent Hartree-Fock (TDHF) approaches. The electronic properties of chromophores 1-5 have been reported by employing two-state model calculated at Zerner's spectroscopic version of the Intermediate Neglect of Differential Overlap singly excited configuration interaction (ZINDO/S-SCI) method. Also, the molecular hardness (eta and electronegativity (chi) parameters have been obtained by using molecular frontier orbital energies. The , , HOMO, LUMO energies, eta and chi parameters have been investigated with respect to the choice of different semiempirical methods. (C) 2011 Elsevier B.V. All rights reserved

The consistency analysis of different semiempirical calculations on second- and third-order nonlinear optical properties of donor-acceptor chromophores containing alpha-cyan

The static and frequency dependent average polarizability (), first- and second-hyperpolarizabilities ( and ) and HOMO and LUMO energies of donor-acceptor chromophores containing a-cyan (la-c) have been investigated by using the AM1, MNDO, MNDO-d, PM3, RM1 and PM6 methods within a time-dependent Hartree-Fock (TDHF) approaches. The electronic properties of 1a-c have been reported by employing two-state model calculated at ZINDO/S-SCI, PM3-SCI and RM1-SCI methods. Also, the molecular hardness (eta) and electronegativity (chi) parameters have been obtained by using molecular frontier orbital energies. The , , HOMO, LUMO energies, eta and chi parameters have been investigated with respect to the choice of different semiempirical methods. The variation graphics of beta, beta(0), eta and chi parameters according to the different semiempirical methods are presented. Furthermore, the variation graphics of beta(0) with regard to the mu(eg), Delta mu and lambda(eg) are displayed. The frontier molecular orbital and electrostatic potential pictures of 1a-c using ZINDO/S-SCI level have been examined. The results of 1a-c display significant second- and third-order molecular nonlinearity. (C) 2010 Elsevier B.V. All rights reserved

Molecular structure and vibrational and chemical shift assignments of 5-(2-Hydroxyphenyl)-4-(p-tolyl)-2,4-dihydro-1,2,4-triazole-3-thione by DFT and ab initio HF calculations

The molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) (1)H and (13)C chemical shift values and several thermodynamic parameters of 5-(2-Hydroxyphenyl)-4-(p-tolyl)-2,4-dihydro-1,2,4-triazole-3-thione in the ground state have been calculated by using the Hartree-Fock (HF) and density functional method (DFT/B3LYP) with 6-31G(d), 6-31 + G(d,p) and LANL2DZ basis sets. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The computed vibrational frequencies are used to determine the types of molecular motions associated with each of the experimental bands observed. Also, calculated (1)H chemical shift values compared with the experimental ones. The data of the title compound display significant molecular structure and IR, NMR analysis provide the basis for future design of efficient materials having the of 1,2,4-triazole core

Molecular structure, vibrational spectra, NLO and NBO analysis of bis(8-oxy-1-methylquinolinium) hydroiodide

In this paper, quantum chemistry calculations of geometric parameters, harmonic vibrational wavenumbers, molecular frontier orbital energies (HOMO and LUMO) and the electronic properties of bis(8-oxy-1-methylquinolinium) hydroiodide ([(C10H9NO)(2)H+]center dot 1(-)) have been performed by using Gaussian 09 program. The structural and spectroscopic data of the molecule in the ground state have been calculated by using Hartree-Fock (HF) and density functional method (DFT/B3LYP) with the LanL2DZ basis set. For the spectra predicted, a potential energy distribution (PED) is calculated. The H-1 and C-13 nuclear magnetic resonance (NMR) chemical shifts values of bis(8-oxy-1-methylquinolinium) hydroiodide molecule have been calculated by the gage including atomic orbital (GIAO) method. Furthermore, molecular electrostatic potential maps (MEP), Mulliken charges and the natural bonding orbital (NBO) analysis of the compound have been calculated by the HF and B3LYP/Lanl2DZ methods. (C) 2012 Elsevier B.V. All rights reserved

Molecular Structure, Vibrational Spectra and Chemical Shift Properties of C12H9ClO4 and C2H9BrO4 Crystals by Density Functional Theory and ab initio Hartree-Fock Calculations

The molecular geometry, vibrational spectra, and guage including atomic orbital (GIAO), individual gauges for atoms in molecules (IGAIM), and continuous set of guage transformations (CSTG) H-1 and C-13 chemical shift values of ethyl 6-chloro-2-oxo-2H-chromene-3-carboxlate (C12H9ClO4-(I)) and ethyl 6-bromo-2-oxo-2H-chromene-3-carboxylite (C12H9BrO4-(II)) in the ground state have been Calculated by Using the Hartree-Fock (HF) and density functional method (B3LYP) with 63 31G+(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The computed vibrational frequencies were used to determine the types of molecular motions associated with the spectra of the experimental hands observed. Also, calculated H-1 and C-13 chemical shift values were compared with the experimental ones