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Book Part Kinetics of Co2 Capture by Carbon Dioxide Binding Organic Liquids(Springer international Publishing Ag, 2016) Orhan, Ozge Yuksel; Kayi, Hakan; Alper, Erdogan[No Abstract Available]Article Citation - WoS: 10Citation - Scopus: 9A Computational Study on 4,7-Di(furan Monomer and Its Oligomers(Springer, 2014) Kayi, Hakan; Kayı, Hakan; Kayı, Hakan; Chemical Engineering; Chemical EngineeringThe energy gap, Eg, between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels that determines the electronic and optical properties of 4,7-di(furan-2yl)benzo[c][1,2,5]thiadiazole (FSF) polymer is calculated by performing quantum chemical calculations. First, we theoretically investigated the most stable conformers of FSF monomer and its corresponding oligomers at the B3LYP/6-31G(d) and B3LYP/LANL2DZ levels of theory. We reveal the theoretical molecular structure of this very recently synthesized novel monomer and its oligomers for the first time in the literature. Our results from the B3LYP/6-31G(d) calculations indicated that FSF polymer has a low HOMO-LUMO gap of 1.55 eV to be in good agreement with the experiments. Experimental design and synthesis of novel conjugated polymers require time-consuming and expensive procedures. The findings from this study are promising for the use of computational methods in the design of the novel conjugated polymers, and help to narrow the materials to be used in design and synthesis of conjugated polymers with desired properties.Article Citation - WoS: 9Citation - Scopus: 10A Theoretical Investigation of 4,7-Di(furan Donor-Acceptor Type Conjugated Polymer(Elsevier, 2015) Kayi, Hakan; Elkamel, AliQuantum chemical calculations are performed using density functional theory (DFT) to investigate the HOMO-LUMO energy gap of the 4,7-di(furan-2-yl)benzo[c][1,2,5]selenadiazole-based (FSeF) donor-acceptor type conjugated polymer which ascertains the optoelectronic properties and plays a crucial role, especially in polymeric solar cell applications. In this paper, the most stable conformers of the FSeF monomer and its corresponding oligomers are investigated at the B3LYP/Def2TZV and B3LYP/LANL2DZ levels of theory, and their molecular structures are revealed. The band gap of the polymer is determined by linear-fitting and extrapolation of the DFT data. This gap is found to be 1.44 eV and 1.45 eV by the B3LYP/Def2TZV, and B3LYP/LANL2DZ with PCM calculations, respectively. Our theoretical findings related to the band gap of the FSeF polymer (PFSeF) are in good agreement with other experimental studies in the literature and, hence, the theoretical methods used in this study are promising for the design of similar donor-acceptor type novel conjugated polymers. (C) 2014 Elsevier B.V. All rights reserved.Article Citation - WoS: 3Citation - Scopus: 3Correlations Between Hardness, Electrostatic Interactions, and Thermodynamic Parameters in the Decomposition Reactions of 3-Buten 3-Methoxy and Ethoxyethene(Springer/plenum Publishers, 2015) Hasanzadeh, Neda; Nori-Shargh, Davood; Kayi, Hakan; Javid, Nargess RezaeiDecomposition of the three isomeric compounds, 3-buten-1-ol (1), 3-methoxy-1-propene (2), and ethoxyethene (3), at two different (300 and 550 K) temperatures has been investigated by means of ab initio molecular orbital theory (MP2/6-311+G**//B3LYP/6-311+G**), hybrid-density functional theory (B3LYP/6-311+G**), the complete basis set, nuclear magnetic resonance analysis, and the electrostatic model associated with the dipole-dipole interactions. All three levels of theory showed that the calculated Gibbs free energy differences between the transition and ground state structures (Delta G (not equal)) increase from compound 1 to compound 3. The variations of the calculated Delta G (not equal) values can not be justified by the decrease of the calculated global hardness (eta) differences between the ground and transition states structures (i.e., Delta[eta(GS)-eta(TS)]). Based on the synchronicity indices, the transition state structures of compounds 1-3 involve synchronous aromatic transition structures, but there is no significant difference between their calculated synchronicity indices. The optimized geometries for the transition state structures of the decomposition reactions of compounds 1-3 consist in chair-like six-membered rings. The variation of the calculated activation entropy (Delta S (not equal)) values can not be justified by the decrease of Delta[eta(GS)-eta(TS)] parameter from compound 1 to compound 3. On the other hand, dipole moment differences between the ground and transition state structures [Delta(A mu (TS)-A mu (GS))] decrease from compound 1 to compound 3. Therefore, the electrostatic model associated with the dipole-dipole interactions justifies the increase of the calculated Delta G (not equal) values from compound 1 to compound 3. The correlations between Delta G (not equal), Delta[eta(GS)-eta(TS)], (Delta S (not equal)), k(T), electrostatic model, and structural parameters have been investigated.Article Citation - WoS: 5Citation - Scopus: 7Design of Novel Tellurium and Selenium Containing Semiconducting Polymers Using Quantum Mechanical Tools(Elsevier, 2017) Kaya, Birnur; Kayi, HakanStructural, optical and electronic properties of the two novel donor-acceptor-donor type conjugated polymers based on 4,7-di(selenophen-2-yl)benzo[c][1,2,5]selenadiazole (SeSeSe) and 4,7-di(tellurophen-2-yl)benzo[c][1,2,5]telluradiazole (TeTeTe) are investigated by means of quantum chemical calculations utilizing conventional and long-range corrected hybrid functionals. The lowest energy structures of the SeSeSe and TeTeTe monomers and oligomers are revealed through conformational analysis, while their electronic properties are obtained from density functional theory (DFT) molecular orbital calculations and optical properties are obtained from the time dependent DFT (TD-DFT) calculations for UV-vis absorption spectra. Electronic band gaps that directly affect the semiconducting properties of these novel polymers are calculated by using linear regression analysis of DFT data, and also periodic boundary conditions calculations (PBC-DFT). Our results indicate that SeSeSe and TeTeTe polymers have considerably lower band gap values than that of their furan-, thiophene-, benzooxadiazole- and benzothiadiazole-based analogs. The novel SeSeSe and TeTeTe polymers with improved optical and electronic properties may have an important role in the near future, especially for the optoelectronic and photovoltaic applications. (C) 2016 Elsevier B.V. All rights reserved.Article Citation - WoS: 4Citation - Scopus: 4Anticancer Investigation of Platinum and Copper-Based Complexes Containing Quinoxaline Ligands(Elsevier, 2022) El-Beshti, Hager Sadek; Yildizhan, Yasemin; Kayi, Hakan; Cetin, Yuksel; Adiguzel, Zelal; Gungor-Topcu, Gamze; Ozalp-Yaman, SenizThis research focuses on synthesis and anticancer activity of trans-[(dichloro)bisdipyridlquinoxalino] and [(dichloro)bisdithienylquinoxalino]copper(II)/platinum(II) compounds as prodrug candidates. The binding interaction of these compounds with calf thymus DNA (CT-DNA) and human serum albumin (HSA) of the complexes were assessed with UV titration, thermal decomposition, viscometric, and fluorometric measurements. The nature of the binding of the complexes on DNA were revealed as electrostatic interaction between the cationic metal complexes ion and the negative phosphate groups of CT-DNA upon removal of the counter ion, chloride. In addition, our complexes induced a surface contact through the hydrophobic region of protein. Antitumor activity of the complexes against human glioblastoma A172, LN229, and U87 cell lines and human lung A549, human breast MDA-231, human cervix HeLa, and human prostate PC-3 cell lines were investigated by examining cell viability, oxidative stress, apoptosis, and migration/invasion. Cytotoxicity of the complexes was evaluated by MTT test. The U87 and HeLa cells were investigated as the cancer cells most sensitive to our complexes. The exerted cytotoxic effect of dipyridlquinoxalino and dithienylquinoxalino copper(II)/platinum(II) complexes was attributed to the formation of the reactive oxygen species in vitro. It is clearly demonstrated that trans-[(dichloro)bisdithenylquinoxalino]copper (II) (Cu(dtq)) has the highest DNA degradation potential and anticancer effect among the tested complexes by leading apoptosis. Wound healing and invasion analysis results also supported the anticancer activity of Cu(dtq). (C) 2021 Elsevier B.V. All rights reserved.Article Citation - WoS: 2Citation - Scopus: 3Experimental and Theoretical Investigation of the Reaction Between Co2 and Carbon Dioxide Binding Organic Liquids(Tubitak Scientific & Technological Research Council Turkey, 2016) Tankal, Hilal; Yuksel Orhan, Ozge; Alper, Erdogan; Ozdogan, Telhat; Kayi, HakanThe reaction kinetics of CO2 absorption into new carbon dioxide binding organic liquids (CO(2)BOLs) was comprehensively studied to evaluate their potential for CO2 removal. A stopped-flow apparatus with conductivity detection was used to determine the CO2 absorption kinetics of novel CO(2)BOLs composed of DBN (1,5-diazabicyclo[4.3.0]non-5-ene)/1-propanol and TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene)/1-butanol. A modified termolecular reaction mechanism for the reaction of CO2 with CO(2)BOLs was used to calculate the observed pseudo-first order rate constant k(0) (s(-1)) and second-order reaction rate constant k(2) (m(3)/kmol.s). Experiments were performed by varying organic base (DBN or TBD) weight percentage in alcohol medium for a temperature range of 288-308 K. It was found that k(0) increased with increasing amine concentration and temperature. By comparing using two different CO2BOL systems, it was observed that the TBD/1-butanol system has faster reaction kinetics than the DBN/1-propanol system. Finally, experimental and theoretical activation energies of these CO2BOL systems were obtained and compared. Quantum chemical calculations using spin restricted B3LYP and MP2 methods were utilized to reveal the structural and energetic details of the single-step termolecular reaction mechanism.Article Citation - WoS: 10Citation - Scopus: 11Capture of Carbonyl Sulfide by Organic Liquid Mixtures: a Systematic Dft Investigation(Amer Chemical Soc, 2021) Abduesslam, Mahmoud; Kayi, HakanPotential use of organic liquid mixtures consisting of amines, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU), 2-tert-butyl-1,1,3,3-tetramethylguanidine (BTMG), and linear alcohols (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol) in the capture of carbonyl sulfide is comprehensively and systematically investigated by density functional theory calculations at the omega B97X-D3/6-311+ +G(d,p) level of theory. In total, eighteen different systems as a combination of amines and alcohols are taken into account. A modified single-step, termolecular reaction mechanism among amine, alcohol, and carbonyl sulfide is considered. The findings from structural, thermodynamic, and kinetic analyses indicated that suggested reaction mechanisms for the eighteen different systems being studied are thermodynamically feasible, and the organic liquid mixture of BTMG with methanol yields the lowest energy barrier and the highest reaction rate constant in the capture of carbonyl sulfide.Article A Theoretical Investigation of 4,7-Di(furan Donor–acceptor Type Conjugated Polymer(Computational and Theoretical Chemistry, 2014) Kayi, Hakan; Elkamel, AliQuantum chemical calculations are performed using density functional theory (DFT) to investigate the HOMO–LUMO energy gap of the 4,7-di(furan-2-yl)benzo[c][1,2,5]selenadiazole-based (FSeF) donor– acceptor type conjugated polymer which ascertains the optoelectronic properties and plays a crucial role, especially in polymeric solar cell applications. In this paper, the most stable conformers of the FSeF monomer and its corresponding oligomers are investigated at the B3LYP/Def2TZV and B3LYP/LANL2DZ levels of theory, and their molecular structures are revealed. The band gap of the polymer is determined by linear-fitting and extrapolation of the DFT data. This gap is found to be 1.44 eV and 1.45 eV by the B3LYP/Def2TZV, and B3LYP/LANL2DZ with PCM calculations, respectively. Our theoretical findings related to the band gap of the FSeF polymer (PFSeF) are in good agreement with other experimental stud ies in the literature and, hence, the theoretical methods used in this study are promising for the design of similar donor–acceptor type novel conjugated polymers.Article Citation - WoS: 7Citation - Scopus: 9Innovative Carbon Dioxide-Capturing Organic Solvent: Reaction Mechanism and Kinetics(Wiley-v C H verlag Gmbh, 2017) Orhan, Ozge Yuksel; Tankal, Hilal; Kayi, Hakan; Alper, ErdoganThe reaction rates of CO2 with an innovative CO2-capturing organic solvent (CO2COS), consisting of blends of 2-tert-butyl-1,1,3,3-tetramethylguanidine (BTMG) and 1-propanol, were obtained as function of BTMG concentration and temperature. A stopped-flow apparatus with conductivity detection was used. The reaction was modeled by means of a modified termolecular reaction mechanism which resulted in a second-order rate constant, and activation energies were calculated for a defined temperature range. Quantum chemical calculations at the B3LYP/6-31G(d) level also produced the activation energy of this reaction system which strongly supports the experimental findings.
