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Öğe Ab initio moleküler orbital yöntemleri ile CO2(CO)8 izomerlerinin moleküler yapı parametrelerininve titreşim frekanslarının hesaplanması(Cumhuriyet Üniversitesi, 2013) Kariper, Sultan Erkan; Karakaş, DuranMetal karboniller ve türevleri çoğu organometalik bile?iklerin sentezinde ba?langıç maddesi ve çoğu tepkimelerde katalizör olarak kullanılır. Bu yüzden yapılarının belirlenmesi kimyada önemli bir yere sahiptir. ?nfrared spektroskopisi metal karbonillerin sterokimyasını belirlemek için sıkça kullanılır. Metal karboniller ve türevlerinin yapısı C-O bağ gerilme frekansları, band sayıları ve band ?iddetleri ile ili?kilidir. Ancak C-O bağ gerilme modlarının etiketlenmesi önemli bir problemdir. Hesaplamalı kimya bu sorunun çözümünde etkili bir yöntem olmu?tur.Bu çalı?mada, Co2(CO)8 kompleksinin C2v, D3d ve D2d simetrili izomerlerinin gaz faz, siklohekzan ve pentan çözücülerinde optimize geometrileri elde edildi. Optimize geometrilerde bağ uzunlukları ve bağ açıları belirlendi. Toplam enerjileri hesaplandı ve izomerlerin kararlığı tartı?ıldı. ?zomerlerin C-O bağ gerilme titre?im frekansları hesaplandı ve deneysel titre?im frekansları izomerlere etiketlendi. ?zomerlerdeki her bir atomun Mulliken yükleri hesaplandı. Üç izomer için elektronik spektrumlar elde edildi.Bu hesaplamalar sonucunda elde edilen bağ uzunlukları ve bağ açılarının deneysel değerler ile uyumlu olduğu bulundu. Toplam enerji değerlerine göre izomerlerin kararlılık sıralamasının C2v < D3d < D2d ?eklinde olduğu belirlendi. Hesaplan frekanslar, deneysel frekans uyumuna ve ?iddetlerine göre izomerlere etiketlendi. Mulliken populasyon analizine göre geri bağlanmanın C2v < D3d < D2d sırasına göre arttığı bulundu. Elde edilen elektronik spektrumların deneysel değerler ile uyum içinde olduğu görüldü. Ayrıca izomerlerin gaz faz ve çözücüde farklı spektrumlar verdiği bulundu.Anahtar kelimeler: Ab initio yöntemleri, Dikobalt oktakarbonil, Çok çekirdekli metal karboniller, Titre?im frekanslarıÖğe Alkin birimli piridil ligantları içeren bazı dinükleer metal karbonillerin kuantum kimyasal hesaplama yöntemleriyle yapısal, spektroskopik ve optik özelliklerinin incelenmesi(Cumhuriyet Üniversitesi, 2016) Kariper, Sultan Erkan; Karakaş, DuranGeçiş metal karbonil kompleksleri, lüminesans ve elektron transfer tepkimelerinde ilgi çekmeleri nedeniyle yaygın bir şekilde çalışılır. Metal karbonil kompleksleri katalitik işlemlerde katalizörler olarak ve tıbbi uygulamalarda koenzim, antioksidan ve antikanser ajanlar olarak kullanılır. Metal karbonil komplekslerinin katalitik, antioksidan ve antikanser aktiviteleri moleküler yapılarına bağlıdır. Bu nedenle, metal karbonilllerin yapılarının belirlenmesi kimyada önemli bir rol oynar. Alkin birimleri çoğu dönüşümlere ve ilginç özelliklere sahip olması nedeniyle çok yönlü fonksiyonel gruplardır. Alkin birimleri ve ligandların varlığıyla aynı molekülde iki ya da daha fazla metal merkezler bir arada tutulabilir. Alkin birimli piridil köprü ligandlar dinükleer komplekslerin oluşturulmasında yaygın olarak kullanılır. Bu kompleksler uzun ? konjugasyonuna sahip olmaları nedeniyle doğrusal olmayan optik materyal olarak hizmet verir. Orbital, optik ve yapısal özellikler modern hesaplamalı simülasyon metodları yardımıyla hesaplanabilir. Bu çalışmada, öncelikle gaz fazda HF, DFT(B3LYP) ve MPn (n=2,3) metodları ile LANL2DZ ve LANL2DZ/6-31G(d) temel setleri kullanılarak [(CO)4P(OPh)3W]2(m-DPB) ve [(CO)4P(OMe)3W]2(m-BPEB) komplekslerinin optimize geometrileri elde edildi. Hesaplanan ve deneysel veriler arasındaki korelasyona göre en uygun seviye B3LYP/LANL2DZ/6-31G(d) olarak belirlendi. [(CO)4LM]2(?-L') (M=W, Mo, Cr, L=CO, PMe3, P(OMe)3, PPh3 ve (P(OPh)3 L'=DPA, DPB, BPEB) için tüm hesaplamalar B3LYP/LANL2DZ/6-31G(d) seviyede yapıldı. Komplekslerin cis ve trans izomerlerinin toplam elektronik ve termal enerjileri, entalpileri ve toplam serbest enerjileri hesaplandı. Tüm kompleksler için yapısal parametreler öngörüldü. IR, NMR ve UV-VIS spektrumaları ile optimize yapıların uygunluğu desteklendi. Komplekslerin literatürde mevcut olmayan bağ gerilme frekansları, 1H-NMR kimyasal kayma değerleri ve UV-VIS spektrumları elde edildi. Tüm komplekslerin polarizibilite (?), anizotropik polarizibilite (??) ve birincil hiperpolarizibilite (?0) değerleri doğrusal olmayan optik özellikler için hesaplandı. Optimize yapılardan en yüksek dolu moleküler orbital enerjisi (EHOMO), en düşük boş moleküler orbital enerjisi (ELUMO), LUMO-HOMO enerji boşluğu (?E), mutlak sertlik (?), mutlak yumuşaklık (?), elektronegativite (?), kimyasal potansiyel (?), elektrofilisite indeksi (?), nükleofilisite indeksi (?) ve dipol moment (DM) hesaplandı. Sonuç olarak, [(CO)4P(OPh)3W]2(?-DPB) ve [(CO)4P(OMe)3W]2(?-BPEB) kompleksleri için hesaplanan bağ uzunlukları ve bağ açıları deneysel değerler ile uyumludur. Termodinamik parametrelere göre, cis izomerlerin trans izomerlerden daha kararlı olduğu bulundu. Hesaplanan bağ gerilme frekansları, 1H-NMR kimyasal kayma değerleri ve UV-VIS spektrumları deneysel verilerle uyumu dikkate alınarak [(CO)4LW]2(m-DPB) [L=CO, PPh3, P(OPh)3] ve [(CO)4LW]2(m-BPEB) [L=CO, PMe3, P(OMe)3, PPh3, P(OPh)3] komplekslerine etiketlendi. Hesaplamalardan elde edilen polarizibilite (?), anizotropik polarizibilite (??) ve birincil hiperpolarizibilite (?0) değerlerine göre tüm kompleksler optik materyal olarak kullanılabileceği öngörüldü. Ek olarak, komplekslerin NLO özellikleri en yüksek dolu moleküler orbital enerjisi (EHOMO), en düşük boş moleküler orbital enerjisi (ELUMO), LUMO-HOMO enerji boşluğu (?E), mutlak sertlik (?), mutlak yumuşaklık (?), elektronegativite (?), kimyasal potansiyel (?), elektrofilisite indeksi (?), nükleofilisite indeksi (?) ve dipol moment (DM) ile ilişkilendirildi.Öğe Computational study of some fluoroquinolones: Structural, spectral and docking investigations(ELSEVIER SCIENCE BV, 2018) Sayin, Koray; Karakas, Duran; Kariper, Sultan Erkan; Sayin, Tuba AlagozQuantum chemical calculations are performed over norfioxacin, tosufloxacin and levofloxacin. The most stable structures for each molecule are determined by thermodynamic parameters. Then the best level for calculations is determined by benchmark analysis. M062X/6-31 + G(d) level is used in calculations. IR, UV-VIS and NMR spectrum are calculated and examined in detail. Some quantum chemical parameters are calculated and the tendency of activity is recommended. Additionally, molecular docking calculations are performed between related compounds and a protein (ID: 2J9N). (C) 2017 Elsevier B.V. All rights reserved.Öğe Investigations of structural, spectral, electronic and biological properties of N-heterocyclic carbene Ag(I) and Pd(II) complexes(ELSEVIER SCIENCE BV, 2019) Sayin, Koray; Kariper, Sultan Erkan; Tastan, Merve; Sayin, Tuba Alagoz; Karakas, DuranComputational analyses of two Ag(I) and two Pd(II) complexes were done. Benchmark analyses were performed to obtain the most appropriate calculation level for studied complexes. HF, B3LYP and M062 x method were selected as calculation method. As for the basis set, lan12dz, 6-31G, 6-31G(d) and 6-31G(d,p) were selected. LANL2DZ was used for metal atoms and the others were for the rest atoms in related molecules. The most appropriate calculation level was determined as B3LYP/ 6-31G(d)(LANL2DZ). Structural and spectral analyses (IR, UV-VIS and NMR) were performed. Additionally, non-linear optical (NLO) properties and biological properties were investigated and examined in detail. According to calculation results, complex (4) was found as the best candidate for NLO applications. Additionally, complex (4) was found as the best candidate for lung cancer drug. (C) 2018 Elsevier B.V. All rights reserved.Öğe Multi-properties of a new azo-Schiff base and its binuclear copper(II) chelate: Preparation, spectral characterization, electrochemical, potentiometric and modeling studies(ELSEVIER SCIENCE BV, 2017) Sarigul, Munire; Kariper, Sultan Erkan; Deveci, Pervin; Atabey, Hasan; Karakas, Duran; Kurtoglu, MukerremIn this study, chromophore group containing a new Schiff base ligand 2-{(E)-[(3-hydroxy-4-methoxyphenyl)imino]methy1}-4-[(E)-phenyldiazenyl]phenol H(2)L3/2H(2)O, formed by the 1:1 M condensation of 5-amino-2-methoxyphenol with 2-hydroxy-5-[(E)-phenyldiazenyl]benzaldehyde and the binuclear copper(II) chelate of this ligand have been prepared. The structures of the ligand and its Cu(II) chelate have been elucidated on the basis of elemental analyses, conductivity measurements, spectral (FT-IR, H-1 and C-13 NMR and UV.-Vis.), electrochemical studies and theoretical calculations. Cu(II) ion coordinates with the ligand through the oxygen of the phenolic and nitrogen of azomethine group. The redox behaviors of the ligand and its binuclear Cu(II) chelate were investigated in DMSO solution containing 0.1 M tetrabutylammoniumtetrafluoroborate (TBATFB) as supporting electrolyte by cyclic voltammetry (CV). Five dissociation constants were determined for the prepared azo-Schiff base ligand as 3.25 (PKa1), 5.51 (pK(a2)), 7.18 (pK(a3)), 9.60 (pK(a4)) and 11.10 (pK(a5)). Also, the stability constants of the Cu(II) chelate have been calculated by SUPERQUAD computer program and general mechanisms have been proposed with regard to the formation of the complex. (C) 2017 Elsevier B.V. All rights reserved.Öğe The new O, O and N, O type ligands and their Cu(II) and Ni(II) complexes: Crystal structure, absorption-emission properties and superoxide dismutase mimetic studies(ELSEVIER SCIENCE SA, 2017) Kose, Reyhane; Gungor, Seyit Ali; Kariper, Sultan Erkan; Kose, Muhammet; Kurtoglu, MukerremIn this study, two new O, O type azo-aldehydes (HL1 and HL2), their N, O type salicylaldoxime derivatives containing azo chromophore group (HL3 and HL4) and Cu(II) and Ni(II) complexes were synthesized and characterized by elemental analysis, H-1-C-13 NMR, FT-IR, mass spectroscopies. Solid state structures of the HL3 and HL4 were also determined by single crystal X-ray diffraction method. Absorption and photoluminescence behaviours of the ligands and their metal complexes were investigated in DMF solution. Superoxide dismutase (SOD) activity of the Cu(II) and Ni(II) complexes were compared with the literature values. The K-cat values for SOD activity show that the complexes possess significant catalytic activity for the dismutation of superoxide compared to the data of some complexes and natural SOD enzymes given in the literature. The K-cat values for SOD activities of the complexes were found to be lower than natural enzymes. The complex [Cu(L-3)(2)] is the SOD mimic amongst the tested complexes with K-cat of 1.4 x 10(7) M-1 s(-1). (C) 2017 Elsevier B.V. All rights reserved.Öğe Pamoic acid esters and their xanthene derivatives: Flourimetric detection of nitroaromatic compounds and non-linear optical properties(ELSEVIER SCIENCE SA, 2018) Gungor, Seyit Ali; Sahin, Irfan; Gungor, Ozge; Kariper, Sultan Erkan; Tumer, Ferhan; Kose, MuhammetIn this study, four pamoic acid esters and a dibenzoxanthene derivative of pamoic acid ester were prepared and characterized by the analytical and spectroscopic methods Molecular structure of the synthesized compounds were determined by single crystal X-ray diffraction studies. Absorpsion and emission behaviours of the compounds were investigated in detail. Fluorescent detection of nitro aromatic compounds [nitro benzen (NB), 4-nitrophenol (4-NP) and 2,4-dinitrophenol(2,4-DNP)] by the synthesized compounds was examined. Sensing cabability to NACs, fluorescent titration experiments were performed and compound (2) exhibit the highest sensitivity against NB with a quenching constant (Ksv) of 1.03 x 10(7) M-1. Finally, non-linear optic properties of the compounds was investiagated by computational (C) 2017 Elsevier B.V. All rights reserved.Öğe Spectroscopic investigation, FMOs and NLO analyses of Zn(II) and Ni(II) phenanthroline complexes: A DFT approach(PERGAMON-ELSEVIER SCIENCE LTD, 2015) Sayin, Koray; Karaka, Duran; Karakus, Nihat; Sayin, Tuba Alagoz; Zaim, Zinet; Kariper, Sultan ErkanComputational studies were carried out on three Zn(II) and three Ni(II) complexes, namely [NiL1(phen)(2)], [ZnL1(phen)(2)], [NiL2(phen)(2)], [ZnL2(phen)(2)], [NiL3(phen)(2)] and [ZnL3(phen)(2)]. These complexes were synthesized in 2014 by Raman and Mahalalcshmi. Optimized structures of the studied complexes were calculated. IR and UV Vis spectra were calculated and examined in detail. Additionally, non-linear optical (NLO) properties and natural electron configurations of the metal atoms were investigated 'using some quantum chemical parameters and natural bond orbital (NBO) analysis. (C) 2015 Elsevier Ltd. All rights reserved.Öğe Theoretical investigation on the vibrational and electronic spectra of three isomeric forms of dicobalt octacarbonyl(ELSEVIER SCIENCE BV, 2014) Karakas, Duran; Kariper, Sultan ErkanThree isomeric forms of dicobalt octacarbonyl, [Co-2(CO)(8)], with C-2v, D-3d and D-2d point group were optimized by using density functional theory (DFT/B3LYP) method with LANL2DZ basis set for the cobalt atoms and 6-31G(d) basis set for the other atoms in the gas phase. Electronic structures, carbonyl stretching frequencies and Mulliken population analysis were determined from the optimized structures. Electronic structures indicate that each of the dicobalt octacarbonyl isomers have been constituted from two trigonal bipyramidal geometry. While the isomer C-2v has two bridged carbonyl groups, in the isomers D-3d and D-2d all carbonyl groups are coordinating as terminal. The calculated C-O stretching frequencies are in a good agreement with experimental frequencies. Experimental C-O stretching frequencies were assigned to isomers according to the calculated frequencies. Mulliken population analysis show that free carbonyl ligands transfer their electron to the cobalt atoms during formation of the complexes. The electronic spectra of isomers were obtained by using time dependent density functional theory (TD-DFT/B3LYP) method with LANL2DZ basis set for the cobalt atoms and 6-31G(d) basis set for the other atoms in the gas phase. The theoretical electronic spectra of isomers are in a good agreement with experimental spectra. The calculated bands at 277.9, 278.1 and 284.1 nm for isomers C-2v, D-2d and D-3d were assigned to metal-ligand charge transfer transitions and the shoulder at 344.6 nm was assigned to pure metal center transitions for isomer D-3d. (C) 2014 Elsevier B.V. All rights reserved.Öğe Theoretical spectroscopic study of seven zinc(II) complex with macrocyclic Schiff-base ligand(PERGAMON-ELSEVIER SCIENCE LTD, 2014) Sayin, Koray; Kariper, Sultan Erkan; Sayin, Tuba Alagoz; Karakas, DuranSeven zinc complexes, which are [ZnL1](2+), [ZnL2](2+), [ZnL3](2+), [ZnL4](2+), [ZnL5](2+), [ZnL6](2+) and [ZnL7](2+), are studied as theoretically. Structural parameters, vibration frequencies, electronic absorption spectra and H-1 and C-13 NMR spectra are obtained for Zn(II) complexes of macrocyclic penta and heptaaza Schiff-base ligand. Vibration spectra of Zn(II) complexes are studied by using Density Functional Theory (DFT) calculations at the B3LYP/LANL2DZ. The UV-VIS and NMR spectra of the zinc complexes are obtained by using Time Dependent-Density Functional Theory (TD-DFT) method and Giao method, respectively. The agreements are found between experimental data of [ZnL5](2+), [ZnL6](2+) and [ZnL7](2+) complex ions and their calculated results. The geometries of complexes are found as distorted pentagonal planar for [ZnL1](2+), [ZnL2](2+) and [ZnL3](2+) complex ions, distorted tetrahedral for [ZnL4](2+) complex ion and distorted pentagonal bipyramidal for [ZnL5](2+), [ZnL6](2+) and [ZnL7](2+) complex ions. Ranking of biological activity is determined by using quantum chemical parameters and this ranking is found as: [ZnL7](2+) > [ZnL6](2+) > [ZnL5](2+) [ZnL3](2+) > [ZnL2](2+) > [ZnL1](2+). (C) 2014 Elsevier B.V. All rights reserved.Öğe Theoretical Studies on Eight Oxovanadium(IV) Complexes with Salicylaldehyde and Aniline Ligands(2014) Kariper, Sultan Erkan; Sayın, Koray; Karakaş, DuranEight oxovanadium(IV) complexes with five-coordinate consists of salicylaldehyde and anilines which their abbreviated representations are $VO(sal-anl)_2$ (1), VO(sal-clanl)2 (2), $VO(sal-mxyanl)_2$ (3), $VO(sal-ntranl)_2$ (4), $VO(brsal-anl)_2$ (5), $VO(brsal-clanl)_2$ (6), $VO(brsal-mxyanl)_2$ (7), $VO(brsal-ntranl)_2$ (8) were optimized by using density functional theory (DFT) at B3LYP level with 6-31G and LANL2DZ basis sets in vacuum. Geometrical parameters, stretching frequencies and some quantum chemical parameters of all complexes were obtained from optimized structures. Bond distance and bond angle are not present in the literature were predicted with computational methods. The calculated V-O stretching frequencies of complexes were calculated at B3LYP method with 6-31G and LANL2DZ basis sets. The most compatible stretching frequencies with the experimental values were found with B3LYP/6-31G level. Some quantum chemical parameters were calculated to predict the biological activity ranking. Biological activity ranking of these complexes were found as (7) < (8) < (4) < (6) < (5) < (2) < (1) < (3)Öğe Theoretical study on the antitumor properties of Ru(II) complexes containing 2-pyridyl, 2-pyridine-4-carboxylic acid ligands(ELSEVIER SCIENCE BV, 2017) Kariper, Sultan Erkan; Sayin, Koray; Karakas, Duran[Ru(bipy)(2)(CppH)](2+) (1), [Ru(bipy)(2)(Cpp-NH-Hex-COOH)](2+) (2), [Ru(dppz)(2)(CppH)](2+) (3) and [Ru(dppz)(2)(Cpp-NH-Hex-COOH)](2+) (4) were calculated by Hartree-Fock (HF), Density Functional Theory (DFT) hybrid B3LYP and Moller-Plesset Perturbation (MPn n = 2,3) theory method and CEP-4G, CEP-31G, CEP-121G, LANL2DZ, LANL2MB, SDD basic sets and a mixed basic set with the keyword GEN in gas phase and water. Structure parameters obtained from optimized structures were compared with experimental parameters. M062X/(6-31G(d))(CEP-4G) level was taken into account for the most appropriate calculation level. IR, UV VIS and NMR spectrums were examined for structural characterization. The optimal structure was identified via structure parameters, IR, UV VIS and NMR spectrums. For the most compatible structure, the highest molecular orbital energy (E-HOMO) which one of the most effective chemical determiners on the antitumor activity of the complexes, the lowest molecular orbital energy (E-LUMO), LUMO-HOMO energy gap, hardness (eta), softness (sigma), electronegativity (chi), chemical potential (mu), electrophilicity index (omega), molar volume (V), dipole moment (DM), total negative charge (TNC), enthalpy (H), entropy (S) and total energy (E) were calculated. The causes of anticancer activity of the complexes have been studied. (C) 2017 Elsevier B.V. All rights reserved.
