02. Fen Fakültesi / Faculty of Science

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Citation - WoS: 3
Citation - Scopus: 4
1,2-Diboranes With Strong Donor Substitutes: Synthesis, Ovicidal and Larvicidal Effect on Important Vector Species
(Elsevier, 2024) Bursali, Fatma; Özgener, Hüseyin; Sahin, Yueksel; Aygun, Muhittin; Sevincek, Resul; Biyik, H. Halil; Özgener, Hüseyin; Gurbuz, Burcin; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Novel control products are needed in the control of important insects like mosquitoes which are developing resistance to insecticides and larvicides currently in the market. Boron compounds have been demonstrated to exhibit antibacterial and anticancer effects. 1,2-diboranes with a long history and importance in boron chemistry have been described. These compounds are synthesized from reactions of 1,2-dichlordiborane derivatives with lidium amides (ArNHLi/Et2NLi, etc.). In addition to the three previously synthesized diborane compounds, five novel 1,2-diborane compounds were synthesized in good yield using the same method for the first time. The structures of the novel derivatives were characterized by nuclear magnetic resonance spectroscopy, and the molecular structure of one of them (2a) was also demonstrated using single crystal X-ray diffraction. In this preliminary study, the ovicidal and larvicidal effects of new 1,2-diamino-1,2-diborane derivatives against Aedes aegypti and Aedes albopictus eggs and larvae were investigated for the first time. Of these, 2a and 2e showed the highest ovicidal activity against both species, while 7, 4 and 2d showed particularly high larvicidal activity. Some 1,2-diborane derivatives were found to be significantly toxic, with LC50 values ranging from 14,930 to 27,975 mu g/mL. Some derivatives (6, 2a, 2c) were less effective against mosquito larvae. 1,2-Diborane derivatives have high ovicidal and larvicidal effects on mosquitoes and are therefore potential candidates for the development of new larvicides. Further studies are needed to evaluate its mode of action and safety. Understanding their mode of action against mosquito development is crucial to optimizing their use and reducing the potential development of resistance. Their potential effects on other mosquito species and non -target organisms need to be investigated.
Citation - WoS: 6
Citation - Scopus: 7
1,2-Diborolanes With Strong Donor Substituents: Synthesis and High Antimicrobial Activity
(Academic Press, 2021) Şahin, Yüksel; Özgener, Hüseyin; Poyrazoğlu Çoban, Esin; Sevinçek, Resul; Bıyık, Halil H.; Özgener, Hüseyin; Aygün, Muhittin; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
1,2-diborolanes with strong and without strong donor substituents have been described, and are also referred to as 1,2-diboracyclopentane. The 1,2-diaryl/alkyl-amino-1,2-diboracyclopentanes 2, 3, and 4 were obtained in good yield after the reaction of 1,2-dichloro-1,2-diboracyclopentane 1 with ArNHLi and Me3Si-NR2. The structures of these new derivatives were characterized by nuclear magnetic resonance spectroscopy. The molecular structures of 2b, 2c, 2e, 4, and 5f were also determined by single-crystal X-ray diffraction. The newly synthesized 1,2-borolanes are stable in air and showed particularly high activity against some Gram-positive bacteria. © 2020 Elsevier Inc.
Citation - WoS: 2
Citation - Scopus: 3
1-Octanol Is a Functional Impurity Modifying Particle Size and Photophysical Properties of Colloidal Zncdsse/Zns Nanocrystals
(American Chemical Society, 2021) Sevim Ünlütürk, Seçil; Özçelik, Serdar; Çağır, Ali; Varlıklı, Canan; Varlıklı, Canan; Çağır, Ali; Özçelik, Serdar; 04.01. Department of Chemistry; 04.04. Department of Photonics; 04. Faculty of Science; 01. Izmir Institute of Technology
Impurities in trioctylphophine (TOP) strongly affect nanocrystal synthesis. 1-Octanol among other contaminants in TOP is identified for the first time as a functional impurity by H-1 NMR. The deliberate addition of 1-octanol into trioctylphosphine reduced particle size and modified photophysical properties of ZnCdSSe/ZnS colloidal nanocrystals. NMR analysis furthermore revealed that 1-octanol is bonded to the nanocrystal surfaces. The ratio of integrals for the O-CH2 protons of 1-octanol, which is the lowest compared to the other ligands, suggests that 1-octanol plays a critical role to tune the particle size of nanocrystals. The increased amount of 1-octanol added into TOP reduces the particle size from 9.8 to 7.2 nm, causing a progressive blue shift in the UV-vis and PL spectra but leaving the alloy composition unaffected. The rate of nonradiative processes is enhanced with the amount of 1-octanol added into TOP, correlating with higher dislocation density observed in the nanocrystals. As a conclusion, 1-octanol is proposed as a functional impurity that varies particle size and nonradiative photophysical processes in the ZnCdSSe/ZnS colloidal nanocrystals.
2’-Methylklavuzon Causes Lipid-Lowering Effects on A549 Non-Small Cell Lung Cancer Cells and Significant Changes on Dna Structure Evidenced by Fourier Transform Infrared Spectroscopy
(Elsevier, 2020) Ceylan, Çağatay; Çağır, Ali; Aksoy, Hatice Nurdan; Ceylan, Çağatay; Çağır, Ali; Çetinkaya, Hakkı; 03.08. Department of Food Engineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
Various chemical agents are used in the treatment of Non-Small Cell Lung Cancer (NSCLC). 2?-methylklavuzon was proposed as a potential chemotherapeutic agent in cancer treatment based on its topoisomerase inhibition activity. In this study the cellular effects of 2?-methylklavuzon was evaluated on A549 cancer cells using FTIR spectroscopy. 2?-methylklavuzon induced significant changes on both the whole cell lyophilizates and the lipid extracts of the A549 lung cancer cells. 2?-methylklavuzon caused significant structural changes in A549 cell DNA structure: T, A and G DNA breathing modes are lost after the drug application indicating the loss of topoisomerase activity. The level of transcription and RNA synthesis was enhanced. 2?-methylklavuzon induced single stranded DNA formation evidenced by the increase in the ratio of asymmetric/symmetric phosphate stretching modes. 2?-methylklavuzon induced band shifts only in the asymmetric mode of phosphate bonds not in the symmetrical phosphate bond stretching. 2?-methylklavuzon induced A form of DNA topography. In addition to the changes in the DNA structure and transcription 2?-methylklavuzon also caused lipid-lowering effect in A549 cancer cells. 2?-methylklavuzon suppressed lipid unsaturation, however, it induced formation of lipids with ring structures. 2?-methylklavuzon suppressed phosphate-containing lipids significantly and decreased carbonyl containing lipids and cholesterol slightly. 2?-methylklavuzon caused increases in the hydrocarbon chain length. Overall, 2?-methylklavuzon can be used as a lipid-lowering compound in the treatment of NSCLC and other cancer therapies. © 2020 Elsevier B.V.
Citation - WoS: 17
Citation - Scopus: 16
2-D Analysis of Ge Implanted Sio2 Surfaces by Laser-Induced Breakdown Spectroscopy
(Elsevier Ltd., 2008-10) Yalçın, Şerife; Yalçın, Şerife; Örer, Sabiha; Turan, Raşit; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
2-D elemental distribution of Ge in silicon oxide substrates with differing implantation doses of between 3 × 1016 cm- 2 and 1.5 × 1017 cm- 2 has been investigated by Laser-Induced Breakdown Spectroscopy (LIBS). Spectral emission intensity has been optimized with respect to time, crater size, ablation depth and laser energy. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) coupled with Energy-Dispersive X-Ray Spectroscopy (EDX) have been utilized to obtain crater depth, morphology and elemental composition of the sample material, respectively. LIBS spectral data revealed the possibility of performing 2-D distribution analysis of Ge atoms in silicon oxide substrate. EDX analysis results confirmed that LIBS is capable to detect Ge atoms at concentrations lower than 0.2% (atomic). LIBS as a fast semi-quantitative analysis method with 50 μm lateral and 800 nm depth resolution has been evaluated. Results illustrate the potential use of LIBS for rapid, on-line assessment of the quality of advanced technology materials during the manufacturing process. © 2008 Elsevier B.V. All rights reserved.
5-Sübstitüentli alpha,beta -doymamış laktonların sentezlenmesi ve biyolojik aktivitelerinin incelenmesi
(2009) Çağır, Ali; Kasaplar, Pınar; Akçok, İsmail; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
5,6-dihidro-2H-pyran-2-on yapısını içeren birçok doğal ürünün çeşitli biyolojik aktivitelere sahip olduğu bilinmektedir. Bunların en ilginçlerinden olan goniothalamin sağlıklı hücreler üzerinde minimal etkiye sahipken kanserli hücrelerde sitotoksik etkisi olduğu bilinmektedir. Bu çalışmada goniothalaminin stiril sübstitüentinin 2-naftil grubuyla yerdeğiştirilmesiyle oluşacak konformasyonel olarak sınırlandırılmış molekülün (R)- ve (S)- enansiyomerleri 2-naftil aldehitten başlanarak literaturde bilinen yöntemlerle asimetrik olarak sentezlenmiş, PC-3, MCF-7, DU-145 ve LNCAP kanser hücreleri üzerinde test edilmiştir. Bulgular konformasyonel olarak sınırlandırılmış R enansiyomerinin aktivite üzerinde küçük bir artış gösterdiği yönündedir. 2-Naftil grubu sitiril grubuna göre daha büyük bir grup olduğundan siterik faktörlerin aktivite üzerindeki etkilerinin incelenmeside gerekli görülmüştür.
Citation - WoS: 31
Citation - Scopus: 34
6-Bicycloaryl Substituted (s)- and (r)-5,6 Asymmetric Synthesis, and Anti-Proliferative Properties
(Elsevier Ltd., 2009-01) Kasaplar, Pınar; Çağır, Ali; Yılmazer, Özgür; Çağır, Ali; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
(R)-Goniothalamin, is a member of styryl lactones, possesses selective cytotoxicity against cancer cell lines. In this work, replacement of styryl substituent with 2-naphthyl and 3-quinoyl gave new analogues which may have less conformational changes compared to the lead compound. Anti-proliferative tests indicated that 2-naphthyl substituted (R)-5,6-dihydro-2H-pyran-2-one has slightly better cytotoxicity than (R)-goniothalamin. To clarify the effect of 2-naphthyl substituent additional aryl substituted (R)-5,6-dihydro-2H-pyran-2-ones have been synthesized enantioselectively and tested against PC-3 and MCF-7 cell lines.
Citation - WoS: 43
Citation - Scopus: 46
Aas, Xrpd, Sem/Eds, and Ftir Characterization of Zn2+ Retention by Calcite, Calcite–kaolinite, and Calcite–clinoptilolite Minerals
(Elsevier Ltd., 2005-04-08) Shahwan, Talal; Eroğlu, Ahmet Emin; Zünbül, Banu; Shahwan, Talal; Tunusoğlu, Özge; Eroğlu, Ahmet Emin; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
In this study, the sorption behavior of Zn2+ on calcite, kaolinite, and clinoptilolite, in addition to mixtures of calcite with kaolinite and clinoptilolite, was investigated at various loadings and mixture compositions using atomic absorption spectroscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy, X-ray powder diffraction, and Fourier transform infrared techniques. According to the obtained results, within the experimental operating conditions, the sorption capacity was enhanced with increasing amount of calcite in both types of mixtures. Under neutral–alkaline pH conditions and high loadings, the order of Zn2+ retention was observed as calcite > clinoptilolite > kaolinite. The experiments on the retention of Zn2+ by pure calcite under conditions of oversaturation showed that the uptake process proceeds via an initial adsorption mechanism (possibly ion-exchange type) followed by a slower mechanism that leads to the overgrowth of the hydrozincite phase, Zn5(OH)6(CO3)2.
Citation - WoS: 4
Citation - Scopus: 6
Absorption Spectrum of Monomeric Pseudoisocyanine: a New Perspective and Its Implications for Formation and Spectral Response of J-Aggregates in Solution and in Thin Films
(Elsevier Ltd., 2008-05) Gülen, Demet; Özçelik, Serdar; Özçelik, Serdar; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
We argued against the current spectral assignment for absorption spectrum of monomeric PIC which is widely accepted since the pioneering works of Scheibe and Jelley [G. Scheibe, Angew. Chem. 49 (1936) 563; E.E. Jelly, Nature 138 (1936) 1009]. A new spectrum is presented along with its conceptual basis. The hypothesized spectrum attributes the previous 0-0 (≈525 nm) and 0-1 (≈490 nm) assignments, respectively, to intermediates acting as the precursor of J-aggregates and to the 0-0 transition of monomeric PIC and brings the spectrum in accord with the seemingly universal spectral fingerprint of cyanines. The hypothesis is used to analyze and interpret the temperature dependence of the UV-vis absorption of PIC aggregates in saline aqueous solution by incorporating the J-band simulations within frenkel exciton formalism. Its implications for aggregate formation kinetics are given on the basis of current spectroscopic evidence. The hypothesis readily answers several long-standing questions: Why compared to many other cyanines at least an order of magnitude higher dye concentration is needed to form J-aggregates of PIC? Why are there no precursors, since aggregation is expected to be a consecutive process? A large number of observations on steady-state and time-resolved spectral properties, and aggregation kinetics in solution/thin films are likely to find reasonable explanations within this hypothesis.
Citation - WoS: 7
Citation - Scopus: 8
Acylation of 2-Methoxynaphthalene Over Ion-Exchanged Ss-Zeolite
(Elsevier Ltd., 2002) Kantarlı, İsmail Cem; Yılmaz, Selahattin; Artok, Levent; Ülkü, Semra; Bulut, Hatice; Artok, Levent; Yılmaz, Selahattin; Ülkü, Semra; 03.02. Department of Chemical Engineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
Friedel-Crafts acylation of 2-Methoxynaphthalene was carried out over various ion-exchanged β zeolites (Mn+β, where Mn+: In3+, Zn2+, Al3+, Fe3+, La3+) with various anhydride (acetic, propionic and benzoic anhydrides), or acyl chloride (acetyl, propionyl and benzoyl chlorides) acylating reagents. The results suggested that selectivity towards the 6-substituted products was higher with the larger size anhydrides, propionic and benzoic anhydrides. The metal cation type within the zeolite significantly influenced the extent of conversion and product distribution. That La3+ exchanged zeolite displayed higher selectivity for the 6-position acylated product with anhydrides ascribed mainly to narrowing of channels by the presence of La(OH)2+ ions that leave no room for the formation of more bulky isomeric forms and to enhanced Bronsted acidity of the zeolite. With acyl chlorides, the recovery of ketone products was found to be remarkably low. 1-Acyl-2-methoxynaphthalenes actively underwent deacylation when acyl chlorides were used as the acylation reagent.
Citation - WoS: 21
Citation - Scopus: 23
Adsorption of Methylene Blue From Aqueous Solution on High Lime Fly Ash: Kinetic, Equilibrium, and Thermodynamic Studies
(Taylor and Francis Ltd., 2012-01) Keleşoğlu, Serkan; Polat, Hürriyet; Kes, Mürşide; Sütçü, Leman; Polat, Hürriyet; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Kinetic, equilibrium, and thermodynamic studies were performed for the batch adsorption of methylene blue (MB) on the high lime fly ash as a low cost adsorbent material. The studied operating variables were adsorbent amount, contact time, dye concentration, and temperature. The kinetic data were analyzed using the pseudo-first order and pseudo-second order kinetic models and the adsorption kinetic was followed well by the pseudo-second order kinetic model. The equilibrium data were fitted with the Freundlich, Langmuir, and Dubinin Radushkevich (D-R) isotherms and the equilibrium data were found to be well represented by the Freundlich and D-R isotherms. Based on these two isotherms MB is taken by chemical ion exchange and active sites on the high lime fly ash have different affinities to MB molecules. Various thermodynamic parameters such as enthalpy of adsorption (ΔH°), free energy change (ΔG°), and entropy change (ΔS°) were investigated. The positive value of ΔH° and negative value of ΔG° indicate that the adsorption is endothermic and spontaneous. The positive value of ΔS° shows the increased randomness at the solid-liquid interface during the adsorption. A single-stage batch adsorber was also designed based on the Freundlich isotherm for the removal of MB by the high lime fly ash. © 2012 Copyright Taylor and Francis Group, LLC.
Citation - WoS: 38
Citation - Scopus: 41
Adsorption of Peo/Ppo Triblock Co-Polymers and Wetting of Coal
(Elsevier Ltd., 1999-01) Polat, Hürriyet; Polat, Hürriyet; Chander, Subhash; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
The adsorption characteristics of PEO/PPO/PEO triblock co-polymers on coal were investigated using surface tension and contact angle measurements. Although these surfactants have been widely used as wetting agents, it was observed that they increased the hydrophobicity of coal at concentrations below about 10-6 M. Surface tension studies were carried out to explain the reasons for this behavior. The surface tension versus concentration profiles displayed three distinct regions. In region I, surface tension decreased linearly and monomers were proposed to be the dominant species. This region extended to a surfactant concentration of about 10-6 M. In region II, a transition region between regions I and III, dimers, trimers, etc., were considered to form. In region III, micelles formed and surface tension was independent of concentration. The concentration at which monomers associate to form dimers, etc., is referred to as the critical association concentration (cac). The contact angle of coal increased when concentration was raised from low values to the cac. It decreased when the reagent concentration was above the cac. Finally, at concentrations above the cmc, the wetting of coal was complete and contact angle was zero.
Citation - Scopus: 3
Advances and Future Perspective of Graphene Field Effect Transistors (gfets) for Medical Diagnostics and Point-Of Tools
(World Scientific Publishing, 2022) İnanç, Dilce; Karabacak, Soner; Mutlu, Mustafa Umut; İnanç, Dilce; Karabacak, Soner; Mutlu, Mustafa Umut; Yıldız, Ümit Hakan; Yıldız, Ümit Hakan; 04.04. Department of Photonics; 04.01. Department of Chemistry; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
Recently, major focus has been centered to enhance the capability of graphenebased devices and to facilitate utilization of graphene for biological applications by lowering its toxicity. In this chapter, from synthesis to applications, many of the conspicuous characteristics of graphene have been elaborately reviewed. We primarily focused on graphene-based field effect transistor (FET) for medical diagnostics and point-of-care applications. The device configurations and their application potential as well as sensing capability of various graphene FETs (GFETs) have been discussed. Here, we have also presented several aspects and advantages of GFETs in medical applications while discussing their pros and cons in commercialization. We address the advances and challenges for GFET-based sensing platforms for the medical applications and elaborate the combination strategy of GFETs with the existing commercial systems. © 2023 by World Scientific Publishing Co. Pte. Ltd.
Alkenil Oksiranların Organoborlar ile Paladyum Katalizli Tepkimeleri: 4-aril Ya Da 4-alkenil Sübstitüye Allil Alkollerin Sentezinde Regio ve Stereo Seçimli Bir Yöntem
(2016) Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Bu proje kapsamında laboratuvarda sentezlenen alkenil epoksitlerin organoborlar ile rodyum ve paladyum katalizli tepkimeleri gerçekleştirilmiştir. Paladyum katalizli tepkimeler yüksek regio-seçimlilikte gerçekleşerek başlıca 1,4 katılma ürünü olan arillenmiş ya da alkenillenmiş allil alkol (3) türevlerini oluşturmuştur. 1,2 Katılma ürünü olan homoallil alkol (4) türevleri ise genellikle düşük miktarlarda oluşan yan ürünlerdir. Her iki regio-izomer tipi kolon kromatografisi ile ayrılabilmektedir. Ayrıca tepkimeler yüksek stereo-seçimlilik göstermiştir. Genellikle ürünlerin diastereomerik oranı >20:1 olarak saptanmıştır. Epoksit uç karbonunun serbest ve korunmasız bir karbinol grubunun bulunmasının tepkime regio-seçimliliği için gerekli olduğu saptanmıştır. Ayrıca literatürde nadir olarak uygulama alanı olan trifenil arsin ligandının yöntemin regio ve stereo seçimliliğinde fosfin ligandlarına kıyasla çok daha etkin olduğu saptanmıştır. Bununla birlikte rodyum katalizörü ile de yüksek seçimlilikte arzu edilen ürün elde edilse de tepkime verimliliği yeterli bir mertebeye ulaşamamıştır.
Alkenilboron bileşiklerin rodyum katalizli C-H aktivasyon/karbonilasyon prosesleri ile indenon ve indanon yapılarının sentezi
(2012) Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Boron ya da halojenür gruba göre vicinal alkenyl karbonunda aril grubu içeren alkenilboron ya da alkenil halojenür bileşikleri CO ya da alkinler ile rodyum ve paladyum katalizli tepkimeleri gerçekleştirilmiştir. Alkenilmetal yapılarının arilboronların ve aril halojenürlerin geçiş metal katalizli annulasyon tepkimelerinde elzem ara yapılar olarak önerilmesi nedeniyle alkenil reaktiflerin alkenilmetal yapılarına dönüşmeleri, alkenilmetalların CO ya da alkin bileşiklerine katılması ve sonrasında C-H aktivasyonu ile annule ürünler vermesi beklenmektedir. Alkenilboronların rodyum katalizli tepkimleri annule ürünleri oluşturmuştur. Ancak bu oluşum ile birlikte deboronilasyon ve diğer yan ürünleri de meydana gelmiştir. Alkenil bromürler oksidatif paladyum katalizli tepkimelere reaktif davranmamıştır. Ancak bir alkenil iyodür oligomerik ürünler vermiştir. Bu çalışmanın bulguları önceki annulasyon tepkimelerinde alkenilmetal yapılarının rolünü vurgulayan yorumları sorgulamaktadır.
Altın katalizörlüğünde enantiyoseçici eklenme/halkalaşma tepkimeleri
(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2013) Emrullahoğlu, Mustafa; Cantürk, Ceren; Özalp, Ragıp; Kanbur, Tuğçe; 04.04. Department of Photonics; 01. Izmir Institute of Technology; 04. Faculty of Science
Bu projede, altın katalizörleri ile organokatalizörler kullanılarak benzopiran bileşiklerinin enantiyoseçici olarak sentezlenmesi tarif edilmiştir. Çalışmanın ilk aşamasında farklı alkil gruplarıyla türevlendirilmiş alkinil benzaldehit bileşikleri Sonogashira kenetlenme tepkimesi ile sentezlenmiştir. Elde edilen bileşikler farklı organokatalizörler varlığında karbonil bileşikleri ile reaksiyona girdirilip hem rasemat hem de enantiyo seçici olarak alkinil benzil alkollere dönüştürülmüştür. Çalışmanın bir sonraki aşamasında çeşitli altın katalizörleri kullanılarak halkalaştırma tepkimeleri gerçekleştirilmişitir. Optimizasyon çalışmaları sonucunda halkalaşma tepkimeleri için en uygun tepkime koşulu belirlenmiş ve bu koşul kullanılarak enantiyomerik olarak saf benzopiran bileşikleri elde edilmiştir. Yapılan her sentez sonunda elde edilen ürünler 1H NMR ve 13C NMR yöntemleriyle karakterize edilmiştir. Ayrıca rasemat ve enantiyo seçici olarak elde edilen ürünlerin enantiyomerik saflıklıkları HPLC ölçümleri ile saptanmıştır. Bunlara ek olarak enantiyoseçiciliği arttırmak amacıyla farklı organokatalizörler sentezlenmiştir. Enatiyoseçiciliği artırma çalışmalarının yanısıra katalizörlerin çözünürlük problemini ortadan kaldırmak amacıyla çeşitili yaklaşımlar ortaya konulmuştur. Projenin son aşamasında ise en uygun koşullarda eş zamanlı reaksiyon denemeleri yapılmış ve başarıyla sonuçlandırılmıştır.
Citation - WoS: 5
Citation - Scopus: 7
Alumina/Water Suspensions in the Presence of Peo-Ppo Triblock Copolymers
(Elsevier Ltd., 2004-09) Şakar Deliormanlı, Aylin; Polat, Hürriyet; Polat, Hürriyet; Çiftçioğlu, Muhsin; Çiftçioğlu, Muhsin; Şakar Deliormanlı, Aylin Müyesser; 03.02. Department of Chemical Engineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
The aim of this study was to investigate the stability and dispersion behaviour of aqueous alumina suspensions in the presence of polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) type triblock copolymers. For this purpose alumina suspensions at various solids loadings were prepared using four different methods. These are: Method I: powder and water were stirred only; Method II: powder and water were stirred and ultrasonic treatment was applied; Method III: powder and water were stirred in the presence of block copolymers; Method IV: powder and water were stirred and ultrasonic treatment was applied in the presence of block copolymers. These suspensions were characterized by means of rheological measurements. Sedimentation and turbidity measurements were also conducted to support these results and to investigate the stability of these systems for longer times. Surface tension measurements were performed to investigate the adsorption behaviour of block copolymers onto alumina surface. It was found that the use of PEO-PPO-PEO type triblock copolymers improved the dispersion behaviour of aqueous alumina suspensions in the presence of ultrasonic treatment at low solids loadings. However their effect was not significant at high solids loadings and without ultrasonic treatment.
Citation - WoS: 1
Citation - Scopus: 1
Amalgamation Performances of Gold-Coated Quartz Wool, Alumina, Silica, Sand and Carbon Fiber for the Determination of Inorganic Mercury in Waters by Cold Vapor Atomic Absorption Spectrometry
(Pleiades Publishing, 2017-05) Erdem Şimşek, Arzu; Shahwan, Talal; Erdem Yayayürük, Aslı; Eroğlu, Ahmet Emin; Shahwan, Talal; Eroğlu, Ahmet Emin; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Different gold-coated sorbents for amalgamation were applied for the determination of inorganic mercury in waters using a home-made cold vapor generation unit coupled to atomic absorption spectrometry. Among the gold-coated materials investigated (quartz wool, alumina, silica, sand and carbon fiber) quartz wool was found to give the most efficient results in terms of sorption and release. Analytical performance of the system without and with amalgamation was investigated and it was found that when amalgamation was applied, the linearity and slope of the calibration plots were independent on the sample volume for 1.0, 5.0 and 10.0 mL. Method validation was realized through the analysis of a sample of spring water spiked with 1.0 μg/L inorganic mercury and the spike recoveries were found to be 95 ± 1, 91 ± 3, and 99 ± 5% for 1.0, 5.0, and 10.0 mL, respectively. The results demonstrated that the methodology can be applied to these types of samples directly or after amalgamation, depending on the mercury concentration.
Citation - WoS: 2
Citation - Scopus: 3
The Amido and Bisalkoxo-Complexes of [tri(3,5-Dimethylpyrazolyl)borato]molydenum Nitrosyl
(TÜBİTAK, 1998) Topaloğlu, Işıl; Sözüer, Işıl; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
In this study, the amido nitrosyl molybdenum complex, [Mo{HM(3,5-Me2C3HN2)3}(NO)Cl(NH 2)], was prepared. This compound reacts with alocohols, yielding the bisalkoxo complexes, [Mo{HM(3,5-Me2C3HN2)3}(NO)(OR) 2] (R = Me, Et, Prn, Bun). The new complexes were analyzed by IR and 1H-NMR spectroscopy.
Citation - WoS: 9
Citation - Scopus: 11
Analysis of Dilution Induced Disintegration of Micellar Drug Carriers in the Presence of Inter and Intra Micellar Species
(Elsevier, 2020) Polat, Hürriyet; Polat, Hürriyet; Kutluay, Gülistan; Polat, Mehmet; Polat, Mehmet; 04.01. Department of Chemistry; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
Micelles of self-assembling polymeric surfactant molecules are promising nanoscopic carriers for lipophilic and toxic drugs, genes, and imaging molecules. Though it is a must for successful transport, ensuring micelle integrity is a challenge during intravenous injection where micelles must endure abrupt dilutional effects and encounters with native molecules. Therefore, direct observational evidence of how micelles behave during dilution is valuable in manipulating the designs of these carriers for a succesful drug delivery. Morphology and stability of the barren and a drug-loaded (lipophilic probucol) micelles of a polymeric surfactant (Pluronic® P123) were monitored during systematic re-dilution in distilled water and simulated body fluid in the presence of a model protein (bovine serum albumin). It was observed through surface tension, dynamic light scattering, laser velocimetry, transmission scanning and transmission electron microscopy, and atomic force microscopy analyses that the micelles disintegrated to various degrees in all cases upon dilution. The results indicate that dilution effects must be taken into account in designing micellar drug carriers. The assistance of some other means of protection such as encapsulation should be considered for ensuring micelle integrity within the bloodstream. © 2020 Elsevier B.V.

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