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  • Öge
    Modifiye edilmiş nanokompozit malzeme sentezi ve sulu ortamdan sezyumun uzaklaştırılmasında kullanımı
    (Lisansüstü Eğitim Enstitüsü, 2021) Çetin, Bilal ; Özcan, Mustafa ; Karakelle, Bektaş ; 724296 ; Kimya
    Radyoaktif atık, radyoaktif materyallerin sanayi ve tıp sektöründe kullanımının yanı sıra araştırma ve nükleer kuruluşlardan kaynaklanan kaçınılmaz sonuçtur. Bu nedenle, radyoaktif atıkların yönetimi ve bertarafı, neredeyse tüm ülkeleri ilgilendiren bir konudur. Ayrıca, nükleer bilim ve teknolojinin gelişimi, özellikle nükleer enerjinin geniş kullanımı, radyoaktivite kirliliği yoluyla insan çevresini ciddi şekilde tehdit etmektedir. Reaktördeki en önemli fisyon radyonüklitlerinden ikisi olan Cs-137 ve Cs-134, insan sağlığı ve çevre için potansiyel olarak tehlikeli olarak kabul edilir, çünkü sezyumun yüksek çözünürlüğü, uzun yarılanma süresi ve nükleer santrallerde yüksek verimliliğe sahip olması yeraltı sularından biyosfere doğru hareketine neden olmaktadır. Aslında nükleer silah denemeleri ve nükleer santrallerdeki kazalar neticesinde ortaya çıkan Cs-137 ve Cs-134 gibi radyonüklitler atmosfere dağılırlar sonrasında toprakta ve tarımsal ürünlerde kontaminasyona sebep olurlar. Topraktaki radyoaktif sezyumun bitkiler tarafından absorplanması bu bitkilerin hayvanlar tarafında tüketilmesiyle radyoaktif sezyum besin zincirine (et, süt, peynir, bitkisel gıdalar vb.) katılır ve insan bünyesine geçerek bir döngü oluşturur. Bu sebeple radyoaktif sezyumun uzaklaştırılması radyoaktif atık yönetimi açısından büyük önem arz etmektedir. Bu çalışmada kitosan (C56H103N9O39), K4[Fe(CN)6] ve Fe3O4 (Manyetit) ile nanokompozit malzeme sentezlenmiş, FTIR, BET, XRD, SEM ve TGA-DTA ile karakterize edilmiş ve sulu ortamdan sezyumun uzaklaştırılmasında adsorban olarak kullanılmıştır. Bu bağlamda, nanokompozit adsorban üzerine Cs+ adsorpsiyon davranışları pH, sıcaklık, adsorban miktarı, başlangıç sezyum konsantrasyonları, çalkalama hızı, temas süresinin bir fonksiyonu olarak çalışmalar gerçekleştirildi. Bu çalışmalara ilaveten nanokompozit üzerine sezyum adsorpsiyonunda yabancı iyon etkisi, nanakompozitten sezyumun desorpsiyonu, kolon çalışmaları ve radyoaktif sezyum çözeltileri kullanılarak nanokompozit üzerine sezyum adsorpsiyonu çalışmaları yapılmıştır. Adsorpsiyondan elde edilen veriler Langmuir ve Freundlich izoterm modellerine uyarlanmıştır. Nanokompozit adsorban sezyumun adsorpsiyonunda kullanılması neticesinde maksimum adsorpsiyon kapasitesine Cs+ için 34,36 mg.g-1'da ulaşmıştır. Sezyumun nanokompozit üzerine adsorpsiyonu Langmuir izotermine daha iyi uyduğu sonucuna varılmıştır. Nanokompozit adsorban üzerine sezyum adsorpsiyonunda serbest enerji (ΔG), entropi (ΔS) ve entalpi (ΔH) değişimi gibi termodinamik parametreler incelendi. ΔH0 değeri negatif ve ΔS0 değerinin pozitif olması ekzotermik ve kendiliğinden özellikte adsorpsiyon mekanizmasının gerçekleştiğini, ΔH0 değerinin negatif ve ΔS0 değerinin pozitif olmasının yanısıra ΔG0 değerinin de negatif olması adsorpsiyonun tüm sıcaklıklarda kendiliğinden gerçekleştiğini gösterir. İlave olarak düşük adsorpsiyon entalpisi sebebiyle sezyum, nanokompozit üzerine fiziksel olarak adsorplanmaktadır. Yabancı iyon etkisiyle sezyumun nanokompozit üzerine adsorpsiyonda düşüş olduğu gözlenmiştir. Kolon çalışmalarından elde edilen adsorpsiyon kapasitesinin daha önce elde edilen adsorpsiyon kapasitesinden daha düşük olduğu belirlenmiştir. En düşük desorpsiyon değeri nötr ortamda tespit edilmiştir.
  • Öge
    New methodologies for macro and micro structured hyperbranched polymers
    (Lisansüstü Eğitim Enstitüsü, 2021) Bener, Semira ; Yağcı, Yusuf ; 671614 ; Kimya
    Branching has great importance in synthetic macromolecular chemistry as well as in nature. Hyperbranched polymers (HBPs), an established class of dendritic macromolecules, are highly branched specialty products. Accordingly, they have received significant interest due to their unique dendritic structures and superiorities such as high solubility, low viscosity and abundant terminal groups with high functionality. Due to their special properties, they allow designing and development of new branched architectures by modification of the terminal groups. Benefiting from their unique features and key functionalities, HPBs have been employed in many fields ranging from biological applications to nanotechnology. Synthetic approaches to produce HBPs have been broadened from typical Flory approach or a classical approach (i.e., chain transfer reactions) to various polymerization techniques such as azide-alkyne, thiol-ene/yne or Diels-Alder cycloadditions. However, there have been limited efforts to apply light-induced processes to conventional methods. Nevertheless, photochemical strategies provide desirable advantages including temporal and spatial control of the reactions, high reaction rates, low energy requirement and environmental benefits. In this context, highly branched and network structures were produced by using photochemical methods in the thesis. In the first part of the thesis, a simple photochemical route for the synthesis of hydrophilicity tunable hyperbranched polymers is introduced. This methodology is based on the copolymerization of tert-butyl acrylate (tBA) as monomer and 2-(2-bromoisobutryloxy)ethyl methacrylate (BIBEM) as inimer, by using photo-induced self-condensing vinyl copolymerization (SCVP) with manganese decacarbonyl. Hydrophilicity tunable hyperbranched polymers are obtained by means of hydrolysis of the tert-butyl ester moieties of the hydrophobic hyperbranched copolymers. The branching density and hydrophilicity of the resulting hyperbranched polymers were investigated in detail by changing the inimer concentration and irradiation time. The precursor and hydrolyzed hyperbranched polymers were characterized by spectroscopic, chromatographic and contact angle measurements. In the second part of the thesis, as part of the continuing study of the synthesis of branched and network architectures, a novel photochemical application of N-acyl dibenzazepine (ADBA) chemistry for preparing photo-reversible ADBA and thiol-ene based networks was explored. Formation of cross-linked ADBA based thiol-ene networks was successfully achieved through UV-induced dimerization of ADBA groups at wavelengths above 300 nm while a well-defined cleavage of the network occured by means of a subsequent deep UV exposure ( λ=250). Dimerization and cleavage processes were confirmed by spectroscopic investigations and final products were characterized in detail. Finally, a novel and straightforward approach using photolatent inimer in conjunction with vinyl monomers for the synthesis of hyperbranched polymers (HBPs) through light-induced self-condensing vinyl polymerization (SCVP) methodology is reported. The process is based on SCVP technique using an (photolatent) inimer possessing divinyl functionality, which acts as both initiator and monomer. HBPs with desired branching densities were fabricated by changing photolatent inimer content and irradiation time. Simple strategy described may lead to new applications in bio-related fields requiring hyperbranched structures without contamination of low molecular weighted photoinitiator fragments.
  • Öge
    4-(triflorometoksi)fenoksi grupları içeren ftalosiyaninlerin sentezi, tıpta, biyolojide ve ileri teknolojide kullanılabilirliklerinin araştırılması
    (Lisansüstü Eğitim Enstitüsü, 2021) Farajzadeh, Nazlı ; Koçak, Makbule ; 675427 ; Kimya
    Ftalosiyaninler (Pcs) ve onların metalli türevleri benzersiz optik, elektronik, katalitik ve yapısal özelliklerinden dolayı son yıllarda büyük ilgi çekmektedir. Geleneksel olarak, ftalosiyaninler boya ve pigment olarak kullanılmıştır, fakat son zamanlarda kataliz, sıvı kristaller, kimyasal sensörler, fotodinamik tedavi, güneş enerjisi dönüşümü, optik veri depolama, yarı iletkenler ve nonlineer optik gibi farklı bilimsel ve teknolojik alanlarda geniş uygulama alanı bulmuşlardır. Ayrıca, metal ftalosiyaninler, elektrokatalitik, elektrokromik ekranlar ve sensör uygulamaları gibi çeşitli elektrokimyasal teknolojilerde işlevsel malzemeler olarak yaygın bir şekilde kullanılmaktadır. Metal ftalosiyaninlerin redox zenginliği, bu uygulamalardaki işlevsellikleri için anahtar faktördür ve bu özellikler, metal merkezler ve sübstitüentler değiştirilerek kolayca uyarlanabilir. Son yıllarda, araştırmacılar Pc moleküllerinin antioksidan, antimikrobiyal ve enzim inhibisyon aktivitelerini de incelemiştir. Reaktif oksijen türleri (ROS), canlı organizmaların metabolizmalarında üretilir ve bu ROS, hücresel biyomoleküllerin çoğu ile kolayca reaksiyona girerek bir organizmanın normal savunma mekanizmalarını azaltır. Çoklu ilaç direnci ile sonuçlanan ticari antibiyotik ilaçların yaygın kullanımı nedeniyle, antimikrobiyal aktiviteye sahip yeni Pc'lerin sentezi önemli hale gelmiştir. Düzlemsel makrosiklikler arasındaki π istiflenme (kümelenme) nedeniyle, sübstitüe edilmemiş ftalosiyaninler, organik çözücülerde ve suda çözünmez veya az çözünür, bu durum onların uygulamalarını sınırlandırmıştır. Makrosikliklerin periferal veya eksenel olarak sübstitüe edilmesi, 18π - elektron konjüge sistemleri arasındaki mesafeyi arttırır, kümelenmeyi azaltır böylece çeşitli çözücülerde çözünürlüklerini arttırır ve optik özelliklerini geliştirir. Flor atomları, yüksek oranda elektron çekme özelliğine sahiptir ve florlu Pc'ler için olağanüstü elektron geçişi, manyetik ve ışığa duyarlılık özellikleri sunar. Ayrıca, multi-floro-sübstitüe ftalosiyaninler mükemmel termal stabilite, kimyasal direnç ve polar/apolar çözünürlük gibi benzersiz özellikler gösterdiklerinden yeni malzemeleri üretmek için flor içeren Pc'lerin geliştirilmesine odaklanan çalışmaların sayısında son zamanlarda büyük bir artış vardır. Bu tez kapsamında fotodinamik terapide, biyolojide ve yüksek teknolojide kullanılabilme potansiyellerini araştırmak amacıyla, ikisi asimetrik ve 26 sı yeni olmak üzere 27 adet ftalosiyanin bileşiği sentezlendi. Bu amaçla tezin birinci aşamasında 4-nitroftalonitril veya 3-nitroftalonitril ile 4-(triflorometoksi)fenol kuru dimetil formamid (DMF) içerisinde, potasyum karbonat varlığında, azot atmosferi altında, 45 oC de reaksiyona sokularak, sırasyla 4-(4-(triflorometoksi) fenoksi) ftalonitril (1) ve 3-(4-(triflorometoksi) fenoksi) ftalonitril (2) bileşikleri sentezlendi. 4,5 dikloroftalonitril ile 4-(triflorometoksi)fenol kuru dimetil sülfoksit (DMSO) içerisinde, potasyum karbonat varlığında, azot atmosferi altında, 80 oC de reaksiyona sokularak 4,5-bis(4-(triflorometoksi)fenoksi) ftalonitril (3) bileşiği hazırlandı. Elde edilen 1, 2 ve 3 nolu ftalonitrillerin ilgili metal tuzları (metalsiz ftalosiyain için metal tuzu kullanılmadan) ile uygun çözücülerde (pentanol katalitik miktarda DBU, dimetilaminoetanol ve kinolin) azot atmosferi altında ve uygun sıcaklıklarda (135 oC, 165 oC, 170 oC) siklotetramerizasyon reaksiyonları sonucu hedeflenen simetrik mono metalli (1-Zn, 2-Zn, 3-Zn, 1-Co, 2-Co, 3-Co, 1-Cu, 2-Cu, 3-Cu, 1-Pd, 3-Pd, 1-Ga, 2-Ga, 3-Ga, 1-In, 2-In, 3-In, 1-Lu, 2-Lu, 3-Lu), metalsiz (1-H2, 2-H2), ftalosyaninler ve sandviç tipi lutesyum ftalosiyaninler (1'-Lu, 2'-Lu, 3'-Lu) sentezlendi. Yine bu aşamada elektron itici gruplar içeren 4-(triflorometoksi)fenoksi)ftalonitril (1), 4,5-bis(4 triflorometoksi)fenoksi)ftalonitril ligantları (3) ve elektron çekici 4-((4-nitrofenil)etinil)ftalonitril ligantı (4) ile istatiksel kondenzasyon yöntemi kullanılarak A3B tipi halka dışı üçlü bağlar içeren push-pull yeni asimetrik çinko ftalosiyaninler sentezlendi. Reaksiyon 135 oC de azot altında DMAE içinde gerçekleştirildi. Sentezlenen bütün moleküllerin saflıkları ince tabaka kromatorafisi ile takip edilip, yapıları Ft-ır, 1H NMR (paramamanyetik ftalosiyaninler hariç), 13C NMR (paramamanyetik ftalosiyaninler hariç), kütle spektroskopisi ve UV-vis gibi spektral teknikler kullanılarak aydınlatıldı. Sandviç tipi lutesym ftalosiyaninlerin (1'Lu-3'Lu) yapılarını aydınlatmak için elektro spin resonas ölçümleri (ESR) de kullanıldı. Sentezlenen ftalosiyaninlerin elektronik spektrumları, farklı çözücülerde ve farklı derişimlerde UV-vis spektrometresi aracılığıyla ölçülerek çözücünün cinsinin ve derişiminin spektoskopik ve agregasyon (kümeleşme) özellikleri üzerindeki etkisi araştırıldı. Tezin ikinci aşamasında sentezlenen ftalosiyaninlerin biyolojide kullanılabilme potansiyellerini araştırmak amacıyla 1, 1-H2, 1-Cu, 1-Pd bileşiklerinin antioksidan aktiviteleri ve tirozinaz inhibisyon özellikleri, 3, 3-Zn, 3-Cu, 3-Co bileşiklerinin antimikrobiyal ve antioksidan aktiviteleri incelendi. Ayrıca 4 veya 3 konumlarında 4-(triflorometoksi)fenoksi (1,2) veya 4-(triflorometoksi)tiyofenoksi gruplarını (1S, 2S) içeren ftalonitrillerden hazırlanan metalsiz ve bakır ftalosiyaninlerin (1-H2, 1-Cu, 2-H2, 2-Cu, 1S-H2 , 1S-Cu, 2S-H2, 2S-Cu) bağlayıcı atomun cinsinin ve konumunun bu bileşiklerin biyolojik özelliklerinin üzerindeki etkisini incelemek için antioksidan ve tirozinaz inhibisyon aktiviteleri araştırıldı. Tezin üçüncü aşamasında, fotodinamik terapide kullanılabilme potansiyellerini araştırmak amacıyla, 1-Zn, 1-InCl, 1-Ga, 1-Lu, 2-Zn, 2-InCl, 2-Ga, 2-Lu, 3-Ga, 3- Lu bileşiklerinin, UV-vis ve floresans spekroskopisi kullanılarak, floresans kuantum verimleri, singlet oksijen kuantum verimleri ve fotobozunma kuantum verimleri hesaplandı. Ayrıca bu tez kapsamında, ilk defa, mono lutesyum ftalosianinlerin (1-Lu, 2- Lu, 3- Lu) SPDT'de kullanılabilme potansiyellerini araştırmak amacıyla, fotofiziksel ve fotokimyasal özellikleri incelendi. Tezin dördüncü aşamasında sentezlenen ftalosiyaninlerin elektrokataliz, elektroalgılayıcı, görüntüleme ve optoelektronik alanlarında kullanılabilme potansiyellerini araştırmak amacıyla 1-Zn, 1-Co, 1-In, 2-Zn, 2-Co, 2-In, 3-Zn, 3-Co, 3-In bileşiklerinin elektrokimyasal ve in-situ spektroelektrokimyasal özellikleri incelendi. Tezin son aşamasında ise 1 ve 3 nolu ftalonitrillerden hazıralana simetrik ve A3B tipi asimetrik çinko ftalosiyaninlerin (1-Zn, 3-Zn, 1-AZn, 3-AZn) non lineer optik malzemeler olarak kullanılabilme potansiellerini arştırmak amacıyla NLO ve optik sınırlama özellikleri açık yarık Z-tarama yöntemi kullanılarak incelendi.
  • Öge
    Synthesis of boron containing phthalocyanines
    (Lisansüstü Eğitim Enstitüsü, 2021) Özgür, Nilgün ; Hamuryudan, Esin ; 675444 ; Kimya
    Phthalocyanines, which is a kind of tetrapyrrole derivatives, constitute one of the important topics for both basic science and applied studies in recent years. 2-dimensional π-electron delocalization on phthalocyanines causes a large increase in their rare physical properties, resulting in many different applications from industry (batteries, inks) to medicine (BNCT, PDT). In recent years, the use of asymmetric or low-symmetry phthalocyanines, which are named in this way due to the difference of the substituted groups in the peripheral and non- peripheral position, in areas such as nonlinear optics (NLO), PDT, BNCT has led to intense research on this subject. The lack of solubility of Pcs without substituents in common solvents prevents the investigation of the properties of them and their use for different applications. Therefore, the most important goal of research has been to obtain soluble products. Phthalocyanines (Pc) and their metal complexes (MPc) can be readily modified by adding metal atoms to the central space and various groups on the peripheral and nonperipheral positions. Thus, they offer a wide range of uses from molecular science to medicine. The low solubility of phthalocyanine derivatives in water makes the purification and characterization stages difficult and provides disadvantages in biological applications. The inability of phthalacyanins to show high affinity to tumor cells due to their lipophilic properties necessitates the synthesis of their water-soluble derivatives. Although many procedures were discovered for the preparation of symmetric substituted Pcs, a few procedures can be used to synthesize asymmetric Pcs. These methods also differ according to the type of product targeted for synthesis. For the synthesis of A3B type asymmetric phthalocyanine containing two different substituents, the most applicable method is the cyclotetramerization of the starting materials containing these substituents. The most important problem in this procedure is the difficulty in separating the targeted Pcs from the isomer mixture that has exactly similar physicochemical properties. Although the widely used statistical condensation method is not a selective synthesis method for the target Pc, the yield of the desired asymmetric compound can be increased with the proportional change of the starting materials. BNCT, developed by taking advantage of boron properties, is a two parts cancer treatment method. The first of these parts is the stable boron isotope (10B) accumulating in tumor cells and the second is the low-energy neutron source. In this treatment method, non-radioactive 10B atoms are bombarded with thermal neutrons to form a high-energy α particle and an 11B isotope that breaks down into lithium ion. Research on BNCT has shown that high boron-containing compounds selectively accumulate in tumor cells, so the focus has been on the synthesis of these agents. Carboranes are rich in boron atoms as well as their characteristic features, which allows them to be used in BNCT applications. Compounds in which polyhedral boron structures are covalently bonded to metal phthalocyanines are potential products that can be used in areas such as PDT and BNCT. While examples of porphyrins containing polyhedral boron are frequently encountered in the literature, phthalocyanine derivatives are limited to a small number of examples. Generally, two methods are used in the preparation of carborane containing phthalocyanines. In the first method, after the phthalocyanine synthesis is completed, the carborane unit is attached to the structure, while in the second method, phthalocyanine synthesis is carried out based on the phthalonitrile derivative containing carborane. Within the scope of this thesis, it is aimed to investigate the synthesis, characterization, and properties of carborane groups that have the potential to be used in BNCT and asymmetrical phthalocyanines substituted with groups that provide solubility and interaction with target cells. The studies consist of four parts. The first part covers the synthesis of phthalonitrile derivatives and carborane derivatives as starting materials, while the second part covers the synthesis of new unsymmetrical metal-free and metallophthalocyanines with an A3B-type structure as a result of cyclotetramerization of dinitrile derivatives by statistical condensation method. The third part includes the preparation of phthalocyanine derivatives functionalized with carborane and metallocarborane groups and in the last part, electrochemical studies of some selected compounds are displayed. In the first part, phthalonitriles which are starting molecules in the synthesis of the targeted phthalocyanine compounds are 4,5 di(hexylthio) phthalonitrile (1), 4 - [(2-hydroxyethyl) thio] phthalonitrile (2), 4- [3- (diethylamino) phenoxy] phthalonitrile (3) and cobaltocarborane compound which is a metallocarborane derivative with oxonium functional group was synthesized, and their structures were defined by spectrometric techniques and elemental analysis. In the second part, for the synthesis of unsymmetrical metal-free and metallo phthalocyanine derivatives, it was firstly started with the synthesis of two A3B type hexylthio-hydroxyethylthio (7) and diethylaminophenoxy-hydroxyethylthio substituted (10) unsymmetrical metal-free phthalocyanines, continued with multi-step reaction sequences and the structures were elucidated with spectroscopic methods. In the preparation of unsymmetrical metal-free Pc 7, primarily dilithium phthalocyanine was prepared by lithium template cyclotetramerization of hexylthio and hydroxyethylthio substituted phthalonitriles. After that, dilithium phthalocyanine was acidified with acetic acid to transform into metal-free phthalocyanine Pc 7. Column chromatography was used for the isolation of the product in 26% yield. Metallo phthalocyanine Pc 8 was prepared by refluxing Pc 7 in 1-pentanol with zinc(II) acetate under N2 atmosphere (94% yield). Newly synthesized phthalocyanine derivatives Pc 7 and Pc 8 were characterized by their spectral data and elemental analysis. Also, aggregation behavior of Pc 7 and Pc 8 was analyzed at different concentrations in chloroform. According to these results, Pc 7 and Pc 8 have monomeric structure and obey the Beer-Lambert law in this concentration range. Similarly, Pc 10 was prepared by cyclotetramerization of diethylaminophenoxy substituted phthalonitrile and hydroxyethylthio substituted phthalonitrile in 1-pentanol. Pc 11 was obtained by refluxing Pc 10 in dry pentanol with Zinc(II) acetate under N2 atmosphere. As a result, Pc 10 and Pc 11 were obtained in 21% and 89% yield, respectively. Steglich esterification is a general method of preparation of ester functional group under very mild conditions. By using this method, esterification of Pc 9 and Pc 13 was achieved by reacting the 4-pentynoic acid with Pc 8 and Pc 11 in the presence of DCC and DMAP. The urea derivatives formed during the reaction were easily removed by precipitation and column chromatography. Pc 9 and Pc 13 were obtained in 60% and 67% yield, respectively. Different methodologies to synthesize carborane containing phthalocyanines have been reported. One of them is the decaborane insertion to alkynyl units of the phthalocyanine derivatives. Therefore, Pc 12 including terminal alkynyl group was obtained from the reaction of propargyl bromide and Pc 11 with NaH in toluene. The purity of the Pc 12 was verified by spectroscopic and elemental analyses. In the third part, phthalocyanine derivatives 14 and 15 were synthesized by covalently linking the carborane units to unsymmetrically alkynyl substituted phthalocyanine complexes. Decaborane insertion to Pc 14 was carried out by reaction of Pc 9 and decaborane in a mixture of dry C2H3N and dry C7H8. By using the same method, Pc 15 containing mono o-carboranyl unit was prepared in 68% yield. Characterization of the products was carried out by elemental and spectral analysis, and mass spectroscopy. Spectral analyses for novel phthalocyanines were compatible with the targeted structures. One of the most important necessity for BNCT agents is the water solubility of the synthesized compounds. For this purpose, tricationic water soluble Pc 16 was obtained by quaternarization of diethylamino substituted Pc 15. The reaction was carried out by heating Pc 15 with methyl iodide for 2 days in chloroform at 50 ° C in 84% yield. The characterization and purity of the resulting water-soluble compound has been demonstrated by techniques including 1H NMR, 11B NMR and UV-Vis. In addition, in this part, molecules bearing the "cobaltocarborane" group, which have similar properties to carborane but allow more boron atoms to be loaded in a single molecule, were also synthesized. Cobaltacarborane functionalized metallophthalocyanine complexes Pc 17 and Pc 18 were prepared from Pc 8 and Pc 11. In these reactions, hydroxyl groups in Pc 8 and Pc 11 attacked to the oxonium units of cobalt bis(dicarbollide). A3B-type Pc 17 and Pc 18 were purified by using DCM as mobile phase with 52% and 73% yields, respectively. Electrochemistry provides important information on the redox behavior of phthalocyanine and carborane compounds. Lastly, the electrochemical properties of newly synthesized unsymmetrical phthalocyanine 8, 9, 14 and 17 were reported. The reduction and oxidation potentials of phthalocyanine complexes were studied by CV and SWV in dichloromethane using TBAP as supporting electrolyte system and platinum working electrode. Consequently, within the scope of this doctoral thesis, the synthesis, characterization and research of the electrochemical features of phthalocyanine derivatives containing the substituent groups that provide both interaction with target cells and solubility in organic solvents and water and carborane units required for BNCT were carried out.
  • Öge
    Development and functionalization of novel polymeric materials from poly(oxazoline)s for potential bioapplications
    (Lisansüstü Eğitim Enstitüsü, 2020) Özköse, Umut Uğur ; 659578 ; Kimya Ana Bilim Dalı
    The polyoxazoline polymers (POx) were discovered as poly(N-acylethylenimine) in 1966, and have caught researchers' attention only in recent years. This is because they stand out in many ways as they exhibit high biocompatibility, stealth effect, narrow molecular weight distribution, responsiveness to pH and temperature, high functionalization and copolymerization and versatility. To this respect, they became a popular choice to replace polyethylene glycol (PEG), which infamously suffer from oxidation under in vivo conditions. As a nutritional supplement, poly(2-ethyl-2-oxazoline) (PEtOx) was ratified by FDA, and it is expected that the biomaterials depending upon PEtOx will improve very swiftly with the assent of PEtOx for medical use. It is known that polyoxazolines exhibit very good cellular compatibility for in vitro studies due to their stealth behavior similar to PEG and their structure mimicking peptide. In vitro cytotoxicity studies of PEtOx and their derivatives were generally found to be quite low and PEtOx is the one of most studied polymers for in vivo toxicity. In addition, it was determined that repeated intravenous injections of high dose (2g / kg) to rats, did not cause side-effects on animals and no difference in histological applications in liver, spleen and kidney compared to animals of control group. Within the scope of this thesis, three different studies based on PEtOx were conducted: The first study states that poly(2-ethyl-2-oxazoline)/clay (PEtOx/MMT) nanocomposites were developed for the first time. The living cationic ring-opening polymerization (CROP) of 2-ethyl-2-oxazoline was initiated by the tosyl-functionalized montmorillonite clay, then silicate layers were delaminated in the polymer matrix and nanocomposites were formed. The obtained nanocomposites have been investigated in means of thermal and morphology properties by utilising DSC, TGA, XRD, and TEM. All PEtOx/MMT nanocomposites consisting both intercalated and exfoliated silicate layers have an enhanced thermal stability. In the second part of this thesis, PEtOx based-amphiphilic block copolymers and synthetic routes that enable to reach them were certificated. In this context, a novel procedure was created for the preparation of poly(2-ethyl-2-oxazoline)-block-poly(ε-caprolactone) (PEtOx-b-PCL) to manage the molecular architecture. Hereof, a new electrophilic moiety functionalized PEtOx-b-PCL derivative was described. This methodology opened a way to prepare biomolecule conjugated block copolymers that have enormous importance for various applications. Amphiphilic block copolymers are shown to self-assemble into various morphologies, comprising ellipsoids, tubular structures, toroids, vesicles, micellar structures. In this study, we discuss the preparation PEtOx-b-PCL based copolymeric nanostructures (CNs). Our data indicate that – varying the molecular weight and the number of repeating units dictate the nature of morphology. That is, the formation of self-assembled morphologies from ellipsoid to rod-like architectures are observed in aqueous solution, contingent on the mass ratio of hydrophilic block to total block copolymer (fPEtOx). To best of our information, this is the first document on the morphological transitions of PEtOx-b-PCL amphiphilic block copolymer-based CNs with different fPEtOx values in the literature.