Simetrik ve push pull tipi asimetrik ftalosiyaninlerin sentezi ve nonlineer optik özelliklerinin incelenmesi
Synthesis of synthetic and push pull type asymmetric phthalocyanines and investigation of nonlinear optic properties
Yazar: EDA KORKMAZ
Danışman: PROF. DR. MAKBULE KOÇAK
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Kimya Ana Bilim Dalı / Kimya Bilim Dalı
Derece: Yüksek Lisans, 2019
Konu: Kimya = Chemistry

Özet:
Ftalosiyaninler (Pc) kimyasal direnç, ısıl kararlılık, elektriksel ve optik özellikleri sayesinde birçok uygulamada kullanılan mavi-yeşil renkli makrosiklik yapılardır. Bu yapılar gaz sensörleri, fotovoltaik hücreler, elektrokromik görüntüleme cihazları, yarı iletkenler, optik diskler, nonlineer optik ve fotodinamik terapi gibi uygulama alanlarında büyük ilgi görmektedir.
Sübstitute olmamış ftalosiyanin bileşiklerinin hem çözeltide hem de katı haldeki moleküler kümeleşmesinden dolayı polar ve apolar çözücülerdeki düşük çözünürlüğü, bu bileşiklerin optik özelliklerinde ciddi bir zayıflamaya neden olmakta ve kullanımlarını kısıtlamaktadır. Periferal, nonperiferal ve eksenel konumlara çeşitli gruplar ilave edilerek moleküller arası mesafesi artan ftalosiyanin bileşiklerinin, apolar çözücülerde, polar çözücülerde ve suda çözünmeleri sağlanmakta ve kümeleşmeleri engellenmektedir. İlave edilen gruplar ftalosiyanin bileşiklerinin sadece çözünürlüğünü arttırmaz elektronik yapısını da değiştirir, böylece uygulama alanları da genişlemiş olur.
Bu tez çalışmasında ilk olarak, literatürde yer alan gerekli başlangıç maddeleri için 4-( 3,5-bis(triflorometil)fenoksi ) ftalonitril (1) bileşiği 4-dikloroftalonitril ve 3,5-bis(triflorometil)fenoksi bileşiklerinin 45 °C' de kuru N2 atmosferinde DMF ile reaksiyonu sonucunda sentezlenmiştir. Elde edilen bu ftalonitril bileşiğinden InCl3 ve Zn(CH3COO)2 varlığında sırasıyla pentanol ve 2-(dimetilamino) etanol (DMAE) içerisinde 150°C ve 135°C'lerde 24 saaat süren siklotetramerizasyonuyla sırasıyla çinko ftalosiyanin (3) ve indiyum ftalosiyanin (4) bileşikleri sentezlenmiştir.
İkinci olarak, 4-((4-nitrofenil)etinil) ftalonitril (2) bileşiği literatüre göre sentezlenmiştir. Bu ftalonitril türevi ve 4-( 3,5-bis(triflorometil)fenoksi ) ftalonitril kullanılarak Zn(CH3COO)2 varlığında DMAE içerisinde 135 °C'de azot atmosferindeki reaksiyonu sonucunda asimetrik çinko ftalosiyanin (5) bileşiği elde edilmiştir.
Çalışmanın üçüncü kısmında, elde edilen bileşikler THF çözeltisi içerisinde çözünmüş ve açık Z-tarama yöntemiyle üçüncü derece NLO özellikleri incelenmiştir. Daha sonra çözeltilerin bir konsantrasyon değeri için Optik Sınırlayıcı özellikleri (optical Limitting) ölçülmüştür.
Sonuç olarak bu tez çalışmasında yeni bir ftalonitril türevinden simetrik çinko ve indiyum ftalosiyanin ve asimetrik çinko ftalosiyaninler sentezlenmiştir. Sentezlenen bileşiklerin IR, UV-Vis, NMR, GC-MS ve MALDI-TOF teknikleriyle karakterizasyonları yapılmıştır. Simetrik ve asimetrik çinko ftalosiyaninlerin üçüncü dereceden NLO özellikleri ve optik limit özellikleri incelenmiştir.

Abstract:
Phthalocyanines (Pc) are blue-green colored macrocyclic structures used in many applications due to their chemical resistance, thermal stability, electrical and optical properties. These structures are of great interest in applications such as gas sensors, photovoltaic cells, electrochromic imaging devices, semiconductors, optical discs, nonlinear optics and photodynamic therapy.
Phthalocyanines are aromatic and planar compounds having a conjugated 18 π-electron system consisting of four isoindole units connected by aza bridges in the 1,3 position.
Although phthalocyanines are structurally similar to porphyrins, they are not naturally found, such as vitamin B12, hemoglobin and chlorophyll A, and are completely synthetic products. The most important common feature of phthalocyanine and porphyrin macro rings is that they both contain four pyrrole units. In porphyrine pyrrole groups are connected to each other by text bridges while phthalocyanine is connected to each other by aza bridges.
Metallic phthalocyanine compounds (MPc) have D4h symmetry, while metal-free (H2Pc) phthalocyanines have D2h symmetry. There are many different crystal structures with different properties such as solubility, color and thermodynamic stability according to synthesis shape.
Metallic phthalocyanines are divided into two groups as electrovalent and covalent. Electrovalent phthalocyanines. Contains ions of certain alkali and alkaline earth metals. Dilute inorganic acids are readily separated from the metal ion which reacts with aqueous alcohol and water to form metal-free phthalocyanine compounds. Unlike rechargeable electrovalent phthalocyanines, lithium phthalocyanines contain alcohol, which can dissolve in the room and react with other metal salts. Covalent phthalocyanine complexes are more stable than electrovalent ones. Such phthalocyanines are difficult to remove ring-containing metal by treating with acids.
Phthalocyanines are resistant to strong acids and bases. They are not only resistant to strong oxidizing reagents (HNO3 and KMnO4) and decompose to phthalimide, the oxidation product.
The low solubility of unsubstituted phthalocyanine compounds in polar and apolar solvents due to molecular agglomeration of both the solution and the solid state leads to a significant weakening of the optical properties of these compounds and restricts their use. Various groups are added to the peripheral, nonperipheral and axial positions to ensure that the intermolecular distance of the phthalocyanine compounds is dissolved in apolar solvents, polar solvents, and water and aggregation is prevented. The added groups not only increase the solubility of the phthalocyanine compounds,
but also change the electronic structure, thereby extending the application range.
In general, phthalocyanines are obtained from ortho dicarboxylic acid derivatives such as phthalonitriles, phthalic anhydrides, phthalic acids, diiminoisoindolines, o-cyanobenzamides and phthalimides by a high boiling solvent or direct heating.
Optics is a branch of physics that studies the interaction of light with substances, the construction of materials that are affected by light or use it as part of light. It is possible to make optical materials by using the refraction, scattering and dispersion properties of light. After the discovery of laser by Mainman in 1960, nonlinear optics (NLO), a branch of optics and used in fields such as photonics, photoelectronics, has recently become a prominent field.
Nonlinear optics (NLO) can be defined as a result of changing the optical properties of materials in the presence of light. In other words, dielectric polarization (P) is the non-linear response of light to the electric field (E). NLO activity was first discovered with inorganic crystals such as LiNbO3 (Lithium Niobate). However, the variety of such materials is very limited. Furthermore, the disadvantage is that most of the inorganic materials have low NLO response and have to be processed as thin films in order to be used in microelectronic devices. In 1970, Davydov first demonstrated the second order harmonic production (SHG) in organic molecules containing rotating and acceptor groups, increasing interest in organic materials for NLO applications. Organic materials with a strong and rapid NLO response have many advantages, such as economic and easy processing for the preparation of films, combined with very small optical devices.
The strong nonlinearity of organic materials generally results from highly delocalized π systems. Phthalocyanines with dense 2-dimensional 18 π-electron systems meet these needs and gain much interest in the study of NLO materials.
The NLO behavior of a molecule depends on the order of electronic energy levels. Phthalocyanines also have strong Q and B bands in the linear optical spectra resulting from the transition π-π *, which are around 670 nm and 340 nm respectively. These bands determine the NLO characteristics of the Pcs. In addition, the stability of phthalocyanines, their ability to bind with various metal atoms and the addition of substituents to various positions allows their chemical structure and NLO behavior to be regulated.
In this thesis, 4- (3,5-bis (trifluoromethyl) phenoxy) phthalonitrile compound was first synthesized by reaction of 4-dichlorophthalonitrile and 3,5-bis (trifluoromethyl) phenoxy compounds with DMF at 45 oC in dry N2 atmosphere. Potassium carbonate was chosen as the base for this reaction. Symmetrical indium and zinc phthalocyanines were obtained by cyclotetramerization of this phthalitrile derivative in the presence of InCl3 and Zn (CH3COO)2 in pentanol and 2- (dimethylamino) ethanol (DMAE) at 150 °C and 135 °C for 24 hours.
Secondly, 4 - ((4-nitrophenyl) ethynyl) phthalonitrile was synthesized according to the literature. Using this phthalonitrile derivative and 4- (3,5-bis (trifluoromethyl) phenoxy) phthalonitrile, asymmetric zinc phthalocyanine was obtained in the presence of Zn(CH3COO)2 in DMAE at 135 ° C in a nitrogen atmosphere.
Thirdly, as a result of open slit experiments of solutions prepared at different concentrations of phthalocyanine compounds dissolved in THF; NLO properties were investigated.
As a result, symmetric zinc and indium phthalocyanines and asymmetric zinc phthalocyanines were synthesized from a new phthalonitrile derivative. The synthesized compounds were characterized by IR, UV-Vis, NMR, GC-MS and MALDI-TOF techniques. Third degree NLO properties and optical limit properties of symmetric and asymmetric zinc phthalocyanines were investigated. According to the values of the second-order absorption coefficient and the virtual term of the third-order NLO-sensitivity; As the concentration of symmetric and asymmetric phthalocyanines increased, the second-order absorption coefficient and the virtual term values of the third-order NLO-sensitivity increased, and the NLO properties of symmetric and asymmetric phthalocyanines were similar.