Antrakinon türevli çinko ftalosiyanin tabanlı florometrik voltametrik ve çift kanallı eser miktar su sensörünün geliştirilmesi
Anthraquinone substituted zinc phthalocyanine and its trace amount of water detection sensor abilities based on double channel fluorometric and voltammetric methods
Yazar: MUSTAFA SEMİH YILDIRIM
Danışman: PROF. DR. İSMAİL YILMAZ
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Kimya Ana Bilim Dalı / Kimya Bilim Dalı
Derece: Yüksek Lisans, 2020
Konu: Kimya = Chemistry
Dizin: Elektrokimya = Electrochemistry ; Floresan = Fluorescence ; Ftalosiyaninler = Phthalocyanines

Özet:
Ftalosiyanin bileşiği, 1907 yılında asetik asit ve ftalimit'ten o-siyanobenzamidin sentezi sırasında yan ürün olarak ilk kez ortaya çıktığı günden beri çok sayıda alanda ve konuda çalışma yapılmıştır.
Merkezindeki kavite birçok metal atomu ile kompleks yapabilecek kadar genişlikte ve dört adet azot atomu içeren iminoizoindolin birimlerinden oluşan makro halkalı yapı, simetrik olup pirol üniteleri doğrudan kompleksleşmede yer alır.
Ftalosiyaninlerin uzun ömürlü olmaları fotofiziksel ve fotokimyasal açıdan kararlı makro halkalı yapı olmalarından kaynaklanmaktadır. Bu halkalı yapının konjuge18-π elektron sistemi sayesinde görünür bölgede şiddetli bir şekilde ışıma ve emilim özellikleri mevcuttur. Ayrıca halkalı yapının çevresel ve çevresel olmayan konumlarına çeşitli sayıda ve özellikte fonksiyonel gruplar takılarak, ayrıca merkez metal atomu değiştirilerek fotofiziksel ve fotokimyasal özellikleri hassas bir şekilde ayarlanabilir. 
Kinon türevleri zengin elektrokimyasal özelliklere sahip organik bileşiklerdir. Canlılar içinde fotosentez ve solunum gibi süreçlerin elektron transfer mekanizmalarında hayati rollere sahiptirler. Tersinir elektrokimyasal süreçlere sahip olmaları bu bileşiklerin birçok alanda kullanılmasına sebep olmuştur. Ayrıca kinon türevlerine takılan elektron çekici ve verici gruplarla potansiyel değerleri kontrol edilebilir. 
Organik çözücüler için en yaygın safsızlık sudur. Petrokimya, ilaç, organik sentez vb. endüstriyel üretimler başta olmak üzere suyun varlığı ve miktar analizi büyük önem arz etmektedir. Geleneksel olarak kullanılan yöntem Karl-Fisher metodu olmakla beraber son dönemde özellikle floresan spektroskopisine dayalı birçok su sensörü geliştirilmiştir. Karl-Fisher metodu süre alan, karmaşık ve toksik çözeltiler gerektirmesi bu alana yönelimde etkili olmaktadır. 
Buna bağlı olarak, bu tez çalışması kapsamında çift kanallı hem floresan hem de voltametrik olarak su analizi yapabilen sensör geliştirilmiştir. Tetra antrakinoksi substitüe çinko ftalosiyanine dayalı olan sensör yüksek verimle sentezlenmiştir. Bileşik yapısı IR, GC-MS, NMR, UV-Vis gibi spektroskopik yöntemlerle aydınlatılmıştır. Moleküler yapı tayin edildikten sonra THF çözücüsü içerisindeki eser miktarda suyun analizini gerçekleştirilmiştir. Öncelikle ftalosiyaninlerin genel bir davranışı olan polar çözücülerde agregasyon eğilimi göz önünde bulundurulmuş ve en polar çözücü olan su varlığında agregasyondan kaynaklı floresan sönümlenmesi incelenmiştir. Düzlemsel yapısı 2-hidroksi antrakinon grubu varlığında genişletilmiş olan ftalosiyanin su varlığında şiddetli bir sönümlenmeye uğramıştır. Daha sonra ppm mertebesinde su ilaveleri ile titrasyon çalışması tamamlanmış ve sensörün su analitine karşı hassasiyeti ortaya konulmuştur.  Buradan hareketle tayin limiti 5,4 ppm olarak ve çalışma aralığı ise 0-4250 ppm olarak hesaplanmıştır. 
Daha sonra kinonların su varlığında elektrokimyasal davranışları göz önüne alınarak, DMF çözücüsü içerisindeki eser miktarda su analizi yapılmıştır. Yapının tersinir davranışları, potansiyel ve akım değerleri döngülü voltametre (CV) yöntemi ile belirlenmiştir. Daha sonra analitik çalışmalar için kare dalga voltametresi (SWV) yöntemi tercih edilmiştir. İlave edilen su miktarına bağlı olarak antrakinon grubunun indirgenme potansiyel değerleri pozitif alana doğru kayma göstermiş ancak ftalosiyanine ait indirgenme ve yükseltgenme potansiyelleri herhangi bir değişiklik göstermemiştir. Bu durumda ftalosiyanin indirgenme ya da yükseltgenme potansiyelleri iç referans olarak alınıp, ilave edilen suya karşı antrakinonun potansiyel değişimi üzerinden kalibrasyon grafiği elde edilmiştir. Genelde voltametrik analizlerde dışarıdan kararlı bir bileşik ilave edilip referans olarak alınır. Ancak geliştirilen sensör, sabit iç referansa sahip olması böyle bir harici referans ilavesine gerek bırakmamıştır. Voltametrik metotla yapılan sensör çalışmasında sensörün çalışma aralığı 0-46200 ppm olarak hesaplanmıştır. Böylece ftalosiyanin temelli floresan ve voltametrik olmak üzere çift kanallı hassas bir su sensörü literatüre kazandırılmıştır.

Abstract:
Phthalocyanine compound has been studied in many fields and subjects since the first time it appeared as a by-product during the synthesis of o-cyanobenzamide from acetic acid and phthalimide in 1907.
The cavity in its center is large enough to make complex with many metal atoms and the macrocyclic structure consisting of iminoisoindoline units containing four nitrogen atoms is symmetrical and pyrole units are directly involved in complexation.
The longevity of phthalocyanines is due to their being photophysically and photochemically stable macrocyclic structure. Thanks to the conjugated 18-π electron system of this cyclic structure, there is a strong emmision and absorption characteristics in the visible region. In addition, the functional and photochemical properties of the ring structure can be adjusted precisely by attaching functional groups with various numbers and features to the peripheral and non-peripheral positions of the annular structure, and also by replacing the central metal atom.
There are several ways to synthesize phthalocyanine compounds. One of the most commercially important of these is through phthalic anhydride and urea. Apart from that, Rosenmund-Von Braun synthesis can be considered quite practical. 2-cyanobenzamide as other starting materials and ptalonitrile derivatives can be counted as it is a very classic starting material, although difficult to obtain. 
While making phthalocyanine, it is possible to work with a lot of elements, including some semi-metals. However, there are some differences. One of these is the lower phthalocyanine (sub-Pc) structures obtained with small ions such as B3+, the upper phthalocyanine (super-Pc) structures obtained with large ions such as UO22+. There are three isoiminoindolin units in the lower phthalocyanines and five in the upper phthalocyanines.
Two characteristic peaks are observed in the electronic spectrum (UV) of phthalocyanine compounds. This process can even be used to simply check if the phthalocyanine compound is formed or to see if the phthalocyanine compound is metal-free or metallated. The first peak rises around 350 nm and it is called B band or Soret band. The second peak is between 650-700 nm and is known as the Q band. The feature of the Q band is that it is shaped according to the symmetry of the molecule.
Quinone derivatives are organic compounds with rich electrochemical properties. They play a vital role in the electron transfer mechanisms of processes such as photosynthesis and respiration in living things. Having reversible electrochemical processes caused these compounds to be used in many fields. In addition, electrochemical potential values can be controlled with electron donor and withdrawing groups attached to quinone derivatives.
Water is the most common impurity for organic solvents. Especially in industrial productions of petrochemical, pharmaceutical, organic compounds, etc. analysis of water and its quantity are of great importance. Although the traditional method is Karl-Fischer method, many water sensors based on fluorescent spectroscopy have been developed recently. The fact that the Karl-Fischer method takes time and requires complex and toxic solutions is effective in orientation to this area.
In molecular fluorescence spectroscopy, an atom or molecule induced by the electromagnetic beam increases from the basic energy level to the upper energy level. The excited atom or molecule at the upper energy level is unstable and wants to return to the basic energy level by removing the excess energy it absorbs. At this stage, all or some of the excess energy can be separated from the atom or molecule as light emission. Although this event is called fluorescence or phosphorescence depending on the type of realization, it is generally called luminescence. In this way, luminescence characters of the studied samples can be determined. 
Transition from a stimulated singlet system to a basic singlet system light emitted during fluorescence is called fluorescence. Fluorescence occurs in simple or complex gas, liquid and solid chemical systems. The simplest type of fluorescence is fluorescence indicated by dilute atomic vapors. For example, the 3s electrons of the vapor sodium atoms can be adapted to the 3p energy level by absorbing rays of wavelengths of 589.6 and 589 nm. After 10-5 - 10-8 seconds, the electrons return to the basic state and it emits rays of the same two wavelengths in all directions. This type of fluorescence, which involves the re-emission of the absorbed beam without change in frequency, is known as resonance radiation or resonance fluorescence. Many molecular species show resonance fluorescence. With it very often, molecular fluorescence or phosphorescence bands are centered at longer wavelengths than the resonance line. This shift to long wavelengths or low energies is referred to as stokes shift.
There are a lot of newly develop water fluorecense sensors that behave different type of fuorescense mechanisms. The most common types of fluorescense response mechanisms are photoinduced electron transfer (PET), intramolecular charge transfer (ICT) , excited state intramolecular proton transfer (ESIPT), and aggregation induced emmision (AIE). In addition of these type of mechanisms, several fluorosence probes have been working to develop more sensitive and selective to water depends on these rules or different and new type of response  mechanisms.
Accordingly, a new dual channels, fluorescent and voltammetry based sensor has been developed in this study. The sensor based on the tetra anthraquinoxy substituted zinc phthalocyanine was synthesized with a high yield. Characterization processes were performed with spectroscopic methods such as IR, GC-MS, NMR and UV-Vis. After confirming the molecular structure, the trace amount of water in THF solvent was analyzed. Firstly, the tendency of aggregation in polar solvents, which is a general behavior of phthalocyanines, was taken into consideration and the study of fluorescence quenching due to aggregation was investigated in the presence of water, which is the most polar solvent. The phthalocyanine, whose planar structure was expanded in the presence of anthraquinoxy group, was subjected to severe quenching in the presence of water. Then, titration study was completed with water additions in ppm level and the sensitivity of the sensor to water analyte was demonstrated. Based on this, the limit of detection (LOD) was calculated as 5.4 ppm and the working range was calculated as 0-4250 ppm.
Then, considering the electrochemical behavior of quinones and phthalocyanine in the presence of water, a trace amount of water analysis in DMF solvent was performed by electrochemisty. Reversible behavior, potential and current values of the structure were determined by cyclic voltameter (CV) method. Then, Square Wave Voltammetry (SWV) method was preferred for analytical studies. Depending on the amount of water added, the reduction potential values of the anthraquinone group shifted towards the positive side, but the reduction and oxidation potential of the phthalocyanine did not almost change. In this case, the reduction or oxidation potential of phthalocyanine is taken as an internal reference and calibration graph is obtained over the potential change of anthraquinone against the added water. In general, a reference compound such as ferrocene is externally added into solution in voltammetric analysis. However, the developed sensor, having a fixed internal reference, did not require the addition of such an external reference. In the sensor study performed by the voltammetric method, the working range was calculated as 0-46200 ppm. Thus, a phthalocyanine based fluorescent and voltammetric dual channel water sensor has been developed.