Floresans özellik gösteren bazı boranil bileşiklerinin sentezi
The synthesis of some boranil compounds that show flourescence property
Yazar: SAMET YUVAYAPAN
Danışman: DOÇ. DR. AYŞE ÖZDEMİR
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Kimya Ana Bilim Dalı
Derece: Yüksek Lisans, 2013
Konu: Kimya = Chemistry

Özet:
Floresans özellik gösteren boyalar uzun yıllardır çeşitli araştırma grupları tarafından incelenmektedirler. Bodipy boyaları ve bodipy ailesinin göstermiş olduğu enteresan fotoelektirik özellikler grubumuzu bu tarz boyaların çalışmasına yöneltmiştir.
Bor içeren bu grup boyaların göstermiş olduğu enteresan optoelektrik özellikler sayesinde sensörleme, güneş pilleri, fotodinamik terapi gibi uygulama alanlarında araştırma konusu olmuşlardır.
Bodipy ailesinden olan boranil türevlerini elde etmek için imin ( anil ) yapısı gerekmektedir. Salisil aldehit ve çeşitli aromatik primer aminlerle anil türevleri elde edilmiştir. Aynı zamanda salisil aldehitin türevlendirilmesiyle farklı anil türevlerinin sentezi gerçekleştirilmiştir. Bunun yanı sıra simetrik ikili imin ( anil ) türevleri benzidin, 4,4?-diaminometilen, o-fenilendiamin kullanılarak sentezlenmiştir.
Boranil türevleri imin türevleriyle sentezlenmiştir. Bu reaksiyonlarda imin türevi çıkış maddesi olarak kullanılmıştır. Sentez sırasında farklı yöntemler kullanılmıştır. Anil bileşiklerinin ikili olması sonucunda ikili boranil bileşikleri sentezlenmiştir.
Bu tez çalışmasında salisil aldehitin p-toluidin, o-anisidin, 2,4-dikloroanilin, benzidin, ?-naftilamin ile pH: 3-4 olan ortamda olan reaksiyonundan çeşitli imin türevleri elde edilmiştir.
Reaksiyon verimleri çok yüksek olup ikili imin türevlerinin verimlerinin çözücüye bağlı olduğu görülmüştür. Salisil aldehitle aromatik primer aminlerin reaksiyonu sonucu tek ürün elde edilmiştir ve ürünler katıdır. Ürünün katı olması saflaştırmasının kolay olmasını ve zaman tasarrufunu sağlamıştır.
Anil bileşiklerinin çeşitli spektrumlarla desteklenmesinin ardından sentezlenen imin (anil) bileşiklerinin bor komplekleri ( boranil ) elde edilmek istenmiştir.
Boranil bileşiklerini elde etmek için imin bileşiğinin bortriflorür dietileterat ile (BF3.OEt2) bazik ortamdaki reaksiyonu gerçekleştirilmiştir. Ortamın bazikliğini sağlamak için tri etil amin ( N(Et)3 ) yada tri etanol amin ( N(CH2CH2OH)3 ) kullanılmıştır.
Reaksiyonlar 80-90oC sıcaklıkları arasında gerçekleştirilip, reaksiyon süresinin değişkenliğinin eklenen bor triflorür dietileteratın ekivalentine bağlı olduğu görülmüştür. Kullanılan çözücününde reaksiyon üzerinde önemli etkisi olduğu görülmüştür. 
Özellikle ikili imin bileşiklerinin reaksiyonları tek imin bileşiklerine oranla daha yüksek sıcaklıklar gerektirdiğinden, reaksiyonlarında kaynama noktası yüksek olan 1,2-dikloroetan, kloroform gibi klorlu çözücüler kullanılmıştır.
Sentezlenen boranil bileşiklerin karakterizasyonu 1H-NMR ve 13C-NMR spektrometreleriyle gerçekleştirilmiştir. Boranil bileşiklerinin sahip olduğu optik ve elektirik özellikler UV-Vis ve Floresans spektroskopisiyle ölçülmüştür.
Elde edilen veriler ışığında sentezlenen çıkış maddelerinin ve bor komplekslerinin uygulama alanları hakkında araştırılma yapılmıştır.

Abstract:
Dyes having flourescence properties have been studied for many years by different research labs. BODIPY dyes and their family show interesting optical, electrical behavior that channel us to study on them.
Thanks to their properties that have been mentioned above, these dyes have been research subject at many applications. Such as; sensoring, DSSC, PDT.
Imine structure is essential to synthesize boranil derivatives which are family of BODIPY. Imine derivatives have been obtained by reaction between salicyl aldehyde and different primer amines. Also, symmetrical bis-imine derivatives have been synthesized by reaction between salicyl aldehyde and 4,4?-diaminomethylene, o-phenlyenediamine.
In this thesis, imine derivatives have been synthesized by reaction between salicyl aldehyde and o-phenylenediamine, benzidine, 2,4-dichloroaniline, 3-nitroaniline, ?-naphtylamine under acidic conditions. ( pH: 3-4 )
The yields of reactions are high and we realize that yields of bis-derivatives strictly dependent on solvent. Only one product is obtained and products are solid so that purification is easy and time-saving.
We have wanted to synthesize boron complexes ( Boranils ), as all imine derivatives have been supported by different spectral analysis.
To synthesize Boranil complexes, imine derivatives have been reacted with BF3.OEt2 under basic conditions.  N(Et)3  and  N(CH2CH2OH)3 have been used to provide basicity of reaction media. All reactions carried at 80-90oC , and we have seen that variability of reaction times depend on quantity of BF3.OEt2, and solvent has important effect on reaction process.
Especially, the reaction of bis-imine compounds need high temperature when compare with mono-imine compounds. Therefore, in the reaction of bis-imine compound, we have used 1,2-dichloroethane and chloroform as a solvent because of their high boiling points. 
Characterization of synthesized boranil complexes have been supported by 1H-NMR, 13C-NMR and FTIR spectroscopies, and optic properties of boranil complexes have been measured via UV-Vis and Spectrofluorometer spectroscopies.
On the basis of spectroscopic analysis, boranil complexes may be use in many application fields. The nature of fluorophore provide us some different properties explaining by PET and ICT. These two phenomena mostly have been act in sensoring and switching. PET ( Photoinduced Electron Transfer ) is an electron transfer which occurs when certain photo-active materials, in this case boranil complexes, interact with light. There are two type of PET processes. One is oxidative PET, the other is reductive PET. If the excited state of fluorescent group can accept electron from donating group, then the reductive PET occurs. However, if the excited state of fluorescent group can donate electrons to acceptor, then the oxidative PET occurs. Not being directly, solvent polarity has an effect on this process. When PET processes occur both ways, then the fluorescent  is diminished.
ICT ( Intramoleculer Charge Transfer )  is an association of two or more molecules, or of different parts of one very large molecule, in which a fraction of electronic charge is transferred between the molecular entities. In principle, ICT has been used to recognition of ions. If the molecule has electron donating group to fluorescent group, then molecule is not emissive. To alter emission properties,  donation blocker is introduced to molecule. Such as, if molecule has dimethylamino group close to fluorescent group, donation of dimethylamino can be blocked by introducing acid or complexation with metal ion. Therefore, nitrogen atom in dimethylamino group is charged, so electron donation can be blocked. When electron donation is blocked, positive charge on nitrogen atom can be transferred within the molecule causes increase of emission. In some cases this process occurs reverse.
There are many examples of  ICT and PET processes involved. Such as Hg+2 sensoring, Cu+2 sensoring, Zn+2 sensoring, CN- sensoring, F- sensoring, nitric oxide recognition and amine recognition.
As a benefit of fluorophore, besides of  recogniton and of sensoring, boranil complexes can be used as a light harvesting molecules and energy transfer cassettes.
In many occasions, energy transfer cassettes are used as biolabelling and monitoring. Energy transfer cassettes are supramolecular compounds having donor and acceptor sites that makes them tunable sensoring tool for labelling.
Light harvesting molecules can be simply explained as a molecule  having energy transfer between  donor and acceptor unit. Energy transfer can be taught as radiationless transition between two localized electronically states. If there is no energy transfer, dye molecule absorbs the light and give some emission. However, if there is a another dye which can be capable of absorbing first dye`s emissions. Then energy transfer occurs and acceptor dye ( unit ) make emission as fluorescence. In light harvesting molecules, energy transfer efficiency is dependent on many factors. Such as, strenght of donor and acceptor unit, spectral overlap between energy donor and energy acceptor, distance between donor and acceptor unit.
Energy transfer is accrued by two ways. First one is through bond ( Dexter Type Energy Transfer. ), second one is through space (FRET: Förster Resonance Energy Transfer.). 
Dexter type energy transfer requires orbital overlap between donor and acceptor by a bridge and the decay is exponantially depend on the distance.
Förster type energy transfer follows trough-space and does not require physical contact between donor and acceptor. The rate of energy transfer inversely depends on distance between donor and aceptor. The important conditions for efficient resonance energy transfer are a good overlap between fluorescence spectrum of donor with absorption spectrum of acceptor. This molecules can be used also molecular logic gates. Ion-induced photophysical phenomena yield signals varying in intensity and/or color, and when viewed from a different vantage point, these changes can be correlated with the binary response of Boolean logic gates. The photoinduced electron transfer (PET) is particularly appropriate for this purpose, because the changes observed by the modulation of the thermodynamics of PET with different inputs (analytes) usually yields "off-on" type, clear digital action. For two binary variables, there are 16 different types of Boolean functions, and molecular logic gates are available for most of them. There are considerable hurdles to overcome in reaching practically useful information processing at the molecular level, such as individual addressability and higher levels of integration, further refinement of functionally integrated combinatorial circuits is essential. It would be highly desirable to have arithmetic operators which produce the same kind of output with very sharp changes in the studied parameter. Fluorescence, being an essentially zero-background technique, has clear advantages as output. The changes in the emission spectrum can also be followed at more than one wavelength, resulting in more than one logic function in a single molecular or supramolecular system. This has been first demonstrated by us (vide supra) and then recognized as a powerful tool for obtaining multiple logic expressions. In the future, thanks to moleculer circuits, it may be possible to change traditional electronic circuits. 
In this thesis, our group is aimed to synthesize efficient tiny fluorophore which can be used in sensoring devices, energy transfer cassettes, light harvesting molecules.