Browsing by Subject "Boradiazaindacene"

Now showing 1 - 9 of 9

Open Access
Covalent self-assembly of an energy cascade in one step
(2015-08) Çamur, Ceren
Light harvesting mechanisms include absorption of energy by donor and transfer of the absorbed energy to acceptor. The aim of this process is the channeling of the light at certain wavelength. In this study, energy transfer process was sustained by BODIPY based Förster type light harvesting cascade. The donor and acceptor units of the cascade were synthesized to be combined by self-assembly. Passerini reaction was used in the assembly of the three units. Designed molecule consists of three moieties: BODIPY, monostyryl- BODIPY and distyryl-BODIPY. The expected process of energy transfer starts with the absorption of light at around 502 nm and ends with the emission at around 674 nm. The spectral overlap between donors and acceptors were shown. Under the light of the results, the designed molecule is promising to work as an effective energy transfer cascade.
Open Access
Covalently functionalized MSNs as potential photosensitizing agents for PDT
(2011) Türkşanlı Kaplan, Merve
Photodynamic therapy (PDT) is a novel approach for the treatment of some cancers and other non-malignant diseases. PDT aims to kill cancer tissue by the generation of singlet oxygen as a result of excitation of the photosensitizer (PS) by illuminating with a light source at a certain wavelength. Mesoporous silica nanoparticles are promising in PDT issue due to their chemical inertness, biocompatibility, lowtoxicity, hydrophility and ease of surface modification. We have synthesized and characterized novel boradiazaindacene (BODIPY)-based PS that is covalently attached to the pore of mesoporous silica nanoparticles (MSNs). We have observed that near infrared absorbing photosensitizer attached MSNs successfully generate cytotoxic singlet oxygen.
Open Access
Light harvesting and efficient energy transfer in boron dipyrrin dyads and derivatization for potential utility in dye-sensitized solar cells
(2008) Barın, Gökhan
In bichromophoric supramolecular systems light is harvested by antenna components and excitation energy is channeled into an acceptor component. We have designed and synthesized novel energy transfer cassettes which are based on boradiazaindacene (BODIPY) units. Facile synthesis of long wavelength absorbing distyryl BODIPY dyes has been applied successfully in this study. In the first part of the thesis, efficient energy transfer from energy donor BODIPYs to long wavelength absorbing distyryl BODIPY core was demonstrated. To observe the antenna effect quantitatively, we have designed the cassettes with an increasing number of energy donor components. Based on these observations, in the second part of the thesis, we have introduced a light-harvesting photosensitizer for dye-sensitized solar cell (DSSC) purposes. The target molecule absorbs in visible and near-IR region and energy transfer is demonstrated successfully. Our design appears to be highly promising for DSSC.
Open Access
Non-covalently functionalized SWNTs as potential delivery agents for novel BODIPY*based PDT sensitizers & the design and synthesis of dendritic light harvesters
(2009) Erbaş, Sündüs
Photodynamic therapy (PDT) is a non-invasive method used for the treatment of a number of diseases including certain cancers and some cardiovascular diseases. Photodynamic action depends on absorbance of photosensitizer (PS) in near IR region of the spectrum and subsequent generation of cytotoxic singlet oxygen in the vicinity of the PS. Carbon nanotubes are widely used for biomedical applications due to their inertness, biocompatibility, cellular internalization, facile and multi-modification. We have synthesized and characterized novel water soluble boradiazaindacene (BODIPY)-based PS, noncovalently attached on to the single wall carbon nanotube (SWNT). We have observed that near infrared absorbing photosensitizer preserve its singlet oxygen generation capability upon adsorption on SWNT. We have demonstrated that SWNTs can be used as the delivery vehicle of PS for the use in PDT. In the second part of this research, multichromatic cascade-type light harvesting BODIPY dendrimers were synthesized and highly efficient energy transfer was observed. Successful channeling of energy in a predefined region of the dendrimer was revealed.
Open Access
Novel near-ir photosensitizers for photodynamic therapy and designing heavy atom free photosensitizers for the photodynamic therapy
(2016-03) Kılıç, Bilal
Photodynamic therapy (PDT) is a promising and emerging noninvasive treatment modality for the treatment of a great number of malignant and non-malignant diseases. Therapeutic strategy in PDT is performed by combining a photosensitizer which can potently and specifically kill diseased cell and a light source, preferentially near-IR light (650-800 nm). In spite of the fact that numerous studies have been published and notable progress has been made in tumor biology and photochemistry which let us to design novel therapeutic agents, the number of the new therapeutic agents which have been recently got approval for clinical application are relatively low. We aimed to produce novel photosensitizers. In the chapters 3, 4 and 5 BODIPY dyes which are amenable to functionalization have been used to produce a novel series of BODIPY-based photosensitizers. We synthesized and characterized a series of novel BODIPY-based photosensitizers. The first part describes novel near-IR BODIPY-based photosensitizers. In the second part, the main goal was to design and synthesize heavy atom free BODIPY-based photosensitizers. In this respect, a new modification of the BODIPY dyes, novel orthogonal BODIPYs were synthesized and their computational analysis were done. A cell culture assay with cancer cell lines was performed in order to demonstrate photocytotoxicity of the orthogonal BODIPY. The third study underlines the importance of micelle-embedded BODIPY-based photosensitizers for photodynamic therapy.
Open Access
Phenylethynyl-BODIPY oligomers: bright dyes and fluorescent building blocks
(2009) Cakmak, Y.; Akkaya, E. U.
Boradiazaindacene dyes were converted into phenylethynyl-BODIPY oligomers via a cycle of reactions, notably including Sonogashira couplings. As expected, as the number, n, of repeating units increases, peak absorption and emission wavelengths are shifted to the red end of the visible spectrum, albeit with smaller increments as n increases. Decyl groups help to keep the solubility remarkably high, and in addition to being very bright red-emitting fluorophores, their rigid rod-like structures could allow their use as functional building blocks. © 2009 American Chemical Society.
Open Access
Rational design of two photon absorbing Bodipy dyes
(2010) Kılıç, Bilal
Two photon absorption is a nonlinear process which is of particular interest in various applications such as optical data storage, fluorescence imaging, O2 sensing and photodynamic therapy. These applications have created a strong demand for new dyes which have high two photon absorption cross section. In the two- photon absorption process there is an interaction of the two photons which are simultaneously absorbed by materials. For this purpose, we have designed and synthesized a novel class of distyryl-substituted boradiazaindacene (BODIPY) dyes which absorb two one photon in the green or two photons in the near IR regions of the (electromagnetic) spectrum and have D-A-D structure. As expected, as the strength of the donor groups which were introduced to the 3,5 position of the BODIPY core increase, absorption and emission maxima of the BODIPY dyes are shifted in the near IR regions of the spectrum. Furthermore, GM values increase due to the enhancement donor strength of the terminal groups. In summary, we have successfully synthesized a novel class of BODIPY derivatives which have large TPA cross section values.
Open Access
Solid state emissive bodipy dyes with bulky substituents as spacers and a sensitive and selective ratiometric near IR fluorescent probe for zinc ions based on the distyryl-bodipy fluorophore
(2010) Özdemir, Tuğba
Dyes having solid state fluorescence are playing an important role for organic light emitting devices (OLED), optoelectronic devices and photoelectric conversion. However, emissive solids are not common because of the quenching resulting from the packing. With these considerations, we have synthesized and characterized novel boradiazaindacene BODIPY-based dye with bulky substituents (3,5-di-tert-butylphenyl) to prevent π-π stacking of the chromophore. We have succesfully demonstrated that by simple modulation of BODIPY core with very bulky groups lead us to have a bright emissive compounds in solid state. In the second part of this research, we developed BODIPY based near-IR dye as a selective, ratiometric and water-soluble fluorophore for Zn (II) cation. We functionalized the versatile BODIPY from its 3 and 5 positions for long wavelength emission the zinc selective chemosensor.
Open Access
Synthesis and characterization of near-ir emissive tetra styryl-BODIPY based light harvesting energy transfer cassettes
(2011) Köstereli, Ziya
Light harvesting antenna systems are being used to harvest light through its antenna units. Using these systems, light is channeled into an acceptor chromophore and much more concentrated energy is obtained in acceptor unit with a specific wavelength. In this study, we have rationally designed and synthesized two different novel Förster-type light harvesting energy transfer cassettes which have large stokes shifts and emit in near-IR region. The first cassette has four boradiazaindacene (BODIPY) as donor groups and one tetrastyryl-BODIPY as an acceptor group. The second cassette has four distyryl-BODIPY units as donor groups and one tetrastyryl-BODIPY as an acceptor group. Click chemistry is successfully used to combine donor and acceptor groups to each other. Efficient energy transfer from donor groups to acceptor group in both cassettes was observed and characterized using emission spectrum, quantum yields and lifetimes. Energy transfer efficiencies and rate of energy transfer were calculated and it is demonstrated that there is more efficient energy transfer in cassette that has better overlap in donor emission and acceptor absorption spectrum which is in accordiance with expected behaviour for Förster-type of energy transfer cassettes.