Theses supervised by Huriye İcil
23 theses · Eastern Mediterranean University
The Synthesis of Novel Comb Shaped and Chiral Amphiphilic Polymers
In recent years, intensive research efforts have been committed to studying Am-phiphilic polymers, particularly in the pharmaceutical applications. These polymers have ability to form a different macromolecular architecture in the aqueous solution such as polymeric micelles. Novel combshaped, chiral and fluorescent amphiphilic polymers are important for pharmaceutical applications including hydrophobic drug solubilization. In this thesis, four chiral, combshaped and fluorescent novel amphiphilic polymers were synthesized from chitosan and perylene diimide. The compounds were analyzed using FTIR, UV-vis and Emission spectroscopy.
Novel Core-Expanded Perylene Diimide Dye: Synthesis, Characterization and Optical Properties
Perylene molecules bearing two aryloxy substituents on bay position (1,7 positions) and two receptor units at the imide positions are most useful fluorescent building blocks for the realization of a broad variety of self-assembly architectures. High absorption of perylene diimides (PDIs) in the visible region offers many advantages for photonic applications, optimum electron transport properties, flexible synthetic potentials to adjust energy levels, solubility, stacking properties, excellent thermal and photo-stability. In this thesis, a novel perylene diimide with tyramine substitution at the bay (1,7-position) and imide position was designed and synthesized successfully. The synthesized product was characterized by FTIR, UV-vis, emission, TGA, DSC techniques and elemental analysis. The photophysical and thermal properties of Ty-B-PDI reveal that it as a good candidate for photovoltaic applications.
Synthesis, characterization and spectroscopic properties of chiral perylene 3, 4 -dicarboxylic- 9, 10- ((R) - (+) - 1 - Phenylethyl) - carboximide for solar cell applications
Perylene chromophoric derivatives are versatile compounds for many applications in various fields. Excellent optical properties such as high extinction coefficients and strong fluorescence combined with ease in electron accepting ability are most notable advantages of perylene derivatives. Herein, the project focused on the synthesis of different kinds of perylene dyes, a chiral perylene diimide, a chiral perylene monoimide, and a perylene dicarboxylic acid chiral monoimide, named, N,N′-bis((R)-(+)-1-phenylethyl)-3,4,9,10-perylenebis(dicarboximide) (PDI), N-((R)-(+)-1-phenylethyl)-3,4,9,10-perylenetetracarboxylic-3,4-anhydride-9,10-imide (PMI), chiral perylene-3,4-dicarboxylic -9,10-((R)-1-phenylethyl)carboximide (CPMI), respectively. The final perylene derivative CPMI was synthesized in three consecutive reactions. CPMI was especially designed to be applicable in photovoltaic cells such as dye sensitized solar cells. The synthesized perylene derivatives are characterized in detail by investigating their optical, photophysical, and thermal properties using the techniques FTIR, UV-vis, Fluorescence, DSC, TGA and elemental analysis. They exhibited interesting optical properties, high solubilities, high molar absorption coefficients, and thermal stabilities. Keywords: perylene diimide, perylene monoimide, carboxylic acid monoimde, chiral, extinction coefficient.
Synthesis and Optical properties of New Perylene Derivatives
Versatile substituents of perylene chrmophores creates higher absorptions in visible region of absorption spectrum and also exhibits higher coefficients of molar extinction. Furthermore, they have the ability to emit light of almost unitary which signifies higher fluorescence quantum yields. Perylene dyes acts a major role in dye sensitized solar cells due to the presence of four carbonyl groups in its core which creates ease of accepting an electron. In this research, N,N′-Bis(3,3,5,5-tetramethyl-4-piperidinyl)-3,4,9,10-perylenebis (dicarboximide) (PPDI) and N-(3,3,5,5-tetramethyl-4-piperidinyl)-3,4,9,10-perylenetetracarboxylic-3,4-anhydride-9,10-imide (PPMI) were sensitized and comparison of their photophysical properties were carried out. FTIR spectroscopy was used to characterize the compounds and their photophysical properties analyzed via absorption and emission spectroscopy. All the perylene dyes synthesized showed very high molar absorptivity with the highest being 152000 M-1cm-1 obtained from PPMI. PPMI absorption spectrum shows a 4 nm blue shift in a polar aprotic solvent as a result of increased level of polarity and the stabilization of PPMI energy levels it induces on the structure. Keywords: Perylene diimide, perylene tetracarboxylic acid, perylene monoimde, perylene carboxylic acid monoimide.
Synthesis and Characterization of p-Type Poly(2,7-carbazole) Materials for Solar Cells
π-Conjugated light emitting polymers are having very wide applications in many areas, especially in optoelectronic, photonic and renewable energy systems. 2,7-substituted polycarbazoles are excellent p-type candidates with great potential toward these applications. However, very few reports were published in literature about the applicability of poly(2,7-carbazoles) which is attributed to the difficulties in direct functionality at 2,7-positions (meta-). In the present work, we report the synthesis of a 2,7-dibromo-substituted polycarbazole (poly(N-dodecylcarbazole)-2,7-diyl) material via four different consecutive steps. In first two steps, the basic 2,7-substitution was made by using commercial dibromobiphenyl and then the monomeric dodecylcarbazole was synthesized by nucleophilic substitution in the third step. Finally, the titled polymer was synthesized by Yamamoto polymerization. The structures of the intermediate products are confirmed by FTIR. The monomer and polymer were characterized by FTIR, UV-vis, emission and NMR techniques. The polymer has shown broad absorption comparing to the parent 2,7-dibromo-substituted-carbazole and monomeric dodecylcarbazole. Similarly, PCbz has exhibited strong excimer emission in all of the most commonly used organic solvents. Nevertheless, owing to the attractive tunable optical properties poly(2,7-carbazoles) and derivatives, they could be used as smart materials for electroactive and photonic device architectures. Keywords: Carbazole, Dodecylcarbazole, Poly(dodecylcarbazole), Excimer
A Novel Perylene Polymer Based on the 1,3,5-Triazines
Perylene chromophore containing supramolecular chromogenic polymers represent an important research topic relating to its interesting optoelectronic and redox properties. In the present study, a novel chromogenic polymer (TAPPI) was synthesized by polycondensation of perylene-3,4,9,10-tetracarboxylic dianhydride (PDA) with hindered aromatic diamine, 2,4-diamino-6-phenyl-1,3,5-triazine in isoquinoline and m-cresol solvents mixture under argon atmosphere. The synthesized product purity was confirmed using elemental analysis, IR and UV-vis spectroscopy. The product TAPDI is soluble mainly in polar solvents such as pyridine, NMP, DMF, DMSO, m-cresol in purple and TFAc pink colours. It is important to note that, different absorption and emission properties have been observed due to different intermolecular interactions in various solvents. The lower fluorescence quantum yield of the TAPPI in NMP, DMF and DMSO solvents (70%, 60% and 30%) could be attributed to conformational changes, torsional movement, or other non-radiative decays. Overall, the new polymer TAPPI has shown great potential for further photonic technology. Keywords: Perylene polymers, hindered diamine, photonics, solar cells.
Synthesis and Characterization of A New Electron Acceptor Perylene Diimide for Further Functionalization
Nowadays, novel organic substances are broadly employed in numerous sensing architectures. Clever organic compounds with profound electrochemical and photophysical properties are important for photonic applications. Importantly, electron acceptor properties of perylene derivatives are well known. In the present project, a new perylene bisimide named as N,N′-Bis(2-(4-hydroxyphenyl)ethyl)-3,4,9,10-perylenebis(dicarboximide) (HE-PDI) has been successfully synthesized. The synthesized HE-PDI was characterized by FT-IR and its photophysical properties were studied by UV–vis absorption and emission spectroscopy techniques. HE-PDI has high extinction coefficient and fluorescence quantum yield (Φf = 0.91). The synthesized HE-PDI is completely soluble in the both dipolar aprotic (DMF, DMSO, etc.) and non-polar solvents like (CHL). Keyword: Perlyene bisimide, Electron acceptor, Fluorescence quantum yield, thermal stability
New Perylene Diimide Dye Synthesis Containing Powerful Binding Sites For Metal Ions
Metal binding is expected to make changes in photophysical and photochemical properties of sensitizers such as wavelength shifts and intensity changes in absorption and emission spectra. Perylene chromophoric dyes are excellent materials of aromatic π-conjugated heterocyclic family. The rigid structure of perylene chromophores causes strong intermolecular π-π interactions giving rise to versatile optical and electronic characteristics. With the advantages of tailoring the imide and bay-positions of perylene structures, exclusive benefits were achieved such as n-type semiconducting character, extended absorption coefficients, high photoluminescence quantum yields, self-assembly behaviours, thermal and photostabilities. A new perylene diimide dye containing powerful binding site for metal ions was synthesized successfully. The synthesized product was characterized by FTIR, UV-vis, emission, TGA, DSC and elemental analysis. In addition, the photophysical properties were investigated in detail. The high thermal and photostabilities, including important photonic properties, make the new dye a potential candidate for various photo-sensing applications.
Synthesis and Characterization of a New Perylene Anhydride Derivative Functionalized at the Bay Region
Perylene chromophore has an outstanding aromatic conjugation. The functionalization at the bay and imide positions brings great advantages. Specifically, functionalization at the bay region via long alkyl chain improves the solubility as well as the optical and electrochemical properties. In this thesis study, we have synthesized a new bay-substituted perylene dianhydride, (1,7-di(2-decyl-1-tetradecanoyl)-perylene-3,4,9,10-tetracarboxylic dianhydride; decanol-PDA) in two steps. In the first step, the bay positions (1, 7-positions) of perylene dianhydride (PDA) were brominated (Br-PDA). In the second step, the targeted bay substituted perylene dianhydride (decanol-PDA) was synthesized through bay substitution of perylene core with 2-decyl-1-tetradecanol. The product was purified and characterized by using FTIR spectroscopy, UV-vis spectroscopy and emission spectroscopy. Expectively, the synthesized product showed enhanced solubility comparing perylene anhydride. The UV-vis absorption spectra of the two synthesized perylene derivatives in nonpolar solvents showed three characteristic absorption bands, that are belonging to π–π* electronic transitions of perylene chromophore. While, the UV-vis absorption spectra in dipolar aprotic solvents showed additional absorption bands at higher wavelength. The emission spectra of the synthesized compounds showed excimer-like emission spectra in nonpolar and dipolar aprotic solvent. Keywords: Perylene dianhydride, bay-substitution, optical and photophysical properties.
Electron Donating 2,7-Carbazole Derivatives: Synthesis and Characterization
Carbazoles (Cbz)s are well known electron-donating materials because of the conjugated π-electrons present in their structures, they are one of the most suitable candidates for construction of electronic devices. In the present work, we synthesized a 2,7-dibromo-N-dodecyl carbazole (dodecylcbz) via a two step procedure. In the first step, 2,7-dibromocarbazole (cbz) was synthesized (via another two step procedure–nitration of dibromobiphenyl and consequent cadogan ring closing steps). In the second step, the targeted dodecylcbz was synthesized via nucleophilic substitution. The synthesized compounds were characterized by mp, FTIR, UV-vis, NMR, and emission techniques. The FTIR spectra confirm the structures. The solubility is very high for both the cbz and dodecylcbz in all common organic solvents. The absorption spectra of both cbz and dodecylcbz show high energy forbidden S0→S2 transition absorptions with high intensity at around 240 nm comparing to π→π* electronic transition absorptions at around 303 nm, respectively in all of the common organic solvents studied. Most importantly, π→π* electronic transition absorptions of both carbazole and dodecylcarbazole were unchanged with respect to the polarity and type of the solvent. Whereas, S0→S2 transition absorptions have undergone solvent-dependent shifts. Both the cbz and dodecylcarbazole exhibited intense excimer emissions in all of the solvents. These interesting optical properties are very useful for present-day organic-based optoelectronic applications. Keywords: Carbazole, 2,7-Dibromocarbazole, Excimer Emission, Forbidden Transitions
Synthesis, Characterization and Optical Properties of a Bay- Functionalized Perylene Dye:N, N′-Didodecyl-1,7-di(3-methylphenoxy)- perylene-3,4:9,10-tetracarboxylic Acid Bisimide
Perylene chromophore has an excellent aromatic conjugation and offers numerous advantages in many fields of application. One of their greatest advantages is the capability to functionalize the chromophore at its core/bay and imide positions with various substituents according to the desired application. In the present research on perylene dyes, we have synthesized a new core substituted perylene diimide in three consecutive steps focusing the application toward solar cells. Firstly, the starting raw material perylene dianhydride was brominated at 1,7- positions of the perylene chromophore to yield brominated dianhydride (Br–PDA). The product was imidized in the second step with a long dodecyl alkyl chain to yield brominated perylene diimide (Br-PDI). Finally, the targeted core substituted perylene diimide (PDI-m-Cresol) was synthesized upon bay substitution of perylene chromophore with m-cresol. The final compound is highly pure and characterized by FTIR, UV-vis and Emission measurements. For comparison, photophysics of the intermediate products were carried out in parallel. The absorption spectra of three perylene derivatives in nonpolar aprotic solvents and polar protic solvents show characteristic aromatic π–π* transition absorption peaks. In contrary, absorption in dipolar aprotic solvents shows irregular additional absorption bands (Br-PDA in NMP; Br-PDI in DMF; and PDI-m-Cresol in DMF and NMP) at higher wavelengths which were remained after microfiltering the solution. Interestingly, the emission spectra of the three perylene derivatives have shown traditional three characteristic emission peaks and were not influenced by additional weak absorption bands. Keywords: Perylene dyes, perylene derivatives, Bay-substitution, characterization of perylene derivatives.
Naphthalene Diimide For Selective Telomeric G-Quadruplexes: Synthesis And Characterization
Nowadays, as a result of developing new technologies, the applications of organic substances utilized in various fields are growing interest. The naphthalene diimides, due to their excellent electrochemical, thermal and photophysical properties as well as their excellent light emitting potentials have been intensively investigated as electronic materials in photonic applications. In addition, naphthalene diimides are used as potential ligands in biological applications, especially in DNA binding. In this research, N,N'-bis(2-(4-hydroxyphenyl)ethyl)-1,4,5,8-naphthalenediimide (HE-NDI) has been synthesized successfully. The structure of product was characterized and investigated by optical and photophysical properties using FT-IR, UV-vis and emission spectroscopic techniques. The HE-NDI has shown high molar absorptivity and fluorescence quantum yield. The results have pointed that the HE-NDI is a potential candidate for photonic application and DNA binding. Keyword: Naphthalene diimide, Solar cell, Photovoltaic, DNA
Synthesis and Characterization of Novel Bay-Substituted Perylene Dyes for Dye-Sensitized Solar Cells
Nowadays the development and fabrication of Perylene dyes with suitable absorption and improved mechanical and electrical properties are widely investigated. The purpose of the present studies were focused to synthesize the high soluble perylene diimides, easy processable and good photonic properties. Substitution of perylene diimides in bay position causes a remarkable increase in optical, electronic properties, solubility, the more red shifted absorption band, good molar absorptivity and thermal stability. In the first section nano silica, nanosilica sulfunic acid (NSSA), were synthesized, also different parameters which is thought to have influence on the size of synthesized nanosilica particles were studied. In the next section of this research, first step was Bay-substitution Bromination of Perylene dianhydide, then some sorts of bay substituted perylene-diimides consist of N,Nˊ-Di(phenoxy)-1,7-diphenoxyperylene-3,4,9,10-perylenetetracarboxy-diimide (BP-PPI), N,Nˊ-Di(dodecyl)-1,7-di-3-amino-9-ethylcarbazol-perylene-3,4,9,10-perylenetetracarboxy-diimide (BC-PDD), 1, 7-(diphenoxyperylene perylene-3, 4:9, 10-tetracarboxylic acid dicarboximide)-3,4:9,10-tetracarboxylic anhydride (BPDA-PDA), N,N׳-Didehyoebiethyl-1,7-di(N`-dehyoebiethyl,N-phenoxy) perylene-3,4,9,10-tetracarboxylic acid diimide) perylene-3,4,9,10-tetracarboxylic acid diimide (BPDI-PDI), N,Nˊ-bis(3-triethoxysilylpropyl)-1,7-di-phenoxyperylene-3,4:9,10-tetra-caboxdiimide (BP-PDISi) also its nano-bay substituted alkoxysilane-functionalized perylenediimide (PDI) by using 3-amino-propyl triethoxysilane (APTES) were synthesized. Finally Poly-N,Nˊ-bis(3-triethoxysilylpropyl)-1,7-di-phenoxyperylene-3,4:9,10-tetra-caboxdiimide (BP-PPDISi) and Nanosilica-N, N-bis((S)-(−)-1- phenylethyl)-3,4,9,10-perylene (NSPDI), with fluorescence emission in the near infrared (NIR) were synthesized by sol-gel method, also the effects of different parameters on particle size has been studied. The compounds were characterized by FT-IR, Elemental analysis, CNMR, HNMR, UV-visible, Fluorescence, TGA thermogram, DSC, SEM, TEM and AFM techniques. Keywords: perylene, bay substitution, macromolecule, nanoperylene.
Synthesis and Properties of Donor-Acceptor Conjugated Macromolecules as N-Type Semiconductor for Organic Solar Cells
The fabrication of novel molecular dyes with suitable absorptive properties for photon harvesting is an essential area to search on for efficient photovoltaic cells. Perylene diimides show vibronic absorption band at the middle of visible region of solar irradiation. Introduction of substituents onto the perylene bay region usually perturbs the orbital energy of the perylene π-π intermolecular system which eventually leads to shifting of the absorption maximum to longer wavelength. In this thesis, the electrochemical properties of chiral multichromophoric macromolecule (NPM) and its components were well studied. NPM exhibited low band gap energies of 2.25 V and 1.7 V in solution and solid-state, respectively. Also, three novel macromolecular bay-substituted perylene diimides have been synthesized successfully and photophsically characterized namely, N,N'-Di(dodecyl)-1,7- diphenoxylperylene-3,4,9,10-tetracarboxy diimide (BP-PDD), N,N'-Di(5-amino-3- pyrimidinethiol)-1,7-diphenoxyperylene-3,4,9,10-tetracarboxy diimide (BP-PPD) and N,N'-Di(2,2,4(2,4,4)-trimethyl-6-aminohexyl))-1,7-di(1-amino-4- ethanolpiperidyl)perylene-3,4,9,10-diimide (TPE-PDI). All the synthesized compounds possess appreciable longer wavelength comparing them with their parent perylene diimides with good solubility in several organic solvents. These compounds were characterized in detail by several techniques such as NMR, FT-IR, Elemental analysis; UV-visible, Fluorescence, TGA thermogram, DSC and the results were analyzed. These results showed an asset for construction of photovoltaic devices such as organic solar cells. Keywords: Perylene, bay-substitution, absorptivity, macromolecule, solar cell
Electron Accepting Perylene Dyes with Versatile Imide Substituents: Synthesis and Characterization
Perylene bisimides (PBIs) have received significant attention due to their exceptional photophysical and optical properties. Derivatives of PBIs show high fluorescence quantum yields, high electron affinities and large band-gaps‚ that make them excellent candidates for numerous optoelectronic devices such as light-emitting diodes, photovoltaics, optical switching, and electroluminescent devices. PBIs are considered as n-type semiconductors in which the main charge carriers are in their conduction band. On the other hand, most organic conducting substances are p-type semiconductors. In the current work, the synthesis of a new perylene bisimide N‚N′-Bis(1-methyl-2-cyanoethene)-3,4,9,10-perylenebis(dicarboxiimide) (EAPDI) was carried out. 1-methyl-2-cyanoethene substituent is specifically chosen so that the imide regions of perylene core offer better solubility and impressive optical properties of the perylene bisimide. The synthesized bisimide was approved by FT-IR and its photo-physical properties were studied by UV–vis and emission techniques. EAPDI has high molar absorptivity as well as high fluorescence quantum yields (Φf = 0.72). The absorption and emission spectra of EAPDI are mirrored images in DMF, CHCl3, MeOH with smaller Stoke shifts. Keywords: Perylene bisimide, 1-methyl-2-cyanoethene, absorbance, fluorescence.
A New Perylene Monoimide Derivative as Potential DNABinding Agent
Nowadays, inhibiting telomerase and consequent disruption of the telomeres via formation of small organic molecule based G-quadruplex DNA structures is extensively studied. The potential of curing cancer cells (preventing the replication) by the formation of G-quadruplexes is emerging as an efficient method. π-Conjugated perylene dyes are one of the most suitable small organic molecules that can bind to DNA to form G-quadruplexes. In the present research work, two perylene dyes, namely, aminododecyl perylene diimide (ADPDI) and aminododecyl perylene monoimide (ADPMI) were synthesized in order to explore their potential towards DNA binding. Especially, long alkyl chain attached amino groups have been induced at the imide positions of the perylene chromophore to increase the capacity of hydrogen bonding. The synthesized ADPDI and ADPMI dyes have been characterized via TLC, FTIR, UV-vis, and emission measurements. FTIR spectra support the structure of the dyes. UV-vis absorption spectra in dipolar aprotic DMF (for ADPMI) and nonpolar isoquinoline (for ADPDI and ADPMI) solvents show that the dyes are aggregated to some extent in solutions by forming a broad absorption shoulder in their absorption spectra. Keywords: Perylene diimide, Perylene monoimide, G-quadruplex, DNA binding
Synthesis and Properties of Low Band Gap Organic Semiconductors for Solar Cell Applications
The development of new PV technology is essential with increasing consumption of fossil fuels and seems to be the only way to cover energy demand. The primary objective should be accomplished efficiency between cost and power conversion efficiency. Moreover, the applicability of new materials is primarily determined by their balanced electrical, thermal, physical and chemical properties. In this thesis, a new series of low band gap aromatic polyimides were successfully synthesized to be used in photovoltaic applications as next generation organic semiconductor material. To this purpose, chitosan biopolymer based two aromatic polyimide functionalized with commercially available perylene and naphthalene organic semiconductors and previously synthesized high molecular weight naphthalene based polyimide have been characterized in detail by studying their , photophysical, thermal and electrochemical properties through the data obtained from NMR, FTIR, GPC, UV-vis, Fluorescence, DSC, TGA and CV and SQWV. Incorporation of the hydrophobic chromophore units within the hydrophilic polymeric backbones yielded a network-like structure and maintained good solubility. The compounds showed extraordinary thermal stabilities and high molar absorption coefficients. They possessed excimer type emission and aggregation formation which confirmed the electroactive species both in ground and excited state. The products showed outstanding electrochemical stability and also undergoes only one reversible reduction and oxidation in solid state which make them candidate as Donor/Acceptor polymer for PV technology. Keywords: Perylene, Naphthalene, Donor/Acceptor Polymer, High Molar Absorptivity
Energy Transfer Studies of Electron Donating Carbazole and Electron Accepting Perylene Dye Systems
Electron donating poly(2,7-carbazoles) are one of the most attractive materials emerged as p-type semiconductors for applications in photovoltaic devices in combination with relevant electron accepting systems. On the other hand, perylene dyes are known as versatile n-type building block materials for organic device architectures and supramolecular systems. These polymeric- or small molecule-based organic materials are very important concerning controlled and improved light emission is therefore a key issue and blending of fluorescent dye materials with conjugated polymers could enhance transfer of energy (excitation) from host to guest. In the present work, the electronic energy transfer between three different chromophoric materials of 2,7-carbazoles and perylene dyes were investigated. The carbazole compounds are considered as electron donors and perylene diimide is considered as electron accepting group. The energy transfer studies of three carbazole derivatives with perylene dye in three different kinds of varying polarity (CHCl3, 4.81; CH3CN, 37.5; CH3OH, 32.6) reveal that most efficiency is achieved for the three of the carbazoles in CHCl3. The critical transfer distances measured are in excellent agreement and in addition Stern-Volmer plots show efficient diffusion-controlled energy transfer in chloroform. Although there is no efficient nonradiative energy transfer in CH3CN and CH3OH, interesting charge transfer leading to electron transfer are evidenced from carbazole to perylene chromophore Keywords: Energy Transfer, Stern-Volmer, Carbazole, Perylene
Synthesis of A New Perylene Derivative Ligand Potential for DNA Binding
The main aim of this project was the synthesis of a novel perylene compound, named, N-(1-dehydroabietyl)-3,4,9,10-perylenetetracarboxylic-3,4-anhydride-9,10-imide (ABPMI), from N-N’-di(1-dehydroabietyl)perylene-3,4,9,10-bis(dicarboxymide) (ABPDI ) for future DNA binding studies. The product was characterized by FT-IR, UV-vis and emission spectrometry. The optical and photophysical properties have been investigated in detail. ABPMI showed moderate solubility in some common organic solvents like chloroform, DMF and methanol. In the UV-vis absorption spectra of ABPMI in chloroform and methanol three characteristic peaks have been observed at 439, 469 and 517 nm, respectively (with small red shift in methanol). In absorption spectrum of ABPMI in DMF, three peaks have been achieved at 439, 465 and 518 nm, with the reversal intensity between 0→0 and 0→1 transition. In emission spectra of ABPMI in chloroform, DMF and methanol, excimer-like peaks have been observed. The optical band gap energy of ABPMI has been calculated as 1.984 eV. The synthesized compound is promising as a potential ligand for future DNA binding studies. Keywords: Perylene diimide, Perylene monoimide, Perylene dye
A Novel Naphthalene Polymer Based on the 1, 3, 5 -Triazines
Naphthalene diimide-based polymers used as acceptors in organic photovoltaic cells due to their perfect thermal, chemical, and photochemical stability and high electron affinity. In the present study, a novel naphthalene polymer (TANPI) was synthesized by polycondensation of 1,4,5,8-naphthalene tetracarboxylic dianhydride (NDA) with hindered aromatic diamine, 2,4-diamino-6-phenyl-1,3,5-triazine in isoquinoline and m-cresol solvents mixture and under argon atmosphere. The synthesized product purity was confirmed using elemental analysis, IR and UV-vis spectroscopy. The product TANPI is soluble mainly in polar solvents such as pyridine, NMP, DMF, DMSO, m-cresol and TFAC in brown colour. The product was insoluble in polar protic solvents such ethanol and methanol. The optical properties for the polymer were investigated using absorption and emission spectrophotometric measurements. Observed different properties indicate different intermolecular interactions in different solvent which can be important in photonic applications. It is important to note that, excimer emission were observed in pyridine, NMP, DMF, DMSO, m-cresol and TFAC with long Stoke Shifts. Fluorescence quantum yields in different solvents were determined using anthracene in ethanol as standard (NMP: 2%, DMF: 5% and DMSO: 1%). Keywords: Naphthalene polymers, hindered diamine, photonics, solar cells.
A Comparison of Photophysical Properties of A Chiral Perylene Monoimide with 3,4,9,10-Perylenetetracarboxylic Acid
The perylene chromophore with versatile substituents offers strong absorption in the visible region with high molar extinction coefficients. Moreover, they are capable of emitting light with high fluorescence quantum yields near unity. The four carbonyl groups present in the core structure facilitate ease of accepting electrons and therefore perylene dyes plays important role for dye sensitized solar cells. In this project, perylene -3,4,9,10 tetracarboxylic acid (PTCA) and perylene-3,4-dicarboxylic-9,10-(R)(+)1phenylethyl)-carboximide (R-CPMI) were synthesized and their photophysical properties were compared. The synthesized compounds were characterized by FT-IR spectroscopy and photophysical properties were studied by absorption and emission spectroscopy. All the synthesized dyes have very high molar absorptivities. The highest value is obtained for R-CPMI 114000 M−1 cm−1. PTCA and PDA absorption spectra indicate aggregation formation where dye-dye molecular interaction in PTCA is higher than PDA. Introducing a chiral substituent at one end of the PTCA breaks dye-dye molecular interaction in polar aprotic solvents. R-CPMI absorption spectrum in polar protic solvent display 9 nm blue shift due to hydrogen bonding. Keywords: Perylene diimide, perylene monoimide, perylene carboxylic acid monoimide, perylene tetracarboxylic acid
Synthesis, Characterization and Optical Properties of a Bay-Substituted Perylene Dye: N,N′-Didodecyl-1,7-di(2-Decyl-1-tetradecanoyl)- perylene-3,4:9,10-tetracarboxylic Acid Bisimide
Functionalization of perylene chromophore to result in a wide variety of perylene derivatives is a renowned strategy. Functionalization can be achieved by the substitution of corresponding groups at bay and imide positions of the conjugated aromatic perylene chromophore. In the current work, we have synthesized a new bay–substituted perylene diimide in three steps. We have selected the long aliphatic and branched aliphatic chains to substitute at imide and bay- positions, respectively, to promote the solubility as well as the electrical and optical characteristics. In the first step the raw compound perylene dianhydride was brominated at 1,7-positions of the perylene chromophore to result in brominated dianhydride (BrPDA). Subsequently, BrPDA was imidized at the imide positions of BrPDA with dodecyl amine to yield brominated perylene diimide (BrPDI). In the final step, the designed bay-substituted perylene diimide (PDI-Decanol) was synthesized upon substituting 2-decyl-1-tetradecanol at the bay positions of perylene core. The final compound was purified and the resulting PDI-Decanol was characterized by FTIR, UV-vis and fluorescence measurements. A detailed comparison on optical properties was made especially by studying the photophysics of the intermediate products along with the PDI-Decanol. The UV-vis absorption spectra of the three synthesized perylene derivatives in nonpolar aprotic solvents show regular characteristic π–π* absorption bands. Contrarily, absorption in dipolar aprotic solvents shows weak additional absorption bands (BrPDA in NMP; BrPDI in DMF; and PDI-Decanol in DMF and NMP; and iv methanol) at higher wavelengths which were remained after microfiltering the solution. Interestingly, the emission spectra of the three perylene derivatives have shown traditional three characteristic emission peaks and were not influenced by additional weak absorption bands. Keywords: Perylene, bay-substitution, brominated dianhydride, brominated diimide, aliphatic substituent.
New Naphthalene Diimide Dye Synthesis Containing Powerful Binding Sites for Metal Ions
Naphthalene diimides (NDI) are a class of organic dyes with optical, thermal, and photochemical properties and stability. Hence, its importance in the rapidly developing modern technology, have found expression amongst researchers. NDI interaction with metals is expected to make change in photophysical and photochemical properties of sensitizers such as wavelength shifts and intensity changes in absorption and emission spectra. Consequently, metal complexation of NDI leads to high potential towards organic electronic application. The synthesized compound exhibit different intermolecular interactions in different solvents which enhances its utilization in photonic and optoelectronic application. Therefore, this project aims to synthesize a new NDI dye containing powerful binding site for metal ions. By condensation reaction, NDA and an amine (4,6-diamino-2- pyrimidine-thiol) reacts with isoquinoline and m-cresol solvent mixture in the presence of argon gas. The synthesized product was investigated by IR and UV-vis spectroscopy, TGA and DSC analysis for thermal behavior and elemental analysis. Keywords: Naphthalene diimides.