Comparison of donor-acceptor-donor type conjugated systems with cross-exchange of donor units

Download

12625979.pdf

Date

2020-11-23

Author

Eroğlu, Deniz

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

197
views

234
downloads

In this thesis study, a series of new donor-acceptor donor type monomers were synthesized. For this purpose,benzothiadiazole (B) was used as the acceptor unit. Donor units, carbazole (C) and thiophene(T), were combined to B unit both symmetrically (CBCand CTBTC) and unsymmetrically (CBT) to understand the effect of cross exchange of donor units on the opto-electronic properties of monomers.The monomers were characterized using Nuclear Magnetic Resonance (NMR) and High-Resolution Mass (HRMS) spectroscopies. Optical properties of monomers were investigated by using UV-visible and fluorescence spectroscopy. Replacing oneof the symmetrical carbazole units in CBCmonomer with thiophene unit results in about 8 nm red shift in optical absorption. Having both carbazole and thiophene units symmetrically in the monomer structure increases the conjugation and exhibits about 70 nm red shift in the optical absorption.On the other, electrochemical behaviour of monomers were investigated utilizing cyclic and differential pulse voltammetry techniques. As a result of these studies, CTBTCmonomer was found to have the lowest oxidation potential and it has the lowest band gap energy (both optical and electronic) due to increased conjugation. After their characterization, monomers were polymerized electrochemically and properties of vipolymers were also investigated to understand the effectof symmetrical (D-A-D type) and unsymmetrical (D-A-D'type) combination of donor units.Polymerization of CBT and CTBTCmonomers was successfully achieved, and PCTBTCshows multichromic behavior however, its stability was lower than the stability of PCBT.The percent transmittance value of PCBTwas measuredas 12% at 530 nm and the switching time was calculated as 3 s at 95% of the full contrast. For PCTBTC, on the other hand, at 576 nm, percent transmittanceand the switching time was found as 8% and 4.2 s,respectively. It was observed that PCTBTChas the lowest optical band gap value and this value was calculated as 1.44 eV. For PCBT, the optical band gap wascalculated as 1.81 eV.

Subject Keywords

Electrochromic polymers, Donor-acceptor-donor, Benzothiadiazole, Thiophene, Carbazole

URI

https://hdl.handle.net/11511/89606

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Electrochemical synthesis of new conjugated polymers based on carbazole and furan units Oguzturk, H. Esra; TİRKEŞ, SEHA; Önal, Ahmet Muhtar (2015-08-01) In this study, synthesis of four new monomers; 3,6-di(2-furyl)-9H-carbazole (M1), 3,6-di(2-furyl)-9-ethyl-carbazole (M2), 2,7-di(2-furyl)-9-H-carbazole (M3), 2,7-di(2-furyl)-9-(tridecan-7-yl)-9H-carbazole (M4), was achieved via Stifle cross-coupling reaction. The monomers were electrochemically polymerized, via repetitive cycling in acetonitrile-tetrabutylammonium hexafluorophosphate electrolytic medium. Optical and electrochemical properties of the monomers and their corresponding polymers were investigate...
EFFECT OF π-BRIDGES ON ELECTROCHEMICAL AND PHOTOVOLTAIC PROPERTIES OF BENZOTHIADIAZOLE AND BENZODITHIOPHENE BASED CONJUGATED POLYMERS Dikbıyık, Dilan Ece; Çırpan, Ali; Hızalan Özsoy, Gönül; Department of Chemistry (2022-1-28) In this study, a series of the Donor -π bridge- Acceptor type conjugated polymers (PT1, PT2, and PT3) were designed and synthesized via Pd-catalyzed Stille polycondensation reactions. Synthesized polymers were used as donor moieties and blended with acceptor unit PC71BM to form the active layer of the bulk heterojunction organic solar cell (BHJ OSC). Polymers contain electron-deficient benzothiadiazole (BT) as acceptor unit and electron-rich benzodithiophene (BDT) as donor unit. Moreover, thiophene [T], sel...
Carbazole based electrochromic polymers bearing ethylenedioxy and propylenedioxy scaffolds ERGÜN, EMİNE GÜL CANSU; Önal, Ahmet Muhtar (2018-04-15) In this study, synthesis of two new monomers; 2-(2,3-dihydrothieno[3,4-b] (1,4] dioxin-5-yl)-7(2,3-dihydrothieno [3,4-b][1,4]dioxin-7-yl)-9H-carbazole (ECzE) and 2-(3,3-dihexy1-3,4-dihydro2H-thieno[3,4-b][1,4]dioxepin-6yl)-7-(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b] [1,4] dioxepin-8-yl)-9H-carbazole (PCzP), via Stille cross-coupling reaction and their electrochemical polymerization both by repetitive cycling and by constant potential electrolysis was reported. The electrochemical and optical properties of t...
Fused structures in the polymer backbone to investigate the photovoltaic and electrochromic properties of donoracceptor-type conjugated polymers CEVHER, ŞEVKİ CAN; UNLU, Naime Akbasoglu; OZELCAGLAYAN, Ali Can; APAYDIN, Dogukan Hazar; Udum, Yasemin Arslan; Toppare, Levent Kamil; Çırpan, Ali (Wiley, 2013-05-01) In this study, two new benzotriazole (BTz) and dithienothiophene (DTT) containing conjugated polymers were synthesized. After successful characterizations of the monomers by proton-nuclear magnetic resonance (1H NMR) and carbon-NMR (13C NMR) techniques, poly(4-(dithieno[3, 2-b:2,3-d]thiophen-2-yl)-2-(2-octyldodecyl)-2H-benzo[d][1,2,3] triazole) P1 and poly(4-(5-(dithieno[3,2-b:2,3-d]thiophen-2-yl)thiophen-2-yl)-2-(2-octyldodecyl)-7-(thiophen-2-yl)-2H-benzo[d][1,2,3]triazole) P2 were synthesized via a typica...
Comparison of antioxidant enzyme activities and DNA damage in chickpea (Cicer arietinum L.) genotypes exposed to vanadium Imtiaz, Muhammad; Mushtaq, Muhammad Adnan; Rizwan, Muhammad Shahid; Arif, Muhammad Saleem; Yousaf, Balal; Ashraf, Muhammad; Xiong Shuanglian, Xiong Shuanglian; Rizwan, Muhammad; Mehmood, Sajid; Tu, Shuxin (2016-10-01) The present study was done to elucidate the effects of vanadium (V) on photosynthetic pigments, membrane damage, antioxidant enzymes, protein, and deoxyribonucleic acid (DNA) integrity in the following chickpea genotypes: C-44 (tolerant) and Balkasar (sensitive). Changes in these parameters were strikingly dependent on levels of V, at 60 and 120 mg V L-1 induced DNA damage in Balkasar only, while photosynthetic pigments and protein were decreased from 15 to 120 mg V L-1 and membrane was also damaged. It was...

Citation Formats

D. Eroğlu, “Comparison of donor-acceptor-donor type conjugated systems with cross-exchange of donor units,” M.S. - Master of Science, Middle East Technical University, 2020.