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Article Citation - WoS: 11Citation - Scopus: 11Electrochemical and Optical Properties of Substituted Phthalimide Based Monomers and Electrochemical Polymerization of 3,4-Ethylenedioxythiophene Oligomeric Silsesquioxane (poss) Analogue(Elsevier Sci Ltd, 2019) Cakal, Deniz; Ertan, Salih; Cihaner, Atilla; Onal, Ahmet M.A new series of donor-acceptor-donor type trimeric monomers bearing substituted phthalimide units as acceptor units and thiophene and 3,4-ethylenedioxythiophene (EDOT) as donor units was synthesized and characterized. The strength of acceptor units and intramolecular charge transfer between donor and acceptor units were investigated by using electrochemical and optical methods. The main advantage of phthalimide unit over other acceptor units is the ease of its functionalizability. Thus, utilizing this property, a phthalimide derivative (E2P-POSS) bearing polyhedral oligomeric silsesquioxane (POSS) cage was introduced successfully with EDOT and polymerized electrochemically. The corresponding electroactive polymer, PE2P-POSS, has a band gap of 1.72 eV and is an electrochromic polymer: gray when neutralized and eggplant purple when oxidized.Article Citation - WoS: 24Citation - Scopus: 23Synthesis and Electrochemical Polymerization of D-A Type Monomers With Thieno [3,4-c] Pyrrole-4,6 Acceptor Unit(Elsevier Sci Ltd, 2018) Cakal, Deniz; Ertan, Salih; Cihaner, Atilla; Onal, Ahmet M.In this study, three new donor-acceptor-donor type monomers bearing 1,3-dibromo-5-(2-ethylhexyl)-4H-thieno [3,4-c]pyrrole- 4,6(5H)-dione (A) as an acceptor unit and thiophene, 3,4-ethylenedioxythiophene (EDOT) and 3,3-didecy1-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine (didecyl-ProDOT) as donor units were synthesized via Stille cross-coupling reaction and their electrochemical polymerization by repetitive cycling was reported. The electrochemical and optical properties of the monomers ((5-(2-ethyl-liexyl)-1,3-di(thienyl-2-yl)-4H-thienolr-3,4-cl pyrrole-4,6(5H)-dione (TAT), 1,3-bis(2,3-dihydrothieno[3,4-1)] (1,4]dioicin-5-yl)-5-(2-ethylhexyl)-4H-thieno(3,4-c) pyrrole-4,6-(5H)-dione (EAE) and 1,3-bis(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-1)111,41-dioxepin-6-yl)-5-(2-ethylhexyl)-4H-thieno[3,4-apyrrole-4,6(5H)-dione (PAP)) and their corresponding polymers called PTAT, PEAE and PPAP were investigated and it was found that EDOT units containing monomer and polymer (EAE and PEAE) have lower oxidation potentials and lower band gap value as compared to didecyl-ProDOT and thiophene units containing monomers and polymers (PAP, TAT and PPAP, PTAT). Spectroelectrochemical investigations conducted on electrochemically obtained polymer films revealed that polymer films exhibited electrochromic behaviors: brick red to gray for PTAT, blue/violet to highly sky blue for PEAE and blue to highly light blue for PPAP in their neutral and oxidized states, respectively. Moreover, PAP was also polymerized chemically using FeC13 as an oxidizing agent. Both chemically and electrochemically obtained PPAP were found to be soluble in some organic solvents and their dichloromethane solutions can be reversibly oxidized and reduced using antimony pentachloride and hydrazine hydrate solutions, respectively.Article Citation - WoS: 13Citation - Scopus: 13Effect of the Donor Units on the Properties of Fluorinated Acceptor Based Systems(Elsevier Sci Ltd, 2021) Cakal, Deniz; Akdag, Akin; Cihaner, Atilla; Onal, Ahmet M.A new series of monomers in the donor-acceptor-donor array, namely 5-fluoro-4,7-di(furan-2-yl)benzo[c][1,2,5] thiadiazole (F2BT-F), and 5-fluoro-4,7-di(selenophen-2-yl)benzo[c][1,2,5] thiadiazole (S2BT-F), bearing 5-fluorobenzo[c][1,2,5]-thiadiazole as the acceptor moiety and furan and selenophene as the electron donating groups was synthesized and polymerized electrochemically. To compare heteroatom effect, thiophene analogue of newly synthesized (FBT)-B-2-F and S2BT-F namely, (5-fluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5] thiadiazole (T2BT-F)) and its corresponding polymer were also synthesized. Effect of donor units on the electrochemical and optical properties of fluorinated acceptor based systems was investigated in terms of the effect of different sized heteroatoms in five-membered rings on the dihedral angle and planarity. Theoretical calculations also suggested a deviation from planarity upon fluorination. Moreover, electrochemically obtained polymers possess low bandgap values (1.62 eV-1.68 eV for PF2BT-F and PS2BT-F, respectively) and exhibited electrochromic properties with relatively low switching times.
