Cross-exchange of donor units in donor-acceptor-donor type conjugated molecules: Effect of symmetrical and unsymmetrical linkage on the electrochemical and optical properties

Eroglu, Deniz
Önal, Ahmet Muhtar
A series of donor-acceptor-donor type molecules were synthesized using carbazole (C) and thiophene (T) as donor units. The donors were connected symmetrically and unsymmetrically to the acceptor unit of benzothiadiazole (B). With having four combinations, CBC, CBT, TBT and CTBTC, changes in the electrochemical and optical behaviors of the monomers were investigated using cyclic voltammetry, differential pulse voltammetry, UV-Vis and Fluorescence spectrometry techniques. Replacing one of the symmetrical C units in CBC with T unit caused a slight red shift in lower energy absorption band. On the other hand, having both C and T units symmetrically in the monomer structure exhibited about 70 nm red shift in the optical absorption. Electrochemical polymerization of the monomers was studied via potential cycling. In the case of formation of polymer films, the effect of exchange and combination of the donors on the electrochemical and optical properties was investigated.


Synthesis of chiral acetoxy lactones via the Baeyer-Villiger oxidation of cyclic aromatic acetoxy ketones
Demir, Ayhan Sıtkı; Aybey, Asuman (Elsevier BV, 2008-12-01)
The alpha-acetoxylation of indanones and tetralones by using Mn(OAc)(3) followed by the enzyme catalyzed kinetic resolution of acetoxy ketones furnished both of the enantiomers of alpha-acetoxy ketones in good chemical and optical yields. The Baeyer-Villiger oxidation of alpha-acetoxy ketones with m-CPBA, CF(3)SO(3)H, and CH(2)O(2), at rt gives the corresponding lactones without racemization. The acetoxy ketone moiety migrates selectively in order to form lactones. The mild hydrolysis of lactones affords ph...
Asymmetric aldol addition of alpha-azido ketones to ethyl pyruvate mediated by a cinchona-based bifunctional urea catalyst
Okumus, Seda; Tanyeli, Cihangir; Demir, Ayhan Sıtkı (Elsevier BV, 2014-07-30)
The first asymmetric synthesis of ethyl 4-aryl-3-azido-2-hydroxy-2-methyl-4-oxobutanoates via a cinchona organocatalyst induced aldol addition of alpha-azido ketones to ethyl pyruvate has been developed. The coupling reaction under optimized conditions was carried out to furnish tetrafunctionalized synthons with enantioselectivities of up to 91:9 and enriched diastereoselectivities of up to 95:5 (syn:anti).
Selective one-pot synthesis of substituted pyrrole-3-phosphonates from alpha-cyanomethyl-beta-ketoesters
Demir, Ayhan Sıtkı; Tural, Servet (Elsevier BV, 2007-05-07)
A one-step synthesis of 5-alkoxypyrrole-3-phosphonates is presented starting from suitable alpha-cyanomethyl-beta-ketophosphonates. The key step in the synthesis involves a one-pot addition and heteroannulation sequence. The zinc perchlorate-catalyzed addition of alcohols to the nitrile carbon of alpha-cyanomethyl- beta-ketophosphonates followed by annulation furnished 5-alkoxypyrrole-3-phosphonates. The addition-annulation process is carried out in the presence of water and 4,5-dihydro-5-oxo-1H-pyrrole-3-p...
Intermolecular heterocyclization of alkynones with 2-mercaptoacetaldehyde under metal-free conditions: synthesis of 2,3-disubstituted thiophenes
Vatansever, Erol Can; Kilic, Kubra; Ozer, Merve Sinem; KOZA, GANİ; Menges, Nurettin; Balcı, Metin (Elsevier BV, 2015-09-30)
A concise and regioselective approach for the synthesis of 2,3-disubstituted thiophene derivatives has been developed. The synthetic strategy relies on the reaction of an in situ generated 2-mercaptoacetaldehyde with various alkynones. Furthermore, we calculated the energy gap between the HOMO and the LUMO orbitals of all compounds and observed that the introduction of a strong electron-withdrawing group decreased the HOMO-LUMO energy gap.
Divergent synthesis of polysubstituted isoxazoles, isoxazoline N-oxides, and dihydroisoxazoles by a one-pot cascade reaction
Rouf, Abdul; ŞAHİN, Ertan; Tanyeli, Cihangir (Elsevier BV, 2017-01-26)
An efficient one-pot synthesis of a new class of 3,4,5-trisubstituted isoxazoline N-oxides/isoxazoles and dihydroisoxazoles is developed by a green approach from aromatic and aliphatic aldehydes by controlling the reaction conditions. Aldehydes were reacted with ethyl nitroacetate in the presence of DABCO as a catalyst under ultrasonication. In aromatic aldehydes, isoxazoline N-oxides were obtained exclusively when the reaction was carried out at 40 degrees C, but raising the temperature to 80 degrees C iso...
Citation Formats
D. Eroglu, E. G. C. ERGÜN, and A. M. Önal, “Cross-exchange of donor units in donor-acceptor-donor type conjugated molecules: Effect of symmetrical and unsymmetrical linkage on the electrochemical and optical properties,” TETRAHEDRON, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: