New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties

Abstract

In this paper we present a synthetic approach to six new D–π–A–D conjugated chromophores containing the N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment. Such readily functionalizable heterocycle as carbazole was used as a main starting compound for their preparation. The investigation of the optical properties has shown that the positive solvatochromism is inherent to the chromophores containing an electron-withdrawing prop-2-en-1-one fragment, while the compounds containing a 2-aminopyrimidine moiety exhibit both positive and negative solvatochromism. The fluorescence quantum yields were experimentally determined for some of the synthesized chromophores; e.g., 1-(5-arylthiophen-2-yl)ethanones quantum yields were found to lie in an interval of 60–80%. Electrochemical oxidation of the synthesized chromophores has resulted in the formation of colored thin oligomeric films that became possible due to the presence of carbazole or pyrrole fragments with free electron-rich positions.

Bis-Kalkon Türevlerinin Elektrokimyasal Davranışlarının İncelenmesi

“…Eox onset and Ered onset is the oxidation and reduction onset potentials, respectively. The energy value of 4.8 eV is known to be the value determined below the vacuum level of the onset oxidation potentials (Eox onset ) of ferrocene/ferrocenium (Fc/Fc + ) and is used as a calibration reference (Jin et al, 2014;Cogal et al, 2014;Selinova et al, 2017). HOMO energy levels are calculated to be -5.83 and -5.93 eV, while LUMO energy levels are determined to be -3.08 and -3.0 eV for P1 and P2, respectively.…”

“…The highest occupied molecular orbital (HOMO)--the lowest unoccupied molecular orbital (LUMO) energy gap, also known as the electrochemical band gap (Eg elec ), can be calculated from the difference between initial oxidation and reduction potentials using the cyclic voltammograms (Muto et al, 2001;Jin et al, 2014;Cogal et al, 2014;Asiri et al, 2014). In order to obtain an understanding of the structure-property relationship of the compounds, the calculations of the HOMO energy levels of these compounds were performed front the onset oxidation potential of the cyclic voltammogram, using the following equations (1), (2), (3) (Jin et al, 2014;Cogal et al, 2014;Selinova et al, 2017): (2) Eg elec = (LUMO -HOMO)eV…”

One‐potandtwo‐potmethods for chalcone derived pyrimidines synthesis and applications

“…[231] Carbazolepyrimidine has been synthesized from chalcone reaction with guanidine sulfate under reflux with 25%-42% yield of the desired product (91). [232] Whereas, the N-[ω-(4-methoxyphenoxy)alkyl]carbazole moiety based quadrupolar pyrimidine-chromophores (92) were successfully achieved by cyclization of (90), oxidation, and Clausson-Kaas condensation with the aid of using 2,5dimethoxytetrahydrofuran (DMTHF) as succinic aldehyde with 60%-80% yield [233] (Scheme 22). The compounds (91 and 92) both have electrochemical properties, electrochemical polymerization studies of these derivatives depicted rise to stable colored conjugated-polymeric films under cyclic voltammetry via oxidation.…”

Luminescent Mono‐, Di‐ and Trisubstituted 2,4,6‐Triphenylpyridine‐Based Molecules: Synthesis and Properties

“…[33] Recently, the synthesis and properties of pyrimidine-based D-π-A-π-D blue luminescence emitters were reported by the authors. [34][35][36] In these studies, the number, position and strength of electron-donating substituents were varied. The synthesized blue fluorescence compounds were characterized by high values of glass transition temperature, fluorescence quantum yield and molar absorption coefficient.…”

“…Recently, the synthesis and properties of pyrimidine‐based D‐π‐A‐π‐D blue luminescence emitters were reported by the authors [34–36] . In these studies, the number, position and strength of electron‐donating substituents were varied.…”