Synthesis, spectroscopy, and electrochemical investigation of new conjugated polymers containing thiophene and 1,3,4‐thiadiazole in the main chain

Abstract

Novel photoluminescent donor–acceptor poly(p‐phenylenevinylene)‐type conjugated polymers containing thiophene and 1,3,4‐thiadiazole units in the main chain were synthesized from 2,5‐bis(5‐bromomethyl‐2‐thienyl)‐1,3,4‐thiadiazole and 1,3/1,4‐benzenedialdehyde by Wittig–Horner reaction. The synthesized polymers were characterized by the use of thermal analysis and spectroscopic (infrared, UV‐visible absorption, and photoluminescence) measurement. The resultant material exhibited bluish green, green, and orange fluorescence in their solution and thin film and solid forms, respectively. The redox property of the polymers has also been studied by cyclic voltammetry. The optical and electrochemical studies reveal that these novel polymers are new promising materials for the development of efficient polymer light‐emitting diodes. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Synthesis of New Thiadiazole-Containing Polythiophene Derivatives and Their Application to Organic Solar Cells

“…For instance, a structure similar to the benzothiadiazole units have frequently been utilized as an A unit in D-A polymers to achieve high PCEs [17][18][19][20][21][22]. However, a few reports have described the PSCs using D-A type polymers bearing TD units [23,24], regardless of its electron-withdrawing nature as well as the more compact structure without hydrogen atom at 3-and 4-positions, compared to the benzothiadiazole units, which would be preferable for more densely packed structures for the polymer films to induce a high charge mobility.…”

Optoelectronic and conductivity of ᴫ‐conjugated polymers based on phenylenevinylene, 1,3,4‐thiadiazole and thiophene: Suitable candidates for n‐type organic semiconductors

“…The E vert of the monomer increased when moving from the electron‐withdrawing substituent to the electron‐releasing substituents, reflecting the weak electron‐withdrawing nature of CHO–PhTAT–CHO compared with CHO–PhTAT–CH 2 –P(=O)(OCH 3 ) 2 . The reported experimental H–PhTAT–H polymer value in chloroform solution is 2.75 eV, which corresponds to 8 monomeric units (the molecular mass is 2800 g/mol). The reliability of TD calculations results obtained from Figure A,B was compared with the experimental data of optical bandgap of the polymers.…”

“…As a result, the effect of the terminal groups was small to lower E LUMO at limit polymer. In chloroform solution, only 3.43 eV experimental LUMO has been calculated from the cyclic voltammetry which agrees with the reported value for unsubstituted polymer . Compared with the experimental LUMO energy, the differences in the LUMO energy calculated for B3LYP/6‐31G (d) and B3LYP/6‐311G (d) take 0.65 and 0.45 eV in all systems, respectively.…”

“…The efficiency of an n‐type organic semi‐conductor relies on the ease of electron injection into the material and the mobility of electrons inside the material . On the basis of the synthesis of p ‐phenylenevinylene–thiophene–1,3,4‐thiadiazole–thiophene (H–PhTAT–H) via Wittig‐Horner polymerization reaction, the terminal groups can be chosen. The terminal group –CH 2 –P(=O)(OCH 3 ) 2 in H–PhTAT–H is considered as electron‐releasing group and –CHO as electron‐withdrawing group (Figure ).…”

Synthesis of Thiophene-Based π-Conjugated Polymers Containing Oxadiazole or Thiadiazole Moieties and Their Application to Organic Photovoltaics

“…1,3,4-Oxadiazole (OXD) and 1,3,4-thiadiazole (TD) are electron-deficient units containing two electron-withdrawing imine groups (CN) and can be used as A units. For instance, a structure similar to the benzothiadiazole units has frequently been utilized as an A unit in D–A polymers to achieve high PCEs. − However, a few reports have described the PSCs using D–A type polymers bearing OXD and TD units, , regardless of their electron-withdrawing nature, as well as more compact structures compared to the benzothiadiazole units, which would be preferable for more densely packed structures for the polymer films to induce a high charge mobility.…”