Synthesis, Characterization, and Optical and Electrochemical Properties of New 2,1,3-Benzoselenadiazole-Based CT-Type Copolymers

New alternating donor−acceptor charge-transfer (CT)-type copolymers consisting of didodecyloxy-p-phenylene (Ph), N-(4-dodecyloxyphenyl)carbazole (Cz), or N-hexyldiphenylamine (Da) unit (π-electron donor) and 2,1,3-benzoselenadiazole (BSe) unit (π-electron acceptor) were prepared by palladium-catalyzed Suzuki coupling reaction in 85−96% yields. The copolymers with the Ph and Cz units were soluble in common organic solvents and gave number-average molecular weights of 8300 and 6600, respectively, in GPC analysis; the copolymer with the Da unit was partly soluble in the solvents. The UV−vis absorption peak of the polymers appeared in the range of 420−530 nm in solutions and films, and the optical transition is considered to be accompanied by CT from the donor unit to the BSe unit. Quantum-chemical calculations of a trimeric model compound (Ph−BSe−Ph:  10) supported the notion that the optical activation of the copolymer involved the CT process. Cyclic voltammetry revealed that the copolymers were susceptible to both electrochemical oxidation and reduction, and they had a LUMO level ranging from −3.08 to −2.91 eV and a HOMO level ranging from −5.56 to −5.12 eV. Comparison of the electronic effect of the BSe unit with that of a 2,1,3-benzothiadiazole unit is discussed

New Alternative Donor−Acceptor Arranged Poly(Aryleneethynylene)s and Their Related Compounds Composed of Five-Membered Electron-Accepting 1,3,4-Thiadiazole, 1,2,4-Triazole, or 3,4-Dinitrothiophene Units: Synthesis, Packing Structure, and Optical Properties

A series of new poly(aryleneethynylene)-type π-conjugated copolymers, which consist of an electron-accepting 1,3,4-thiadiazole, 4-alkyl-1,2,4-triazole, or 3,4-dinitrothiophene unit and an electron-donating 1,4-didodecyloxybenzene or N-dodecylpyrrole unit, were prepared in 81−93% yields by palladium-catalyzed polycondensation. Their related model compounds (PhC≡C−Ar−C≡CPh; Ar = the electron-accepting unit) were also synthesized. GPC traces of the polymers gave number average molecular weights (Mn's) of 6900−29 700. The polymers formed a molecular assembly and a birefringent phase as revealed by powder X-ray diffraction (XRD) analysis and polarized light optical microscopy (POM). They formed an aligned structure on a platinum plate. The UV−vis peaks of the polymers appeared in the range of 385−522 nm in solutions, and the peak was shifted by 10−44 nm to a longer wavelength in films, according to intermolecular electronic interaction. The density functional theory (DFT) calculations supported the presence of strong intermolecular interaction between the polymer molecules. The polymers composed of a 1,3,4-thiadiazole or a 1,2,4-triazole unit exhibited photoluminescence with quantum yields of about 50% in chloroform. The polymers were electrochemically active and showed the reduction peak in a range of −1.1 through −2.2 V vs Ag+/Ag

New Alternative Donor−Acceptor Arranged Poly(Aryleneethynylene)s and Their Related Compounds Composed of Five-Membered Electron-Accepting 1,3,4-Thiadiazole, 1,2,4-Triazole, or 3,4-Dinitrothiophene Units: Synthesis, Packing Structure, and Optical Properties

A series of new poly(aryleneethynylene)-type π-conjugated copolymers, which consist of an electron-accepting 1,3,4-thiadiazole, 4-alkyl-1,2,4-triazole, or 3,4-dinitrothiophene unit and an electron-donating 1,4-didodecyloxybenzene or N-dodecylpyrrole unit, were prepared in 81−93% yields by palladium-catalyzed polycondensation. Their related model compounds (PhC≡C−Ar−C≡CPh; Ar = the electron-accepting unit) were also synthesized. GPC traces of the polymers gave number average molecular weights (Mn's) of 6900−29 700. The polymers formed a molecular assembly and a birefringent phase as revealed by powder X-ray diffraction (XRD) analysis and polarized light optical microscopy (POM). They formed an aligned structure on a platinum plate. The UV−vis peaks of the polymers appeared in the range of 385−522 nm in solutions, and the peak was shifted by 10−44 nm to a longer wavelength in films, according to intermolecular electronic interaction. The density functional theory (DFT) calculations supported the presence of strong intermolecular interaction between the polymer molecules. The polymers composed of a 1,3,4-thiadiazole or a 1,2,4-triazole unit exhibited photoluminescence with quantum yields of about 50% in chloroform. The polymers were electrochemically active and showed the reduction peak in a range of −1.1 through −2.2 V vs Ag+/Ag

Synthesis, Solid Structure, and Optical Properties of New Thiophene-Based Alternating π-Conjugated Copolymers Containing 4-Alkyl-1,2,4-triazole or 1,3,4-Thiadiazole Unit as the Partner Unit

Synthesis, Solid Structure, and Optical Properties of New Thiophene-Based Alternating π-Conjugated Copolymers Containing 4-Alkyl-1,2,4-triazole or 1,3,4-Thiadiazole Unit as the Partner Uni

New Alternative Donor−Acceptor Arranged Poly(Aryleneethynylene)s and Their Related Compounds Composed of Five-Membered Electron-Accepting 1,3,4-Thiadiazole, 1,2,4-Triazole, or 3,4-Dinitrothiophene Units: Synthesis, Packing Structure, and Optical Properties

A series of new poly(aryleneethynylene)-type π-conjugated copolymers, which consist of an electron-accepting 1,3,4-thiadiazole, 4-alkyl-1,2,4-triazole, or 3,4-dinitrothiophene unit and an electron-donating 1,4-didodecyloxybenzene or N-dodecylpyrrole unit, were prepared in 81−93% yields by palladium-catalyzed polycondensation. Their related model compounds (PhC≡C−Ar−C≡CPh; Ar = the electron-accepting unit) were also synthesized. GPC traces of the polymers gave number average molecular weights (Mn's) of 6900−29 700. The polymers formed a molecular assembly and a birefringent phase as revealed by powder X-ray diffraction (XRD) analysis and polarized light optical microscopy (POM). They formed an aligned structure on a platinum plate. The UV−vis peaks of the polymers appeared in the range of 385−522 nm in solutions, and the peak was shifted by 10−44 nm to a longer wavelength in films, according to intermolecular electronic interaction. The density functional theory (DFT) calculations supported the presence of strong intermolecular interaction between the polymer molecules. The polymers composed of a 1,3,4-thiadiazole or a 1,2,4-triazole unit exhibited photoluminescence with quantum yields of about 50% in chloroform. The polymers were electrochemically active and showed the reduction peak in a range of −1.1 through −2.2 V vs Ag+/Ag

New Alternative Donor−Acceptor Arranged Poly(Aryleneethynylene)s and Their Related Compounds Composed of Five-Membered Electron-Accepting 1,3,4-Thiadiazole, 1,2,4-Triazole, or 3,4-Dinitrothiophene Units: Synthesis, Packing Structure, and Optical Properties

A series of new poly(aryleneethynylene)-type π-conjugated copolymers, which consist of an electron-accepting 1,3,4-thiadiazole, 4-alkyl-1,2,4-triazole, or 3,4-dinitrothiophene unit and an electron-donating 1,4-didodecyloxybenzene or N-dodecylpyrrole unit, were prepared in 81−93% yields by palladium-catalyzed polycondensation. Their related model compounds (PhC≡C−Ar−C≡CPh; Ar = the electron-accepting unit) were also synthesized. GPC traces of the polymers gave number average molecular weights (Mn's) of 6900−29 700. The polymers formed a molecular assembly and a birefringent phase as revealed by powder X-ray diffraction (XRD) analysis and polarized light optical microscopy (POM). They formed an aligned structure on a platinum plate. The UV−vis peaks of the polymers appeared in the range of 385−522 nm in solutions, and the peak was shifted by 10−44 nm to a longer wavelength in films, according to intermolecular electronic interaction. The density functional theory (DFT) calculations supported the presence of strong intermolecular interaction between the polymer molecules. The polymers composed of a 1,3,4-thiadiazole or a 1,2,4-triazole unit exhibited photoluminescence with quantum yields of about 50% in chloroform. The polymers were electrochemically active and showed the reduction peak in a range of −1.1 through −2.2 V vs Ag+/Ag