Synthesis and processing of heterocyclic polymers as electronic, optoelectronic, and nonlinear optical materials. 2. New series of conjugated rigid-rod polyquinolines and polyanthrazolines

Abstract

A series of 13 new homopolymers and three new copolymers along with six previously known polymers were synthesized and characterized in the class of conjugated polyquinolines and polyanthrazolines. The polymers were designed to systematically vary the ^-electron delocalization along the conjugated polymer backbone and, thereby, to tune the electronic structure and properties in a controlled fashion. The solid polymers, which exhibit a range of light yellow to deep red color in transmitted light, were obtained in high yield, with high intrinsic viscosity and high thermal stability. As a result of the rigid-rod nature of the polymer chains, lyotropic liquid crystalline phases were observed at high concentrations of the polymers in di-m-cresyl phosphate/m-cresol (1:3) solvent. An investigation of the electronic structure of the polymers by optical absorption spectroscopy of the polymer thin films revealed that the structural modifications in the polymers can vary the optical band gap by about 1.0 eV. For example, compared to the biphenyldiyl linked polyquinoline (PBPQ, 2b) which has a band gap (Et) of 2.81 eV, the dithienylvinylene linked polyanthrazoline (PBVDA, 3k) exhibited a drastically lower band gap of 2.0 eV. In general, replacement of a phenylene linkage by a thiophene linkage in the polyquinoline or polyanthrazoline backbone produced a significant red shift of Xm.. by 64-106 nm and a reduction of band gap by 0.3-0.5 eV. The new polymers are expected to have improved electronic, photoelectronic, and nonlinear optical properties for applications and serve as model systems for investigating structure-property relationships in conjugated polymers.

Chemical oxidative polymerization, optical, electrochemical and kinetic studies of 8-amino-2-naphthol

“…Also, the broad peaks at both 1212 and 3160 cm −1 indicate the presence of naphthenic hydroxyl groups in the polymer structure. However, the bands observed at nearly 1600 cm −1 for both AN and OAN are due to the characteristic imine vibrations of the quinoid rings [29,30]. The absorption bands 1445 and 1520 cm −1 correspond to C = C skeletal vibrations of the aromatic ring.…”

Synthesis of rod-coil diblock copolymers by ATRP and their honeycomb morphologies formed by the ‘breath figures’ method

“…Apart from the wide range of different selfassembling structures that form, another unique characteristic of these materials is that the rod segments can endow various functionalities, such as photophysical and electrochemical properties, to the materials. Incorporation of p-conjugated polymer chains into heterogeneous diblock copolymers can create new materials that present promising nonlinear optical, photoconductive, and electroluminescence properties [8][9][10].…”

Perfluoroalkyl-substitution versus electron-deficient building blocks in design of oligothiophene semiconductors

“…Replacing the central thiophene with benzothiadiazole ring in 4T-BTD and DFH-4T-BTD leads to a more significant red-shift in absorbance, characteristic of intramolecular charge transfer. 29,30 Thus the outer thiophene rings of DFH-4T-BTD retain a substantial donor character relative to the benzothiadiazole core, even with the electron withdrawing perfluorohexyl substituents.…”