Accession Number : ADA292968

Title :   Effects of Molecular Structure on the Electroactive and Optical Properties of Conjugated Rigid-Rod Polybenzobisazoles.

Descriptive Note : Technical rept.,

Corporate Author : ROCHESTER UNIV NY DEPT OF CHEMICAL ENGINEERING

Personal Author(s) : Osaheni, John A. ; Jenekhe, Samson A.

PDF Url : ADA292968

Report Date : 20 MAR 1995

Pagination or Media Count : 55

Abstract : The effects of molecular structure on the electronic structure and electrochemical and linear optical properties of a series of pi-conjugated rigid-rod polybenzobisazoles, including three new polymers, were explored by cyclic voltammetry and measurement of the optical dispersion of the refractive index. The electrochemical reduction of the polymers was reversible whereas oxidation was not reversible in accord with the electron deficient nature of the benzobisazole ring. The observed variation of the reduction and oxidation potentials, electron affinity, and ionization potential of the series of polymers was related to the variation in backbone structure. The electron affinity of the polymers was 2.4 to 3.0 eV which indicated that the LUMO energy level was tunable by up to 0.6 eV. The ionization potential (5.2 to 5.7 eV) and associated HOMO level of the polymers was tunable by up to 0.5 eV. The measured wavelength dispersion of the refractive index of the polybenzobisazoles showed that n(lambda = 1064 nm) and n(lambda = 2500 run) were 1.74-2.03 and 1.55-1.95 respectively. The large refractive index variation with molecular structure was satisfactorily accounted for by the competing effects of polarizability and molar volume. These results provide a basis for understanding the electronic, optoelectronic, and optical properties of the conjugated polybenzobisazoles in terms of the underlying molecular and electronic structures. jg

Descriptors :   *OPTICAL PROPERTIES, *POLYMERS, *MOLECULAR STRUCTURE, FREQUENCY, ELECTRONICS, POLARIZATION, DISPERSING, STRUCTURAL PROPERTIES, REFRACTIVE INDEX, ELECTRONIC EQUIPMENT, ELECTROCHEMISTRY, CYCLES, REDUCTION, VARIATIONS, ELECTRONS, OXIDATION, ENERGY LEVELS, VOLTAMMETRY, BENZYL RADICALS, MOLECULAR ORBITALS, IONIZATION POTENTIALS, POTENTIAL THEORY, AZOLES.

Subject Categories : Polymer Chemistry
      Organic Chemistry
      Physical Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE