Progress in polyacetylene chemistry

Control of electrical properties of polymers by chemical modification

Publisher Summary This chapter discusses azulenes, its occurrence and synthesis, structure, reactivity, and application. This chapter is restricted to azulenes directly fused to heterorings showing maximum unsaturation or to the corresponding tautomers. Most syntheses under review are based on azulene, cycloheptatriene or cyclopentadiene derivatives and consist in cyclizations to form the heterorings. Deliberate dehydrogenation of natural hydroazulenes and other sesquiterpene derivatives, sometimes after preceding dehydration, hydrogenation, and reduction, has been the first synthetic path to azulenes. The pharmaceutical uses include Linderazulene and its dihydro compound that are found to exhibit antitumor, antifungal, and immunostimulating activities. They are also used in information recording. Polymethine dyes containing the azulenium moiety are suitable as charge generators for electrophotography, especially for semiconductor laser-recording media showing both high sensitivity in recording and stability in reading.

Chapter 3 Azulenes Fused to Heterocycles

Publisher Summary This chapter includes monographs and reviews published during the period 1979-1986, and is not restricted to reviews in English. Sources in Russian, German, Japanese, French, Czech, Polish, and other languages are surveyed and classified. The survey is based mainly on short bibliographic articles published by the author and co-workers in the Soviet journal Khimiya Geterotsiklicheskikh Soedinenii (Chemistry of Heterocyclic Compounds) since 1979. Several important reviews and monographs published before 1979 in languages other than English are also included. Although all the references are given to original publications, other journals also have informative abstracts and their schemes, also lists of the references are quite understandable and very useful.

The Literature of Heterocyclic Chemistry, Part III

The conjugated-circuit model with an improved set of Q n parameters is applied to non-alternant hydrocarbons. The resonance energy per π electron (REPE) model (with a corrected set of parameters) and the hardness model are also applied to the same group of non-alternants. It is found that the RE/e (the resonance energy per π electron calculated using the conjugated-circuit model) and the REPE are intercorrelated quantities, whereas RE/e or REPE do not correlate with absolute hardness at all for non-alternants. Therefore RE/e was selected as the criterion for aromatic stability, and hardness as the reactivity criterion because it is defined in terms of the frontier orbitals. The stability (high aromaticity and low reactivity) of a non-alternant molecule is then judged by both the RE/e and the hardness. In most cases the stability predictions were in agreement with the available experimental evidence. Buckminsterfullerene, which is a spherical non-alternant structure, is found to be a hard molecule, but not as hard as benzene.

The conjugated-circuit model: application to nonalternant hydrocarbons and a comparison with some other theoretical models of aromaticity

Luminescence spectra of certain polymers of the acetylene series

Electronic spectra of polymers with conjugated bonds

Structural transformations and electrophysical properties of polyphenylacetylene in the process of thermolysis

The principal methods of synthesis of polycyclic azulene hydrocarbons and their derivatives are described and certain aspects of the practical applications of polycyclic azulenes are considered. The bibliography includes 122 references.

https://iopscience.iop.org/article/10.1070/RC1982v051n11ABEH002942/pdf

M. I. Cherkashin

Papers

Luminescence spectra of certain polymers of the acetylene series

Electronic spectra of polymers with conjugated bonds

Structural transformations and electrophysical properties of polyphenylacetylene in the process of thermolysis

Polycyclic Azulenoid Systems

Thermal degradation of ladder polymers of diphenylbutadiine