Classification Based On Electronic Structure
Heterocyclic compounds can be usefully classified based on their electronic structure. The saturated heterocycles behave like the acyclic derivatives. Thus, piperidine and tetrahydrofuran are conventional amines and ethers, with modified steric profiles. Therefore, the study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles are fused to benzene rings, which for pyridine, thiophene, pyrrole, and furan are quinoline, benzothiophene, indole, and benzofuran, respectively. Fusion of two benzene rings gives rise to a third large family of compounds, respectively the acridine, dibenzothiophene, carbazole, and dibenzofuran. The unsaturated rings can be classified according to the participation of the heteroatom in the pi-system.
Read more about this topic: Heterocyclic Compound
Famous quotes containing the words based, electronic and/or structure:
“The time must come, my friend ... when brutality and the lust for power must perish by its own sword.... For when that day comes, the world must begin to look for a new life, and it is our hope that they may find it here. For here we shall be, with their books, and their music, and a way of life based on one simple rule: Be kind.”
—Robert Riskin (1897–1955)
“The new electronic interdependence recreates the world in the image of a global village.”
—Marshall McLuhan (1911–1980)
“... the structure of our public morality crashed to earth. Above its grave a tombstone read, “Be tolerant—even of evil.” Logically the next step would be to say to our commonwealth’s criminals, “I disagree that it’s all right to rob and murder, but naturally I respect your opinion.” Tolerance is only complacence when it makes no distinction between right and wrong.”
—Sarah Patton Boyle, U.S. civil rights activist and author. The Desegregated Heart, part 2, ch. 2 (1962)