Thermal Reactivity of Polynuclear Aromatic Hydrocarbons¹

Abstract

Much recent interest has been directed toward understanding the reactivity characteristics of polynuclear aromatic systems. The major emphasis has pertained to simple radical substitution and oxidation-reduction reactions. Relatively little work has been applied to studies of self-condensation sequences, which are generally accomplished thermally and lead to the formation of complex carbonaceous residues from the typical polynuclear aromatic hydrocarbon. We report herein investigations of the thermal reactivity for eighty-four polynuclear aromatic hydrocarbons. Our approach has employed differential thermal analysis (d.t.a.) to categorize and delineate thermal reactivity. These results emphasize the importance of intermolecular thermal hydrogen transfer for the polynuclear aromatics. Thermal condensation reactivity is found to be dependent on molecular structure and correlates with other reactivity criteria but includes the additional parameter of molecular size.Much recent chemical interest has been directed toward studies in the field of polynuclear aromatic hydrocarbons. Special emphasis has been placed on theoretical treatments of these materials2ab and the relationship of theoretical parameters to spectroscopic,3 reactivity,4-6 and physiological8 criteria. Chemical

Kinetics and Catalysis of Carbon Gasification

“…By applying first-order perturbation theory to the Huckel molecular orbitals (Heilbronner et al 1976), They estimated electron localization energies (δΕ π ). Previous workers (Lewis et al 1963, Madison et al 1963) also supported these findings. They found that molecules with "zig-zag" edges (A) are more reactive than molecules with "arm-chair" edges (B) (Figure 1).…”

Petroleum Asphaltenes - Part 2: the Effect of Asphaltene and Resin Constituents on Recovery and Refining Processes

“…Thermal cracking of model compounds confirm that volatility of the fragments is a major influence in carbon residue formation. Indeed, the formation of a coke-like substance during thermal decomposition of aromatic compounds and related heterocyclic compounds are dependent upon the structure, and hence the volatility, of the polynuclear aromatic hydrocarbon but more specifically on: -the degree of polynuclear condensation in petroleum; -the average number of alkyl groups on the polynuclear aromatic systems; -the occurrence of heteroatoms in the ring; -the type of heteroatom (Madison and Roberts, 1958;Lewis and Edstrom, 1963;Singer, 1964, 1967;Lewis, 1980Lewis, , 1982. Nitrogen species also appear to contribute to the pattern of the thermal cracking.…”

Theoretical and experimental studies on the Raman spectra of electrosynthesized polynaphthalene

“…5. The weight‐loss temperature at about 380 °C can be attributed to the loss of dinaphthalene because this temperature is consistent with the boiling point of dinaphthalene 19, 20. The weight‐loss temperature lower than 100 °C is assigned to the evaporation or decomposition of the low‐molecular‐weight components, including carbonyl compounds.…”