Condensed polyaromatic

Effect of Carbon on Catalyst. Observing that the average H/C mole ratio for coke on catalyst is >1 and that condensed polyaromatics with similar H/C (e.g., phenanthrene, anthracene) exhibit densities in the range 1 to 1.3, a skeletal density of 1.2 g/cc is assumed for coke on catalyst (14, 15). Then for each 1% addition in coke, for a nominal catalyst density of 2.4,... 

Coke accumulated in the process of partial coking of medium-pore zeolites by olefins is of a condensed, polyaromatic structure and is localized on the surface of the zeolite crystals. 

Nanombes These are comprised of carbon atoms arranged in a condensed polyaromatic surface in a cylindrical stmcture with their ends closed. Due to their unique chemical and electronic properties, they have been manipulated in biomedical sciences as sensors for detecting DNA and protein, diagnostic devices for biochemical estimations (Bianco et al., 2005a). 

Formation kinetics will depend upon the concentrations present in the vapor phase, properties of the encapsulated elements or compounds (such as carbon solubility and carbide formation), buffer gas conditions that controls cooling rates and the possibility of independent carbon condensation (polyaromatic carbon), and other process variables such as temperature and pressure. Catalytic effects can be present not only in the segregation of carbon in solution but also in the kinetic pathways of independent carbon species formed. Magnetic and electric fields can interact in these processes through the presence of paramagnetic (free radicals) and polar species. 

These highly condensed polyaromatic supports do indeed prove to have much better thermo-oxidative stability than vinyl polymer supports (see... 

The studies have been extended to esters that contain condensed polyaromatics in the phenolic substructure. For instance, 1-naphthyl acetate gives 2- and 4-acetyl-1-naphthols [22, 30, 42], whereas in the case of 2-naphthyl acetate, 1-, 3-, 6-, and (marginally) 8-acetyl-2-naphthols are obtained [27, 49-53]. The reaction also works with heterocyclic compounds, such as furan [54], pyridine [55-57], indole [58-60], or chromane [61] derivatives. 

Fig. 3.28. Van Krevelen diagrams of deep-sea DOM. (a) Presentation of all molecules in 3500 m and 4600 m water depth, (b) Enlarged region of condensed polyaromatics where the members of the homologous series (CH2)n with ra > 4 are shown as white circles and connected along a gray line. Reproduced from Ref. [61] with permission. Elsevier Science Publishers, 2006.

Stein, S., Brown, R. (1987). Pi-electron properties of large condensed polyaromatic hydrocarbons. Journal of the American Chemical Society, 109, 3721-3729. 

Other Condensed Polyaromatic Ring(s) Containing Crownophanes. 55... 

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