Coronenes

Problems with heavy feeds, fotmation of polynuclear aromatics (coronene, ovalene, etc.)... 

Corn syrups [8029-43-4] Corn wet-milling Corn whiskey Coronadite [12414-82-3] Corona resistance Coronary bypass Coronary heart disease Coronates Coronavims Coronene [191-07-1] Coromte... 

Fig. 1. Some molecules with different C-C bonds. Al, ethane, CjH, (sp ) A2, ethene, C2H4 (sp ) A3, ethyne, (sp ) Bl, benzene, (aromatic) B2, coronene,...

Fig. 10. H NMR spectra (a) coronene (b) Co-SiOj covered by carbon nanotubulcs (c) Co-SiOj covered by carbon nanotubules and evacuated to 10 torr for the NMR measurement (d) Co-SiO evacuated to 10 torr for the NMR measurement.

Copper(ll) chloride, aromatic iodination and, 551 Coproslanol, structure of, 304 Coral, organohalides from, 352 Corn oil, composition of. 1062 Cornforlh. John Warcup. 1085 Coronene, structure of, 532 Cortisone, structure of. 107 Couper, Archibald Scott, 7 Coupled reactions. 1128-1129 ATP and, 1128-1129 Coupling (NMU), 460... 

Figure 3. Total-luminescence contour plots of an anthracene-coronene mixture prior to extraction (a) and following extraction (b) with y-cyclodextrin.

To investigate the basis set effect in connection with geometric strain in BF, we have performed calculations with and without d-type functions on corannulene. The d-functions improve the binding with about 10 kcal/mol per C-atom in C20H10 the corresponding improvement in coronene (C24H 2) 8 kcal/mol. 

Juhasz AL, ML Britz, GA Stanley (1997) Degradation of benzo[a]pyrene, dibenz[(3,/j]anthracene and coronene by Burkholderia cepacia. Water Sci Technol 36 45-51. 

The biodegradation of pyrene, chrysene, fluoranthene, benz[a]anthracene, dibenz[a,/t] anthracene, benzo[a]pyrene, and coronene by Stenotrophomonas maltophilia has been studied in the presence of a range of synthetic surfactants (Boonchan et al. 1998). Nonneutral surfactants were toxic, biodegradation was also inhibited by the neutral Igepal CA-630, and the positive enhancement of removal of substrates was generally low—in the range of 10%. 

Tables 6.27 and 6.31 show the main characteristics of ToF-MS. ToF-MS shows an optimum combination of resolution and sensitivity. ToF-MS instruments provide up to 40000 spectra s-1, a mass range exceeding 100000 (in principle unlimited), a resolution of 5000, and peak widths as short as 200 ms. This is better than quadruples and most ion traps can handle. Unlike the quadrupole-type instrument, the detector is detecting every introduced ion (high duty factor). This leads to a 20- to 100-times increase in sensitivity, compared to QMS used in scan mode. The mass range increases quadratically with the time range that is recorded. Only the ion source and detector impose the limits on the mass range. Mass accuracy in ToF-MS is sufficient to gain access to the elemental composition of a molecule. A single point is sufficient for the mass calibration of the instrument. ToF mass spectra are commonly calibrated using two known species, aluminium (27 Da) and coronene (300 Da). ToF is well established in combination with quite different ion sources like in SIMS, MALDI and ESI.

The only reported X-ray structure of a it-bonded diiodine exists in the 12/coronene associate [75], which shows the I2 to be located symmetrically between the aromatic planes and to form infinite donor/acceptor chains. -Coordination of diiodine over the outer ring in this associate is similar to that observed in the bromine/arene complexes (vide supra), and the I - C separation of 3.20 A is also significantly contracted relative to the stun of their van der Waals radii [75]. For the highly reactive dichlorine, only X-ray structures of its associates are observed with the n-type coordination to oxygen of 1,4-dioxane [76], and to the chlorinated fullerene [77]. 

Figure 1.7 (a) Molecular model of coronene (b) hexagonal close packing at the van der Waals diameter parts (c) and (d) illustrate the packing advantage, which can be obtained by a concerted rotation, counterclockwise or clockwise, of all molecules to allow... 

Figure 1.8 Diastereoisomeric effects predicted to arise for coronene adsorption on Cu l 1 1 from a combination of molecular rotation (curved arrows) within the 2D adsorbate lattice to allow C—H bond interdigitation and the ( 19 X 19)R 23.4° lattice. The black arrows indicate a high symmetry within the molecule bisecting C—H bonds.

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