Dibenzo fluorene

Di-a-naphthoyl 7 1 450. II775. Di- -naphthoyl 7 II 776. 1.2 7.8-Dibenzo-fluoren-carbons4ure.(9)... 

CjgHjoOj 9-Oxy-9-[2-methoxy-phenyI]-1.2 7.8-dibenzo-fluoren 6 II1050. 1.2-Dioxy-1.2 diphenyl-3.4-benzo-acenaphthen 6 I 5. ... 

As might be anticipated from the behaviour of the parent heterocycles, C-2 of indole, benzo[i]furan and benzo[i]thiophene (Table 13) is shifted to lower field than C-3. However, the shifts for C-2 (O, 144.8 Se, 128.8 S, 126.1 NH, 124.7 Te, 120.8) and C-7a (O, 155.0 Se, 141.3 S, 139.6 NH, 135.7 Te, 133.0) in the benzo[i] heterocycles vary irregularly (80OMR(l3)3l9), and the sequence is different to that observed for C-2 in the parent heterocycles, namely 0>Se>Te>S>NH. Also noteworthy is the upheld position of C-7, especially in indole and benzofuran, relative to the other benzenoid carbons at positions 4, 5 and 6. A similar situation pertains in the dibenzo heterocycles (Table 14), where not only are C-1 and C-8 shifted upheld in carbazole and dibenzofuran relative to the corresponding carbons in dibenzothiophene and fluorene, but similar, though smaller, shifts can be discerned for C-3 and C-6 in the former compounds. These carbon atoms are of course ortho and para to the heteroatom and the shifts reflect its mesomeric properties. Little variation in the carbon-hydrogen coupling constants is observed for these dibenzo compounds with V(qh) = 158-165 and V(c,h) = 6-8 Hz. 

The first observation of ionic dissociation of a carbon-carbon cr bond in a hydrocarbon was reported for 7-(2,4,6-cycloheptatrien-l-yl)-7-[3-(7//-dibenzo[c,g]fluoren-7-ylidene)-2-(7//-dibenzo[c,g]fluoren-7-ylidenemethyl)-l-propenyl]-7//-dibenzo[c,g]fluorene [3-2], The hydrocarbon [3-2] forms a green solution in DMSO, indicating the dissociation into green Kuhn s carbanion [2 j and colourless tropylium ion [3" ] as shown in (1) (Okamoto etal., 1985). 

Monna L, T Omori, T Kodama (1993) Microbial degradation of dibenzofuran, fluorene, and dibenzo-p-dioxin by Staphylococcus auriculans DBF63. Appl Environ Microbiol 59 285-289. 

Carbazole, A-methylcarbazole, IV-ethylcarbazole, dibenzofuran, dibenzothiophene, fluorene, dibenzo-p-dioxin, phenoxathiin, phenoxazine, phenothiazine, xanthene, biphenyl, naphthalene, phenanthrene, anthracene, and fluoranthene could be transformed by E. coli, [314] which was transformed using a plasmid bearing the carAa, Ac, and Ad genes, and expressing only the carA-encoded proteins. Further work is needed to develop a final biocatalyst and to prove the advantages that this degradative pathway would incorporate in a refining bioprocess. 

Fig. 10 Composition and spatial distribution of the main patterns of contamination identified in sediment of the Ebro River basin from year 2004 to 2006. Different temporal distribution of the PAHs pattern of contamination over the territory and constant distribution in time of the APs and heavier PAHs as well as the OCs pattern. Big circles representing higher levels of pattern contribution than small circles. Variables identification 1, naphthalene 2, acenaphtylene 3, acenapthene 4, fluorene 5, phenanthrene 6, anthracene 7, fluoranthene 8, pyrene 9, benzo(a) anthracene 10, chrysene 11, benzo(b)fluoranthene 12, benzo(k)fluoranthene 13, benzo(a)pyr-ene 14, indeno(l,2,3-cd)pyrene 15, dibenzo(a,h)anthracene 16, benzo(g,h,i)perylene 17, octyl-phenol 18, nonylphenol 19, tributylphosphate 20, a-HCH 21, HCB 22,2,4-DDE 23,4,4-DDE 24, 2,4-DDD 25, 4,4-DDD 26, 2,4-DDT 27, 4,4-DDT...

Hunter et al. (1974) have reported a striking catalytic effect of dibenzo-18-crown-6 [11] on the decarboxylation of sodium 3-(fluoren-9-ylidene)-2-phenylacrylate [202] in THF solution. At —45°C the salt failed to form a... 

The hypothesis that 128 is twisted in solution and that the transition state to E-Z isomerization has perpendicular fluorene groups was supported by a study of 2,3,2, 3 -dibenzo-annelated 128 (159). In this, the steric situation around the double bond is similar to that in 128a, but an improved stabilization of the diradical perpendicular transition state should lead to a lower barrier to E-Z isomerization, as is found (AG 53 = 23.5 kcal/mol). A close approach of the 1 and 1 (8 and 8 ) positions in 128 is indicated by a through-space H- F coupling of 7 Hz in ( )-l, 1 -difluoro-128 (160). In this compound the barrier to E-Z exchange is >25.6 kcal, because of the small contribution of the fluorine atoms to the ground state strain. 

Diazo fast orange GR, see 2-Nitroaniline Diazo fast orange R, see 3-Nitroaniline Diazo fast red GG, see 4-Nitroaniline 1,2 5,6-Dibenzanthracene, see Dibenz[a,/ ]anthracene l,2 5,6-Dibenz[a,/ ]anthracene, see Dibenz[a,/ ]anthracene l,2 5,6-Dibenzoanthracene, see Dibenz[a,/ ]anthracene Dibenzo[a,/ ]anthracene, see Dibenz[a,/ ]anthracene Dibenzo[6j A ]fluorene, see Benzo[k] fluoranthene Dibenzo[6,d furan, see Dibenzofuran... 

The currently accepted name for (1) in Chemical Abstracts is dibenzothiophene, although biphenylene, diphenylene, or biphenylylene sulfide are still used, especially in the Russian literature. Occasionally 9-thia-fluorene is used and recently, in one instance, dibenzo[6,d]thiophene. An alternative numbering system for (1) is met with on occasions in which C-4 is taken as C-1, as in carbazole. In the absenee of moleeular diagrams this system must be detected by reference to the chemistry described. For example, in a few dyestuff patents 2,7-diaminodibenzothiophene 5,5-dioxide is referred to and this is obviously the 3,7-diamino compound, also known as benzidine sulfone. 

Very recently, a series of novel carbocations and carboxonium ions were generated from 77/-benzo[c]fluorene (80), 1 l//-benzo[Z)]fiuorene (81), ll//-benzo[a]fluorene (82), 2-methoxy- (83), 7-methoxy- (84), and 9-methoxy-l l//-benzo[u]fluorene (85), 7//-dibenzo-[c,g]fluorene (86), 137/-dibenzo[u,g]fluorene (87), 2-methoxy-13//-dibenzo [u,g]fluorene (88), and 5,6-dihydro-13//-dibenzo[u,g]fluorene (89) (Fig. 30). Charge delocalization modes in the resulting carbocations were derived based on experimental and/or computed (GIAO-DFT) A8 C NMR values and via the NPA-deiived changes in charges (A ). 

FIGURE 19.24 HPLC separation of a standard mixture of 16 EU-priority PAHs plus EPA-priority PAHs, benzo[e]pyrene and benzo[fc]chrysene. Na=naphthalene, Ac = acenaphthylene, E=fluorene, Pa=phenan-threne, A = anthracene, El = fluoranthene, P = pyrene, BcE = benzo[c]fluoranthene, CPP = cyclopenta[c,4] pyrene, BaA = benz[a]anthracene, Ch = chrysene, 5-MeCh = 5 methylchrysene, BeP = benzo[e]pyrene, BjE = benzo[/ ]fluoranthene, BbF = benzo[h]fluoranthene, BkE = benzo[l ]fluoranthene, BaP = benzo[a]pyrene, DBahA = dibenz[a,/j]anthracene, DBalP = dibenzo[a,l]pyrene, BghiP = benzo[g,/j,i]perylene, IP = indeno [l,2,3-c4]pyrene, DBaeP = dibenzo[a,e]pyrene, BbCh = benzo[h]chrisene, DBaiP = dibenzo[a,i]pyrene,... 

Aromatic amines Benzo anthracenes Benzo fluoranthracenes Benzo pyrenes Benzoic acids Carbazoles Chrysenes Dibenzo thiophenes Fluorenes Imidazoles Indoles Naphthalenes... 

For the kinetics and mechanisms of the gas-phase reactions of other 2- to 4-ring PAHs with OH radicals, N03 radicals, and 03, see, e.g., phenanthrene, Kwok et al. (1994a), and indan, indene, fluorene, and 9,10-dihy-droanthracene, Kwok et al. (1997) for dibenzo-thiophene, a volatile S-PAC that is ubiquitous in polluted ambient air environments and forms mutagenic photooxidation products, see Kwok et al. (1999) see also Kwok et al. (1994b) for a review of gas-phase NO-, radical reactions with aromatics. 

In the dibenzo heterocycles (Table 11), C-l and C-8 are shifted upfield in carbazole and dibenzofuran relative to the corresponding carbons in dibenzothiophene and fluorene, and similar, though smaller, shifts can be discerned for C-3 and C-6 in the former compounds. 

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