Reactivity parameters and aromatic systems. Part I. Detritiation rates in fluoranthene

Bancroft, K. C. C.; Howe, G. R.

doi:10.1039/j29700001541

Cited by 6 publications

(13 citation statements)

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“…Thus, ortho substitution had occurred giving isomers having either a 4-and a 2-C 6 H 4 OPh substituent or two 2-C 6 H 4 OPh substituents present, which was confirmed by the 19 F NMR spectrum ( Figure 1). For C 60 F 18 and derivatives, the fluorine resonances fall generally within the following four main areas of d F values: 128-134 (the three outermost fluorine atoms), 136-138 (the six fluorine atoms attached to the central aryl ring), 141-151 (the six fluorine atoms further out from this ring), 157-170 ppm (the three fluorine atoms surrounded by three sp 3 -hybridised carbon atoms.…”

Section: Substitutions Of the Individual Aromatic Compoundssupporting

confidence: 54%

“…The structure was confirmed by the 19 F NMR spectrum which at low temperature became more complicated due to restricted rotation of the 2-fluorene substituents which may lie in either "A" or "B" conformations, giving three possibilities: AAA, ABB, AAB.…”

Section: Substitutions Of the Individual Aromatic Compoundsmentioning

confidence: 62%

“…We anticipated reaction at the 2-position of biphenylene since it is the most reactive towards electrophilic substitution, [17] and this was confirmed by the single-crystal X-ray structure of the orange crystals of the mono-substitution product, two views of which are shown in Figure 3. The structure of C 60 F 17 (1-naphthyl) ( Figure 5) was confirmed by EI mass, 1 H, and 19 F NMR spectra (see Experimental Section). The mass spectrum (see Figure 10) differs from that of the 2-naphthyl isomer, in the presence of the 1150 amu peak due to HF elimination of H 8 Fluoranthene: This gave both mono-(1244 amu) and bis-(1426 amu) substitution products.…”

Section: Substitutions Of the Individual Aromatic Compoundsmentioning

confidence: 79%

“…Thus in the reaction with benzene, the product with a retention time of 6.1 min was shown by both 1 H NMR and 19 F NMR spectra to contain both phenyl and tolyl groups. This was accompanied by a fraction with a retention time of 7.85 min, which was attributed to C 60 F 15 Ph 3 (giving identical mass, 1 H NMR and 19 F NMR spectra to those described previously).…”

Section: Resultsmentioning

confidence: 98%

“…The NMR spectra were in each case very complicated as expected since there are two sites each more reactive than the 1-position of naphthalene, and two each more reactive than the 2-position of naphthalene. [19] Consequently a mixture of derivatives results.…”

Section: Substitutions Of the Individual Aromatic Compoundsmentioning

confidence: 98%

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Electrophilic Aromatic Substitution by the Fluorofullerene C₆₀F₁₈

Darwish

Avent

Abdul‐Sada

et al. 2004

Chemistry A European J

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The FeCl3-catalysed arylation of C60F18 gives tri-substituted compounds C60F15Ar3, where Ar=phenyl, 4-tolyl, 4-methoxyphenyl, 4-phenoxyphenyl, 4-chlorophenyl, 3,4-dichlorophenyl, 2-biphylenyl and 2-fluorenyl, together with some bis- and mono-substituted product. Bis-substitution was achieved with biphenylene and fluoranthene, and mono-substitution with biphenylene (2-position), pyrene (1-position), and naphthalene (1- and 2-positions); the tris-phenyl and tris-biphenylene derivatives are fluorescent. The 2-naphthyl substituent freely rotates at 328 K, whereas rotation of the 1-naphthyl substituent is prevented by interaction of the peri-hydrogen atom with fluorine. The 1-naphthyl derivative eliminates a molecule of HF during EI mass spectrometry, whilst the 2-naphthyl derivative eliminates HF and all fluorenes to give a naphthaleno[60]fullerene. The reaction rate is relatively unaffected by electron supply in the aryl rings, but no product was obtained with benzotrifluoride which defines the lower reactivity limit. The low discrimination between aromatics makes it possible to isolate derivatives having different aryl groups attached to the cage. Reactions occur mainly when the reagent solutions (or solutions in 1,2-dichlorobenzene) are evaporated to dryness. In most FeCl3-catalysed reactions, unreacted C60F18 was recovered, more if the less effective SnCl4 was used as a catalyst; use of AlCl3 resulted in polyarylation and degradation of the C60F18. The structure of C60F17(1-biphenylyl) was confirmed by single-crystal X-ray analysis. Reaction of C60F18 with perylene/FeCl3/o-dichlorobenzene gave red fluorescent "tagliatelli"-like threads (up to 1 cm long) of self-assembled pi-stacked tetrachloroperylene arising from chlorination by FeCl3.

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Section: Substitutions Of the Individual Aromatic Compoundssupporting

confidence: 54%

Section: Substitutions Of the Individual Aromatic Compoundsmentioning

confidence: 62%

Section: Substitutions Of the Individual Aromatic Compoundsmentioning

confidence: 79%

Section: Resultsmentioning

confidence: 98%

Section: Substitutions Of the Individual Aromatic Compoundsmentioning

confidence: 98%

See 3 more Smart Citations

Electrophilic Aromatic Substitution by the Fluorofullerene C₆₀F₁₈

Darwish

Avent

Abdul‐Sada

et al. 2004

Chemistry A European J

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ChemInform Abstract: REAKTIVITAETSPARAMETER UND AROMATISCHE SYST. 1. MITT. DETRITIIERUNGSGESCHWINDIGKEIT BEI FLUORANTHEN

Bancroft¹,

Howe²

1970

Chemischer Informationsdienst. Organische Chemie

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Correlation of molecular orbital indices of reactivity and proton chemical shifts: Acenaphtho[1,2‐b]‐ and ‐[1,2‐c]thiophens

Bartle

1973

Org. Magn. Reson.

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Abstract-Nuclear magnetic resonance proton chemical shifts may be correlated with free valence, a representative reactivity index, for fluoranthene and two novel sulphur heterocyclic analogues, acenaphtho [l,2-b]-and -[I ,2-c]thiophens. Such correlations arise fortuitously, however, and an attempt to explain them in terms of intrinsic properties of the Huckel-McWeeny theory of proton shielding is proved to be fallacious.APPARENT correlations between nuclear magnetic resonance proton chemical shifts (&), and both Hiickel MO and SCF reactivity indices, to and experimental reactivities5 in alternant polynuclear benzenoid hydrocarbons, have led to a number of applications of this approach to non-alternant hydrocarbons,6 hydrocarbon ions6 and heterocyclic molecules.'~* Thus, Clin and Salier have pointed out a relation between carcinogenicity and the sign of the deviation for K (or Krebs) region protons from a graph of 6, against superdelocalisability.* This idea is attractive from the standpoint of predicting both the reactivity towards electrophilic, nucleophilic and radical reagents, and even the carcinogenicity of novel heterocyclic analogues of fluoranthene (l), such as acenaphtho For example, Fig. 1 shows the relation, for analogous protons of 1 to 3, between 6, and free valence (F,), our chosen reactivity index, which gives predictions similar to many other indices,, and suggests correctly that electrophilic substitution (e.g. detritiation,13 bromination,14 nitrationl5 and sulphonation16) takes place preferentially at the 3 position for 1. The reactions of 2 and 3 have not apparently been studied. We believe, however, for a number of reasons that the basis of such correlations is, if not spurious, at least coincidental. We have already shown3 that if the range of protons of alternant benzenoid hydrocarbons is extended, substantial deviations from plots of 6, against F, occur which are not readily exp1ained.l' Even if these deviations are ignored, the remaining correlation arises as a fortuitous consequence of the geometry of polynuclear aromatic molecules, so that in a causative sense 6, is unrelated to F,.. Values of the latter fall into broad groups, each roughly corresponding to a different position type, e.g. relative proximity to ring centres, the values of 6, for the proton types of 4 are 6, > 6, > 6,, and for the protons of 1, 2 and 3, 6, e 6, > 6z;18*z0 apparent, but noncausatiue, relations between 6, and F, thus arise of the type shown in Fig. 1 , for which the correlation coefficient (0.87) is statisticazly significant at the 0.1 % level.* While contributions to 6, from unequal charge densities (q,, itself a reactivity index) are expected for nonalternants, hydrocarbon ions and heterocycles, 6, is still dominated by effects arising from .rr-electron circulations. A recent attemptz1 to argue a fundamental relation between a, , F, and q, depends on equating a general expression for the change in partial .rr-energy at the r'th atomic centre, (AE"), due to a general perturbation ( A m , = k,q, + k,F, + k...

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Reactivity parameters and aromatic systems. Part I. Detritiation rates in fluoranthene

Abstract: Rates of detritiation in trifluoroacetic acid have been measured for the five non-equivalent positions in the nonaiternant hydrocarbon fluoranthene. Rates a t 70.0" times 1 07k (sec.-l) for detritiation at each position are as follows: 1 -,

Cited by 6 publications

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Electrophilic Aromatic Substitution by the Fluorofullerene C₆₀F₁₈

Electrophilic Aromatic Substitution by the Fluorofullerene C₆₀F₁₈

ChemInform Abstract: REAKTIVITAETSPARAMETER UND AROMATISCHE SYST. 1. MITT. DETRITIIERUNGSGESCHWINDIGKEIT BEI FLUORANTHEN

Correlation of molecular orbital indices of reactivity and proton chemical shifts: Acenaphtho[1,2‐b]‐ and ‐[1,2‐c]thiophens

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Reactivity parameters and aromatic systems. Part I. Detritiation rates in fluoranthene

Abstract: Rates of detritiation in trifluoroacetic acid have been measured for the five non-equivalent positions in the nonaiternant hydrocarbon fluoranthene. Rates a t 70.0" times 1 07k (sec.-l) for detritiation at each position are as follows: 1 -,

Cited by 6 publications

References 0 publications

Electrophilic Aromatic Substitution by the Fluorofullerene C60F18

Electrophilic Aromatic Substitution by the Fluorofullerene C60F18

ChemInform Abstract: REAKTIVITAETSPARAMETER UND AROMATISCHE SYST. 1. MITT. DETRITIIERUNGSGESCHWINDIGKEIT BEI FLUORANTHEN

Correlation of molecular orbital indices of reactivity and proton chemical shifts: Acenaphtho[1,2‐b]‐ and ‐[1,2‐c]thiophens

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Electrophilic Aromatic Substitution by the Fluorofullerene C₆₀F₁₈

Electrophilic Aromatic Substitution by the Fluorofullerene C₆₀F₁₈