Acenaphthylene, addition

On the other hand, addition of DBr to acenaphthylene (5) and to indene and 1-phenylpropene gave predominant syn addition. ... 

However, there are also many systems in which the evidence indicates that the propagating species cannot be a carbenium ion. Such reactions have been termed pseudo-cationic and in these polymerisations the propagating species is believed to be an ester. The most thoroughly investigated systems comprise aromatic monomers (styrene, acenaphthylene [11]) and protonic acids (HC104) or iodine [11] as initiators. The simplest representation of the propagation is as the addition of the ester (stabilised by four styrene molecules) across the double-bond of the monomer [12] ... 

Hamaguchi and Nagai (65,66) generated oxamiinchnones 109 as described in Section 10.1.7. They find that in addition to a cycloaddition with DMAD (Scheme 10.20), these oxamiinchnones react with acenaphthylene, maleimides, phenylacetylene, and dibenzoylacetylene to afford 335-338, respectively, in good yields (65,66). In the case of 335 and 336 the exo/endo ratio varies from 3 2 to 5 1 depending on the substituents. 

PAHs photooxidized by the type II singlet oxygen mediated mechanism include acenaphthylene, whose oxidized products and yields are shown in Fig. 10.29B (Barbas et al., 1994), phenanthrene (Barbas et al., 1996), anthracene (Dabestini et al., 1995), and tetracene (Dabestini et al., 1996). An additional photochemical process, the formation of photodimers, is also observed for acenaphthylene, anthracene, and tetracene. 

Photochemical cycloaddition of cyclohex-2-ene-l,4-dione (31) and acenaphthylene (32) in dichloromethane gives the iM-,un//,c -adduct 33 in 15% yield, in addition to large amounts of acenaphthylene dimers, which are insoluble and precipitate during the photolysis.100... 

The hydrogen fluoride catalyzed fluorine addition to acenaphthylene and 1,2-dihydronaph-thalene by xenon difluoride results (predominantly via ami attack) in the formation of vicinal difluorides ( 70% yield).37 Phenyl-substituted cycloalkenes 5 (n = 1-3) form the appropriate difluorides the configuration being dependent on ring magnitude.38... 

The silver(I) fluoride/bromine and silver(I) fluoride/iodine systems can be exploited for generation in situ and electrophilic addition of "bromine monofluoride and iodine monofluoride to cyclohexene, mcthylenecyclohcxane, styrene, indene, and acenaphthylene.55... 

The reaction of phenyl-substituted alkenes (2-phenylprop-l-ene, ( )-l-phenylprop-l-ene, 1,1-diphenylethene, 1,1-diphenylprop-l-ene) with F-Teda BF4 (6) in the presence of various alcohols results in the formation of vicinal fluoro alkoxy adducts with Markovnikov-type regioselec-tivity.89,94 The stereochemistry of the fluorination-methoxylation addition reaction is slightly syn predominant in the case of (Z)-stilbene, indene, and dibenzosuberenone, while equal amounts of both diastereoisomers are formed in the case of ( )-l-phenylprop-l-ene and acenaphthylene. 

The rate of dehydrocyclization increase with the number of aromatic rings in the molecule (19). The dehydrocyclization of alkylnaphthalenes can follow the same pathways as the cyclization of alkylbenzenes C5-dehydro-cyclization gives benzindans and benzindenes, while C6-dehydrocyclization yields anthracenes and phenanthrenes. In addition to these two pathways, a-substituted alkylnaphthalenes can cyclize to acenaphthenes and acenaphthylenes ... 

Related complexes of group 10 metals are accessible by an oxidative addition/reductive cyclization protocol, exploiting the inverse electron demand (Scheme 27) (Pt <2005JA13494>, Ni <20030M3604>). The nickel complex is thermally unstable, proceeding to perylene via a bimolecular reductive elimination or, in the presence of alkynes, delivering acenaphthylene derivatives by an insertion/reductive elimination pathway. 

In the HMO if> of styrene, the coefficients at the a and / carbon atoms are ca. 0-4 and 0-6 respectively. In the HMO ifi7 of acenaphthylene, the coefficients at carbon atoms 1 and 2 are ca. — 032 and 0-32. Therefore, the directive effect for addition is syn in styrene and anti in acenaphthylene Second, MO calculations may be helpful in new or different systems. With respect to eliminations, Fukui and Fujimoto (1965) used frontier electron theory to provide reactivity indices for two model... 

Cabaleiro and Johnson (1967) report that the addition of chlorine to -methyl cinnamate in chloroform or acetic acid is syn-selective, SS 0-75, in chloroform and acetic acid acetoxychloro derivatives are produced as well. Again, Dewar and Fahey (1964) argue that the normal course of addition of hydrogen halides onto olefins is a polar electrophilic process involving classical carbonium ions as intermediates and leading mostly but not exclusively to cis-adducts. A syn-preference was found in the additions of deuterium bromide to acenaphthylene, indene, and cis- and fraws-phenylpropene. In the case of indene, phenylpropene and methyl cinnamate, which are styrene analogs, concerted syn addition is symmetry-allowed (see bottom of p. 273). 

Effects of aromatic additives on the radiation resistance may be summarized as followed. Addition of acenaphthylene or acenaphthene provides an effective... 

Fig. 18a, b. A schematic model of the dispersion of the aromatic additives in polymer matrix, a) Acenaphthene system acenaphthene (At) and reaction products between aromatic fragment radicals from crosslinking agent and the naphthalene ring of the additives (Xn) dispersed in polymer chains, b) Acenaphthylene system acenaphthylene (Ay) and Xn molecules are fixed to polymer chains [88]... 

At acenaphthylene concentrations as low as 2 10 m, facile photodimerization takes place in benzene in the presence of nonionic or anionic surfactants, whereas in pure benzene at these concentrations no detectable amount of the two dimers is found [720]. Furthermore, the cis/trans product ratio is slightly dependent on the type of surfactant used [720, 721]. The product ratio during the course of photodimerization of 1-substituted acenaphthylenes is influenced by both solvent polarity and the addition of... 

Using ammonium cerium(IV) nitrate (CAN) as the oxidant for the azide anion, the azido radicals are trapped by alkenes, to form, ultimately, /i-azido nitrates84 cerium azide species may be considered as intermediates. Alkenes conjugated with carbonyl groups are recovered intact. The stereochemistry of the adducts from acenaphthylene and indene was trans, as shown by H-NMR studies (/AX < 2 Hz for the acenaphthylene adduct), but with (-Eyi-phenyl-l-propene both syn and anti additions were formed. 

The interaction of HCl and HBr with indene in methylene chloride and with acenaphthylene in pentane, methylene chloride and acetic acid as well as the reaction of HI with the latter monomer in methylene chloride only yielded the addition products, no polymerisation being detected. However, according to older reports the dimers of both these monomers can be obtained with HCI . Whatever the reason for this discrepancy, it is obvious that indene and acenaphthylene fall in the same category as styrene in that they do not offer the best conditions for the formation of active species in reacting with hydrogen halides. It would be interesting to try these interactions in more polar solvents. 

SimOar work was carried out by Giusti s group on acenaphthylene and the same mechanistic conclusions were reached. The lack of effect of hi electric fields applied to the polymerising solutions was an additional element in favour of pseudocationic propagation. 

The six collected fractions were extracted by soaking them in methylene chloride for 18 hours in a soxhlet apparatus after the addition of deuteiated PAHs surrogate standard (acenaphthylene dg, pyrene dio and benzo(a]pyrene dn). 

Bridging is defined as the insertion of additional n centers within the perimeter. Examples are the production of acenaphthylene (16) from the [ll]annulenium cation and a C fragment or the production of pyrene (17) from [14]annulene and the C=C ethylene unit ... 

AHOMO and ALUMO may be derived from a perturbational treatment of the union of the [I l]annulenyl cation and C or of the [I3]annulenide anion and C , respectively. This also shows that these molecules have further excited states in addition to those derived from a (4N + 2)-electron perimeter. This is true for the longest-wavelength transitions of both molecules, which therefore cannot be labeled within the framework of Platt s nomenclature. Hence, a prediction of their MCD sign on the basis of the perimeter model is also impossible. However, the next two bands correspond to the L, and Lj states of a (4Af + 2)-electron perimeter and show the expected behavior in the MCD spectra. In acenaphthylene the order of the B terms is -, + and in pleiadiene -f-, -. These signs are not changed by perturbing substituents since the difference between AHOMO and ALUMO is too large. Both molecules represent hard chromophores. 

In the absence of an additive, tritylsodium polymerizes acenaphthylene (5). When the reaction is carried out in the presence of triphenylaluminum the reaction... 

PAHs1 NA 0.6 mg/kg/day (intermediate, acenaphthene) 0.4 mg/kg/day (intermediate, fluoranthene fluorene) 10 mg/kg/day (intermediate, anthracene) Group 2A benz(a)anthracene, benzo(a)pyrene Group 2B benzo(b)fluoranthen e benzo(j)fluoranthene, ideno(1,2,3-c,d) pyrene Group 3 anthracene, benzo(g,h,i)perylene, additional PAHs Group B2 benz(a)anthracene, benzo(b)fluoranthene, benzo(a)pyrene, chrysene, dibenz(a,h)- anthracene, indeno(1,2,3-c,d)- pyrene Group D acenaphthylene, anthracene, fluoranthene... 

Polycyclic systems bearing more than one negative charge present two problems, (a) The early method of studying ion-pairing of monoanions failed as the UV-Vis measurements have limitations which arise from difficulties in distinguishing between discrete ion-pair states in systems with extended ir-conjugation K2). In such cases a situation may occur where one cation is solvated while the other one appears as a c.i.p. Due to the limited time scale of the optical methods, no distinction could be made between the two species, (b) The mutual location of the cations presents an additional problem. The description of the system itself is complicated due to Coulomb repulsions between the cations. The ion-solvation equilibria of dibenzo[b,f]pentalene dianion (32 ) (dibenzopentalenide) 82>, its 5,10-dimethyl derivative (72-), and acenaphthylene dianion (82 )S3) have been studied in detail. 

The mechanism of the electron transfer-sensitised dimerisation of acenaphthylene (188) has been studied in considerable detail. Two dimers (189) and (190), formed from the radical cation of acenaphthylene, are obtained in addition to (191) and (192) which incorporate the TCNE sensitiser. Fumaroni-trile behaves in a similar fashion yielding the dimers (189) and (190) as well as cycloadducts. A study of the energetics of electron transfer in acenaphthylene charge transfer photochemistry has been carried out. ... 

A remarkable photochemical [2 -I- 2] addition of acenaphthylene and tetracyanoethylene in neat to produce the corresponding cycloadduct (Scheme 5.51) has been reported by Haga et al2 Interestingly, this reaction was inert in the presence of solvent. 

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