Perylene reaction

Our experiences with nitrite-ion reactions show that both nitration and oxygen-atom transfer can occur. Thus, 6 " and 10 give 2-nitrodibenzodioxin (12) and 3-nitroperylene (10) respectively according to eq. 6. The cation radical of zinc tetra-phenylporphyrin is similarly nitrated at one of the pyrrolic carbon atoms (44). The perylene reaction is so facile that it... 

Decomposition of diphenoylperoxide [6109-04-2] (40) in the presence of a fluorescer such as perylene in methylene chloride at 24°C produces chemiluminescence matching the fluorescence spectmm of the fluorescer with perylene was reported to be 10 5% (135). The reaction follows pseudo-first-order kinetics with the observed rate constant increasing with fluorescer concentration according to = k [flr]. Thus the fluorescer acts as a catalyst for peroxide decomposition, with catalytic decomposition competing with spontaneous thermal decomposition. An electron-transfer mechanism has been proposed (135). 

Hydrogen peroxide has also been analy2ed by its chemiluminescent reaction with bis(2,4,6-trichlorophenyl) oxalate and perylene in a buffered (pH 4—10) aqueous ethyl acetate—methanol solution (284). Using a flow system, intensity was linear from the detection limit of 7 x 10 M to at least 10 M. 

FIGURE 15.28 Chemiluminescence, the emission of light as the result of a chemical reaction, occurs when hydrogen peroxide is added to a solution of the organic compound perylene. Although hydrogen peroxide itself can fluoresce, in this case the light is emitted by the perylene. 

Tri-(l-naphthyl)phosphine is cleaved by alkali metals in THF solution. " Reaction with sodium gives the naphthalene radical-ion, with lithium the perylene radical-ion, and with potassium the radical-ion (22). Hydrocarbon radical-ion formation was thought to occur via naphthalene derived from the metal naphthalenide. E.s.r. spectra of further examples of phosphorus-substituted picrylhydrazyl radicals have been reported. ... 

Pitts JN Jr, B Zielinska, JA Sweetman, R Atkinson, AM Winer (1985b) Reactions of adsorbed pyrene and perylene with gaseous N2O5 under simulated atmospheric conditions. Atmos Environ 19 911-915. 

Perylenes (70) are diimides of perylene-3,4,9,10-tetracarboxylic acid, and may be prepared by reaction of the bis-anhydride of this acid, 89 (1 mol) with the appropriate amine (2 mol) in a high-boiling solvent as illustrated in Scheme 4.11. The synthesis of perinones 71 and 72 involves condensation of naphthalene-1,4,5,8-tetracarboxylic acid with benzene-1,2-diamine in refluxing acetic acid. This affords a mixture of the two isomers, which may be separated by a variety of methods, generally involving their differential solubility in acids and alkalis. 

Chemiluminescence also occurs during electrolysis of mixtures of DPACI2 99 and rubrene or perylene In the case of rubrene the chemiluminescence matches the fluorescence of the latter at the reduction potential of rubrene radical anion formation ( — 1.4 V) at —1.9 V, the reduction potential of DPA radical anion, a mixed emission is observed consisting of rubrene and DPA fluorescence. Similar results were obtained with the dibromide 100 and DPA and/or rubrene. An energy-transfer mechanism from excited DPA to rubrene could not be detected under the reaction conditions (see also 154>). There seems to be no explanation yet as to why, in mixtures of halides like DPACI2 and aromatic hydrocarbons, electrogenerated chemiluminescence always stems from that hydrocarbon which is most easily reduced. A great number of aryl and alkyl halides is reported to exhibit this type of rather efficient chemiluminescence 155>. 

A wide variety of different classes of fluorescent molecules has been investigated in the peroxyoxalate chemiluminescent systems. Among those screened were fluorescent dyes such as rhodamines and fluoresceins, heterocyclic compounds such as benzoxazoles and benzothiazoles, and a number of polycyclic aromatic hydrocarbons such as anthracenes, tetracenes, and perylenes. The polycyclic aromatic hydrocarbons and some of their amino derivatives appear to be the best acceptors as they combine high fluorescence efficiency with high excitation efficiency in the chemiluminescent reaction [28],... 

Another compound which loses R2E on irradiation is 30 (reaction 33), which forms perylene with the loss of Me2Sn53. The authors report no more than the basic details of the reaction, however. 

The customary method of preparing perylene pigments is by reaction of perylene tetracarboxylic dianhydride with primary aliphatic or aromatic amines in a high boiling solvent. The dianhydride itself is also used as a pigment. Di-methylperylimide may also be obtained by treating the diimide with methyl chloride or dimethyl sulfate. 

The primary starting material for the synthesis of perylene tetracarboxylic acid pigments is the dianhydride 71. It is prepared by fusing 1,8-naphthalene dicar-boxylic acid imide (naphthalic acid imide 69) with caustic alkali, for instance in sodium hydroxide/potassium hydroxide/sodium acetate at 190 to 220°C, followed by air oxidation of the molten reaction mixture or of the aqueous hydrolysate. The reaction initially affords the bisimide (peryldiimide) 70, which is subsequently hydrolyzed with concentrated sulfuric acid at 220°C to form the dianhydride ... 

Unsymmetrically substituted perylene pigments are a comparatively recent novelty. Selective protonation of the tetra sodium salt of perylene tetracarboxylic acid affords the monosodium salt of perylene tetracarboxylic monoanhydride in high yield. Stepwise reaction with amines produces unsymmetrically substituted perylene pigments [2],... 

Hirschler and Hudson (36/6), however, favor the opinion that Bronsted sites are exclusively responsible for the activity of silica-alumina. In studying the adsorption of perylene and of triphenylmethane, they concluded that carbonium ions are not formed by a hydride abstraction mechanism as claimed by Leftin (362). Instead, triphenylmethane is oxidized by chemisorbed oxygen to triphenylcarbinol in a photo-catalyzed reaction, followed by reaction with a Bronsted acid giving water and a triphenylmethyl carbonium ion. After treatment with anhydrous ammonia, the organic compound was recovered by extraction as triphenylcarbinol. About thirteen molecules of ammonia per assumed Lewis site were required to poison the chemisorption of trityl ions. The authors explain the selective inhibition of certain catalyzed reactions by alkali by assuming that only certain of the acidic protons will ion-exchange with alkali ions. 

Nentral perylene reacts with N02, giving the cation-radical. Flowever, its formation is, in principle, a result of a-complex splitting. Another possible route of a-complex splitting consists of proton elimination and nitro perylene formation. As experiments show, the nitration of perylene is accompanied with collateral reactions of PerH, such as recombination and interaction with solvent molecules (Eberson and Radner 1985). This testifies to the release of cation-radical. 

Cation-radicals of naphthalene and its homologues, pyrene, or perylene react with NOj" ion in AN, giving electron-transfer products, that is, ArH and NOj. The latter radical is not very active in these reactions and nitration takes place only with extremely reactive compounds such as perylene (Eberson and Radner 1985, 1986). This mechanism is seemingly distinctive of compounds with E° less or equal to 1 V in AN (or in other solvents solvating NOj ions sparingly). 

In a different study, anthracene, phenanthrene, perylene 93 (Fig. 31), and 2,7-di-tert-butylpyrene underwent regioselective oxidative-substitution reactions with iodine(III) sulfonate reagents in dichloromethane to give the corresponding aryl sulfonate esters. The use of [hydroxy(tosyloxy)iodo]benzene, in conjunction with trimethylsilyl isothiocyanate, led to thiocyanation of the PAH nucleus. 

The comparison of PTCDA with its parent perylene molecule is extremely interesting. For perylene MLs on Ag(l 11), electron diffraction suggests an orientational liquid, in which the molecules are positionally ordered in an incommensurate close-packed superlattice but orientationally disordered and mobile. The same activated Raman peaks as for PTCDA are observed but they are, however, orders of magnitude weaker, indicating that, while a molecular reaction centre may still exist in the perylene backbone, its residual activity would be too small for the molecule to recognize a preferred site. 

The main features of the chemiluminescence mechanism are exemplarily illustrated in Scheme 11 for the reaction of bis(2,4,6-trichlorophenyl)oxalate (TCPO) with hydrogen peroxide in the presence of imidazole (IMI-H) as base catalyst and the chemiluminescent activators (ACT) anthracene, 9,10-diphenylanthracene, 2,5-diphenyloxazole, perylene and rubrene. In this mechanism, the replacement of the phenolic substituents in TCPO by IMI-H constitutes the slow step, whereas the nucleophilic attack of hydrogen peroxide on the intermediary l,l -oxalyl diimidazole (ODI) is fast. This rate difference is manifested by a two-exponential behavior of the chemiluminescence kinetics. The observed dependence of the chemiexcitation yield on the electrochemical characteristics of the activator has been rationalized in terms of the intermolecular CIEEL mechanism (Scheme 12), in which the free-energy balance for the electron back-transfer (BET) determines whether the singlet-excited activator, the species responsible for the light emission, is formed ... 

Lee and coworkers postulated the involvement of 50 and 51 (Ar = 2,4-dinitrophenyl) as two HEIs formed in parallel in the uncatalyzed reaction of DNPO and hydrogen peroxide in the presence of perylene. Due to the experimental observations of light emission from the reaction of DNPO and TCPO also in the absence of hydrogen peroxide, Lee and coworkers postulated the involvement of a nonperoxidic HEI (additionally to 51 and 3, 48 or 52) under these conditions. However, neither chemiluminescence quantum yields nor even relative emission intensities have been reported. Furthermore, it was shown " that the intensities and the chemiluminescence quantum yields in the absence of hydrogen peroxide are five orders of magnitude lower than in the presence of 10 M H2O2, indicating that the proposed additional pathway is of extremely low efficiency for excited-state... 

The peroxyoxalate system is the only intermolecular chemiluminescent reaction presumably involving the (71EEL sequence (Scheme 44), which shows high singlet excitation yields (4>s), as confirmed independently by several authors Moreover, Stevani and coworkers reported a correlation between the singlet quantum yields, extrapolated to infinite activator concentrations (4> ), and the free energy involved in back electron-transfer (AG bet), as well as between the catalytic electron-transfer/deactivation rate constants ratio, ln( cAx( i3), and E j2° (see Section V). A linear correlation of ln( cAx( i3) and E /2° was obtained for the peroxyoxalate reaction with TCPO and H2O2 catalyzed by imidazole and for the imidazole-catalyzed reaction of 57, both in the presence of five activators commonly used in CIEEL studies (anthracene, DPA, PPO, perylene and rubrene). A further confirmation of the validity of the CIEEL mechanism in the excitation step of... 

BaP, benzo[g/z/]perylene, benzo[6]fluoranthene, in-deno[l,2,3-cd]pyrene, and benzo[/c]fluoranthene, contribute the major portion of the identifiable mutagenicity of the extract of the whole unfractionated sample, accounting for 8.6, 2.5, 1.7, 1.4, 1.2, and 0.8%, respectively, of the total mutagenicity of the whole sample. Two semipolar mutagenic PACs were also present at significant levels 2-nitrofluoranthene, a product of atmospheric reactions, and 6//-benzo[c<7]pyren-6-one, a primary O-PAC pollutant present in exhaust emissions from diesel engines and non-catalyst-equipped cars (see Sections E and F). These account for an additional 0.8 and 1.6%, respectively, of the identified whole sample mutagenic potency (see Table 10.26). 

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