Perylene, preparation

Reagents. Perylene was obtained from Sigma Chemical Company (St. Louis, Missouri). All other PAHs were supplied by Aldrich Chemical Company (Milwaukee, Wisconsin) and were reported to contain less that 3% impurities. All PAHs were used without further purification. Isopropyl ether (99%) for extraction work was also purchased from Aldrich. Hydroquinone, a fluorescent stabilizer present in the ether, was removed prior to solution preparation by rotary evaporation. Fluorometric-grade 1-butanol was supplied by Fisher Scientific Company (Fair Lawn, New Jersey). All solutions for extractions of PAHs were prepared by evaporating portions of a stock cyclohexane solution and diluting to the appropriate volume with isopropyl ether. Fluorescence measurements were performed on 1 10 dilutions of the stock and final organic phase solutions. The effect of dissolved CDx on the fluorescence intensity of the organic phase PAH was minimized by dilution with isopropyl ether. 

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. 

Rosseinsky, D. R. et al., J. Chem. Soc., Perkin Trans. 2, 1985, 135-138 The title compound, prepared by electrolysis of perylene and tetrabutylammo-nium perchlorate in nitrobenzene, exploded on contact with nickel. Co-produced compounds should also be handled with caution and in small amounts, especially in contact with metals. 

One of the most commonly studied systems involves the adsorption of polynuclear aromatic compounds on amorphous or certain crystalline silica-alumina catalysts. The aromatic compounds such as anthracene, perylene, and naphthalene are characterized by low ionization potentials, and upon adsorption they form paramagnetic species which are generally attributed to the appropriate cation radical (69, 70). An analysis of the well-resolved spectrum of perylene on silica-alumina shows that the proton hyperfine coupling constants are shifted by about four percent from the corresponding values obtained when the radical cation is prepared in H2SO4 (71). The linewidth and symmetry require that the motion is appreciable and that the correlation times are comparable to those found in solution. 

Synthesis of Radical Cation Perchlorates and Subsequent Coupling with NucleophilesT Syntheses of the radical cation perchlorates of BP and 6-methylBP (12) were accomplished by the method reported earlier for the preparation of the perylene radical cation (13,14). More recently we have also synthesized the radical cation perchlorate of 6-fluoroBP (15). Oxidation of the PAH with iodine in benzene in the presence of AgClO. instantaneously produces a black precipitate containing the radical cation perchlorate adsorbed on Agl with... 

Since the discovery of the first organic semiconductor perylene-bromine complex in 1954 [1], a large number of molecular conductors, including more than 100 molecular superconductors, have been prepared. Conducting molecular materials are characterized by the following features ... 

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 ... 

The dianhydride of perylene tetracarboxylic acid is converted into the pigment form by preparing the corresponding alkali salt and then reprecipitating the compound with an acid. The dianhydride is formed after separating the acid by thermal aftertreatment at 100 to 200°C, possibly under pressure, with an organic solvent. The list of suitable media includes alcohols, ketones, carboxylic acid esters, hydrocarbons, and dipolar aprotic solvents. 

Perylene tetracarboxylic acid dimethylimide may also be prepared by methylating the corresponding diimide. 

Some fimctionalized materials have also been prepared by coprecipitation at low supersaturation. A perylene chromophore, for example, has been intercalated into LDH in an attempt to prepare stabihzed pigments [40]. Catalyt-ically active species have also been introduced into the interlayers of LDHs by direct synthesis, e.g. the intercalation of (PWi204o) or (SiWi204o) gives catalysts or catalyst precursors containing interlayer polyoxometalate anions [41]. Vein et al. reported the synthesis of Zr-containing LDH-Hke... 

Stevani and coworkers prepared and characterized a peracid intermediate, 4-chloro-pheny 1-0,0-hydrogen monoperoxalate (57) and found that no chemiluminescence was observed in the presence of activators (i.e. rubrene, perylene and DPA) and the absence of a base. Based on this result, the authors excluded 57 and similar peracid derivatives as HEI in the peroxyoxalate system. Moreover, 57 only emits light in the presence of an activator and a base with pK > 6, suggesting that a slow chemical transformation must still occur prior to the chemiexcitation step. Kinetic experiments with 57, using mainly imidazole, but also in the presence of other bases such as potassium 4-chlorophenolate, f-butoxide and l,8-bis(dimethylamino)naphthalene , showed that imidazole can act competitively as base and nucleophilic catalyst (Scheme 41). At low imidazole concentrations, base catalysis is the main pathway (steps 1 and 2) however, increasing the base concentration causes nucleophilic attack of imidazole catalyzed by imidazole to become the main pathway (steps la and 2a). Contrary to the proposal of Hohman and coworkers , the... 

A typical example involves the perylene monoimide donors described above. They have been used to construct antenna models in which up to eight perylene units were covalently bound to a zinc(II) porphyrin94. Osuka and coworkers windmill porphyrins also present excellent antenna complex building blocks (vide infra)95. In addition, several porphyrin wheel antenna complexes were prepared by template-assisted synthesis96,97 or self-aggregation98. Intramolecular cyclization of porphyrin dodecamers to a porphyrin wheel has also been achieved99. 

The perylene chromophotes were modified by covalently attaching different side groups. Two bulky groups (tertiary-butyl), indicated by a prime, prevented dimerization of neighbouring perylene chromophores when attached to the surface. Linkage to the semiconductor was achieved by different anchor-cum-spacer groups carbonic acid (-COOH) [4], propionic acid (-CH2-CH2-COOH) [2], phosphonic acid (-P(0)(OH)2) [4], methyl-phosphonic acid (-CH2-PO(OH)2) [2] and a -Tripod (see inset in Fig.2) [5], The preparation and sensitization of the nano-structured TiC>2 film and further experimental details have been described before [2]. 

Perylene bisimide-dithienothiophene derivatives have been prepared (09JPC(A)5039). A femtosecond transient absorption study showed the presence of two positive bands at 490 nm (perylene cation radical) and at 730 nm (perylene anion radical). 

The crystalline composites obtained between poly(3-alkylthiophene) and polystyrene showed an enhanced conductivity (07MM6579). The preparation of regioregular poly(3-alkylthiophene) and perylene diimide derivatives composites have been reported (06MI384). The photoluminescence spectra of this type of composites exhibit a significant photoluminescence quenching of the perylene diimide derivative. This result implies that the light absorbed by the perylene diimide units could also contribute to the generation of current at the photovoltaic device. 

Similarly, Torres et al. also reported the preparation of perylene-Pc assemblies 5 (Fig. 5). The synthesis of these triads was thereby accomplished via palladium-catalyzed cross-coupling pursuing two different routes [46], First preparing the perylenediimide with two bromine units in positions 1 and 7 and subsequent... 

Precursor family 27 with a perylene sub-unit were prepared due to their fluorescent properties and their photostability. Grafting of the perylene unit with —(CH2)3Si(OR)3 arms (Section m.B) allows their solubility to be increased and thus to prepare materials... 

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