Perylene structure

The amine function in Pcs was also found to be versatile as it allows for the facile incorporation of other photoactive or electroactive species. In particular such amino-functionalized Pcs can be easily reacted with perylene dianhydride to undergo formation of the corresponding diimides such as 18 (Fig. 13) [90-92], The Pc building blocks, carrying either a spacered amino or an anilino group, respectively, were thus implemented into the perylene structure by melting of the two components in imidazole to result in the construction of the corresponding multicomponent assemblies. The pathway toward such structures can also be performed by first introduction of the phthalonitrile to the perylene followed by the formation of the macrocycle [93],... 

Wastes containing PAHs may be effectively destroyed by various incineration processes as mentioned briefly in the above section. Weber et al. (2001) have studied the mechanisms of formation of polychlorinated diben-zofurans (PCDF), polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN) and polychlorinated benzenes (PCBz) from the degradation of PAHs in two types of incinerators, the stoker type- and the fluidized bed incinerators. Their studies have revealed the occurrence of a sequence of steps, such as the cleavage of C-C bond in the PAHs, chlorination at these cleaved positions, further chlorination or oxygen insertion at the ortho positions to the chlorine atoms in the intermediate chlorinated species. A perylene structure in soot is proposed as the basis for the observed PCDF pattern in the fluidized bed incinerators. Polychlorinated dibenzo-dioxins (PCDD) and the polychlorinated... 

FIGURE 3.33 Illustration of the coloring of the perylene structure, respecting its most dense symmetrical (horizontal - middle) axis, following the Timisoara-Parma rule, as described in Figure 3.12 and Section 3.2.10.4 (Putz et al., 2013c). 

Figure 14-20. Molecular structure of naphthalene tctracarboxylic dianliydridc (NTCDA) and perylene letracarboxylic dianhydridc (PTCDA).

Emission spectra at these points are shown in Figure 8.2d. The band shapes were independent of the excitation intensity from 0.1 to 2.0 nJ pulse . The spectrum of the anthracene crystal with vibronic structures is ascribed to the fluorescence originating from the free exdton in the crystalline phase [1, 2], while the broad emission spectra of the pyrene microcrystal centered at 470 nm and that of the perylene microcrystal centered at 605 nm are, respectively, ascribed to the self-trapped exciton in the crystalline phase of pyrene and that of the a-type perylene crystal. These spectra clearly show that the femtosecond NIR pulse can produce excited singlet states in these microcrystals. 

Beton and co-workers extended the hydrogen bonding approach to two-component systems, generating a number of structures that utilise different molecular motifs.24 26 In the case of perylene tetracarboxylic diimide (PTCDI) co-adsorbed with melamine (1,3,5-triazine-2,4,6-triamine) on a silver-terminated silicon surface, a network is formed in which the straight edges correspond to PTCDI with melamine at the vertices (Figure 11.6). The network shows large-area pores that the authors used to trap heptamers of C6o molecules. 

Carbonyl pigments of a variety of types may also be classed as high-performance products. These include some anthraquinones, quinac-ridones, perylenes, perinones, isoindolines and diketopyrrolopyrroles. The chemistry of these groups of colorant is discussed in Chapter 4. Some representative examples of chemical structures of important high-performance carbonyl pigments are illustrated in Figure 9.4. 

Although organic anion radicals are oxygen sensitive, they have been isolated as crystalline salts from a variety of electron acceptors (e.g., chloranil, tetracyanoethylene, tetracyanoquinodimethane, perylene, naphthalene, anthracene, tetraphenylethylene, etc.) and their structures have been established by X-ray crystallography.180... 

Fig. 11 The scattering properties of a five branches - four electrodes molecular bridge, (a) Detailed atomic structure of the molecule. A central perylene branch was included to mimic an internal measurement branch, (b) EHMO-ESQC calculated T12(E) transmission coefficient (plain) and predicted T12(E) transmission coefficient (dashed), applying the intramolecular circuit rules discussed for the four molecular fragments given in Fig. 12. The dashed (dotted) line is the Ti2(E) variation for the single molecular branch, as presented in the inset, to show the origin of the destructive interference...

Attaching perylene moieties as side groups allows achievement of high concentration without affecting the electronic structure of the polymer backbone. Putting 16% perylene moieties as side chains predictably results in more efficient energy transfer, observed with polymer 360, both in solution and solid state (emission band at 599 nm). Although no PLED device with 360 has been reported, this material showed excellent performance in solar cells (external photovoltaic QE = 7%, in blend with PPV) [434]. 

SCHEME 3.43 Chemical structures of indeno[l,2,3- /]perylene and its derivatives. 

SCHEME 3.62 Chemical structures of blue perylene-based and biaryl-based emitters. 

Perylene (199) and its derivative (TBP, 200) have been widely used as blue dopant materials owing to their excellent color purity and stability. Efficient blue emitters with excellent CIE coordinates are found in biaryl compound 2,2 -bistriphenylenyl (BTP, 201) as shown in Scheme 3.62 [145]. A device of structure ITO/TPD/BTP/TPBI/Mg Ag emits bright blue emission with CIE (0.14, 0.11). A maximum brightness of 21,200 cd/m2 at 13.5 V with a maximum EQE of 4.2% (4.0 cd/A) and a power efficiency of 2.5 lm/W have been achieved. 

Jiang et al. were the first to report a relatively stable blue OLED based on anthracene derivative JBEM (120) [240]. With the similar OLED structure as that used above by Kodak of ITO/CuPc/NPD/JBEM perylene/Alq/Mg Ag and using JBEM as a blue host material, the device shows a maximum luminance of 7526 cd/m2 and a luminance of 408 cd/m2 at a current density of 20mA/cm2. The maximum efficiency is 1.45 lm/W with CIE (0.14,0.21). A half-life of over 1000 h at initial luminance of 100 cd/m2 has been achieved. The authors also compared the device performance using DPVBI as a host, which gave them a less stable device. 

The chemical classes of vat colours from which suitable pigments have been developed are anthraquinones, perinones, perylenes and thioindigos. Many vat dyes have been tested, but only about a dozen have met the stringent fastness standards demanded. Seven of those found suitable in all respects are shown in Table 2.1 and their chemical structures are given as 2.4 to 2.10. 

Owing to experimental difficulties, knowledge of aggregation effects in alkaline dithionite solutions of leuco vat dyes is sporadic [20,21]. Investigations based on absorption spectra have shown that, depending on concentration and temperature, planar polycyclic molecules such as the violanthrone derivatives Cl Vat Blues 19, 20 and 22 and the perylene tetracarboxydiimide derivatives Cl Vat Reds 23 and 32 are mainly present as monomers or dimers in leuco vat solutions. Violanthrones that do not have a coplanar structure because of the presence of... 

Most pigments derived from vat dyes are structurally based on anthraquinone derivatives such as indanthrone, flavanthrone, pyranthrone, or dibromoan-thanthrone. There are other polycyclic pigments which may be used directly in the form in which they are manufactured. This includes derivatives of naphthalene and perylene tetracarboxylic acid, dioxazine (Carbazole Violet), and tetrachloro-thioindigo. Quinacridone pigments, which were first introduced in 1958, and recently DPP pigments have been added to the series. 

There are publications describing black perylene pigments [4], These compounds are chemically closely related to the corresponding red species, from which they are derived through slight changes in the substitution pattern on the moiety X which is not part of the conjugated system (see structure 74). 

The perylene pigment in which X= )N-CH2-CH2-0-CH2-CH3, for instance, affords a red shade, while X= )N-CH2-CH2-CH2-OCH3 produces a black shade. The difference in shade is attributed to a structurally controlled special arrangement of the pigment molecules within the crystal lattice. 

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