Anthracene derivatives

Ring formation readily occurs ia the alkylation of aromatics with di- and polyhaUdes, eg, the reaction of di- and ttihalomethanes with aromatics ia the presence of aluminum chloride. In the reaction of dichioromethane and ben2ene, besides diaryknethanes, anthracene derivatives are also formed (54). 

Russell et al. Anal Ghent 50 2961 1986.] The material was free from anthracene derivatives. Another purification step involved passage of pyrene in cyclohexane through a column of silica gel. It can be sublimed in a vacuum and zone refined. [Kano et al. J Phys Ghent 89 3748 1985.]... 

Using the powdered drugs, almost 90% of the anthracene derivatives are found in the tea, while with coarsely chopped drugs only ca. 30% [9]. 

Note The natural fluorescence colors of some flavonoids [7, 9] and anthracene derivatives [16] are altered by the ammonia treatment. This makes possible differentiation on the basis of color. Detection limits per chromatogram zone have been reported of 2 ng for morphine and heroin [2], 6 ng for ochratoxin A [5] and 1 pg for penicillic acid [13]. 

Early methods of following the reaction relied upon quantitative recovery of the anthracene derivative from the reaction mixture and in view of the extreme insolubility of these derivatives, this is one of the few reactions that can be accurately studied by product recovery methods. More recently, of course, the uv spectroscopic method has been used, the formation of the anthracene spectrum with time being measured. 

Naphthalene has been used as a moth repellant and an insecticide, but these uses are decreasing due to the increasing use of para-dichlorobenzene instead. Derivatives of naphthalene are used in dyes and drugs. An example of the latter is the pain reliever naproxen (sold in drugstores as Aleve ). Some anthracene derivatives are also used as dyes. 

The rate constants for a number of anthracene derivatives in various solvents are given in Table 2.11. A number of common points can be seen. 

Another explanation has been offered to explain the large proportion of cyclobutane derivatives produced by low-energy sensitizers, especially for the anthracene derivatives.<17) This is that energy transfer to diene occurs from the second excited triplet state of the sensitizer rather than the first. Experiments using a large number of anthracene derivatives as sensitizers... 

Data for various anthracene derivatives are given in Table 2.2.<7,8>... 

In the case of the photoaddition of anthracene derivatives and tetracene, the cross-dimer is the major product isolated in all cases even when anthracene itself is used. 

Table 10.2. Photosensitization of Butadiene Dimerization Using Anthracene Derivatives as Sensitizersar>...

DA reactions with polycyclic hydrocarbon derivatives have also been applied to other macrocycles. Lukyanets and coworkers have explored this methodology by adding the unsubstituted tetraazaporphine 20 to a series of anthracene derivatives (Scheme 6). For instance, the reaction with naphthacene (after 6 h at reflux) afforded the chlorin 21 and a tetraazabacteriochlorin (bisadduct) in small amounts <00JPP525>. 

Table I. Effect of a Methyl Group at a Single Starred Position on Carcinogenic Activity of Benz[a]anthracene Derivatives...

Similarly, the use of a higher input power in retro-Diels-Alder reactions of anthracene derivatives has been reported to afford complete reaction in 3-5 min [36], This method is an alternative to the use of flash thermolysis. The use of graphite is a prerequisite for obtaining high temperatures in a short time. 

As reported by T. Wilson 71>, the emitter is the anthracene derivative 9 which can be replaced by rubrene, but not by 9.10-diphenylanthracene. 

The oxidative ring cleavage undergone by purpurogallin quinone 14 is assumed to provide the excitation energy necessary to cause the tropolones to act as fluorescers. Perhaps dioxetane derivatives are key intermediates, as in the anthracene derivatives discussed in (IV. D.). 

Aminoanthracene forms a Schiff base with dimethylacetaldehyde (isobutyral-dehyde). This compound can be oxidized by peroxide under basic conditions to form 9-formamidoanthracene and acetone in dimethylformamide as a solvent [54, 55], CL from this system can be observed in other aprotic solvents as well. A limited amount of work has been done with the CLs of Schiff bases or anthracene derivatives. Presumably, this will change in the future. 

An application of this reaction to aromatic ring extension is noteworthy. As shown in Eq. 2.43, zirconacydopentadienes couple with diiodobenzene (63) to afford naphthalenes 64. When tetraiodobenzene (65) is used, octasubstituted anthracene derivatives 66 are obtained [7c],... 

In realizing the poor film-forming property of 9,10-(diphenyl)anthracene, the Kodak group improved this property by designing a series of blue emitters based on further substituted anthracene derivatives. The chemical structures of these materials were patented in a U.S. Patent in 1999 [239], In their patent, Kodak also reported the EL data using one of these compounds as a host material and using TBP as a blue dopant (Scheme 3.62). The device structures is ITO/CuPc/NPD/anthracene compounds.5%TBP/Alq3/Mg Ag. The EL of the device showed blue emission with CIE color coordinates of (0.144, 0.196). Without the... 

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. 

Several groups have studied naphthalene substituted anthracene derivatives as hosts or emitter materials in blue OLEDs (121, 202-205) (Scheme 3.63). The Kodak group used ADN as a host and TBP as a dopant in ITO/CuPc/NPD/ADN TBP/Alq3/Mg Ag [241]. They achieved a narrow vibronic emission centered at 465 nm with CIE (0.154, 0.232) and a luminescent efficiency as high as 3.5 cd/A. In comparison, the undoped device shows a broad and featureless bluish-green emission centered at 460 nm with CIE (0.197, 0.257) and an EL efficiency below 2.0 cd/A. The operational lifetimes of the doped device and the undoped device were 4000 and 2000 h at an initial luminance of 636 cd/m2 and 384 cd/m2, respectively. 

X. Jiang, Z. Zhang, X. Zheng, Y. Wu, and S. Xu, A blue organic emitting diode from anthracene derivative, Thin Solid Films, 401 251-254 (2001). 

J. Shi and C.W. Tang, Anthracene derivatives for stable blue-emitting organic electroluminescence devices, Appl. Phys. Lett., 80 3201-3203 (2002). 

The residue can be minimized using bilayer schemes and sensitivity can be increased by either using poly(vinyl biphenyl) derivatives that are more absorbing at 248 nm or by adding anthracene derivatives to chlorinated poly(styrene) polymer. The present formulations are not production worthy because of this residue and we are currently working on approaches that may eliminate this problem. 

Figures 1-3 show deep UV transmittance (248 or 260 nm) for several different anthracene derivatives inpoly(phenylsilsesquioxane) (PPSQ), with and without an external triplet sensitizer (Kc450, or "Kc"). It is clear that there are substantial differences in the bleaching contrast.

---