Anthracene blue

The fact that dihydroxyanthraquinones can be directly oxidised to higher phenols with fuming sulphuric acid is of technical importance. Alizarin and quinizarin yield in this way the same 1 2 5 8-tetra-hydroxyanthraquinone (alizarin bordeaux), which can be further oxidised to the important compound anthracene blue (1 2 4 5 6 8-hexa-hydroxyanthraquinone). This dye is obtained technically from 1 5-or 1 8-dinitroanthraquinone by means of a very interesting reaction,... 

Alizarine red (S marks), Erweco alizarine acid red, alizarine orange S W, alizarine cyanine, brilliant alizarine cyanine, anthracene blue (S Marks), acid alizarine blue, alizarine dark green W, alizarine blue (S Marks), alizarine green A alizarine black S, alizarine indigo blue (S Marksl, coeruleine (S Marks). 0 n the addition of a few drops of dilute caustic soda (1 20), the colour becomes more 1 intense, and bluer ... 

Alizarine blue, alizarine cyanines or anthracene blues or Cr mordant. f p 1 SI at... 

A purified grade of anthracene (blue fluorescence, m.p. 216°) should be used. 

Optical fluorescence microscopy was employed to study the phase morphology of PVOH and PVAc blends [78]. Fluorescein (green) and anthracene (blue) were added to provide the contrast as fluorescein preferred the PVOH domains and anthracene concentrated in the PVAc domains. 

Naphthalene, CioHs, colourless solid, m.p. 80°, insoluble in water, soluble in alcohol, characteristic odour. Anthracene, CjH4 C2H2 CjH4, m.p. 216°, white crystals when pure, with a faint blue fluorescence, but often very pale yellow crystals insoluble in water, slightly soluble in alcohol. Phenanthrene, m.p. 98°, and biphenyl, m.p. 69°, are white solids. 

Purification of anthracene. Dissolve 0-3 g. of crude anthracene (usually yellowish in colour) in 160-200 ml. of hexane, and pass the solution through a column of activated alumina (1 5-2 X 8-10 cm.). Develop the chromatogram with 100 ml. of hexane. Examine the column in the hght of an ultra-violet lamp. A narrow, deep blue fluorescent zone (due to carbazole, m.p. 238°) will be seen near the top of the column. Immediately below this there is a yellow, non-fluorescent zone, due to naphthacene (m.p. 337°). The anthracene forms a broad, blue-violet fluorescent zone in the lower part of the column. Continue the development with hexane until fluorescent material commences to pass into the filtrate. Reject the first runnings which contain soluble impurities and yield a paraffin-hke substance upon evaporation. Now elute the column with hexane-benzene (1 1) until the yellow zone reaches the bottom region of the column. Upon concentration of the filtrate, pure anthracene, m.p. 215-216°, which is fluorescent in dayhght, is obtained. The experiment may be repeated several times in order to obtain a moderate quantity of material. 

Anthracen blau, n. aathraceoe blue, -farbstoff, m. anthracene dye. -81, n. anthracene oil. -pech, n. anthracene pitch. 

Anthracene, B. D. H. (blue fluorescence), was used. Traces of ethylene glycol, glycerol, ethanol, or water considerably retard the reaction and lead to unsatisfactory results. 

Figure 17.7 Electrocatalysis of O2 reduction by Pycnoporus cinnabarinus laccase on a 2-aminoanthracene-modified pyrolytic graphite edge (PGE) electrode and an unmodified PGE electrode at 25 °C in sodium citrate buffer (200 mM, pH 4). Red curves were recorded immediately after spotting laccase solution onto the electrode, while black curves were recorded after exchanging the electrochemical cell solution for enzyme-fiiee buffer solution. Insets show the long-term percentage change in limiting current (at 0.44 V vs. SHE) for electrocatalytic O2 reduction by laccase on an unmodified PGE electrode ( ) or a 2-aminoanthracene modified electrode ( ) after storage at 4 °C, and a cartoon representation of the probable route for electron transfer through the anthracene (shown in blue) to the blue Cu center of laccase. Reproduced by permission of The Royal Society of Chemistry fi om Blanford et al., 2007. (See color insert.)...

In complex organic molecules calculations of the geometry of excited states and hence predictions of chemiluminescent reactions are very difficult however, as is well known, in polycyclic aromatic hydrocarbons there are relatively small differences in the configurations of the ground state and the excited state. Moreover, the chemiluminescence produced by the reaction of aromatic hydrocarbon radical anions and radical cations is due to simple one-electron transfer reactions, especially in cases where both radical ions are derived from the same aromatic hydrocarbon, as in the reaction between 9.10-diphenyl anthracene radical cation and anion. More complex are radical ion chemiluminescence reactions involving radical ions of different parent compounds, such as the couple naphthalene radical anion/Wurster s blue (see Section VIII. B.). 

G. Klarner, M.H. Davey, E.-D. Chen, J.C. Scott, and R.D. Miller, Colorfast blue-light-emitting random copolymers derived from di-w-hexylfluorene and anthracene, Adv. Mater., 13 993-997, 1998. 

The most widely used fluorescent blue host materials are anthracene and distyryl-based compounds as shown in Scheme 3.38. These materials have good phase-compatibility with... 

Many large band-gap organic materials have been explored for blue emission. To summarize, they are the distyrylarylene series, anthracenes, perylenes, fluorenes, heterocyclic compounds, and metal complexes. 

Besides distyrylarylene as a blue host or dopant in blue OLED application, anthracene materials with high QE and emission color in the blue range make them attractive materials. 

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. 

Other derivatives have been reported such as the spiro-linked fluorene-anthracenes (126, 206), which preserve the optical and electrochemical properties of anthracene while reducing the tendency for crystallization and enhancing the solubility and Ts (Scheme 3.64). Highly efficient deep blue OLEDs have been demonstrated by using Spiro-FPAl (206) as an emitter material in a p-i-n type OLED structure ITO/MeO-TPD 2%F4-TCNQ/Spiro-TAD(44)/... 

By introducing the hole transport arylamine as an end cap for an anthracene backbone, Lin et al. designed a series of novel materials (207-212) (Scheme 3.65) [247]. The aim of these dual function materials is to combine the emitting property of the blue anthracene lumino-phore with the hole transport property of the triarylamine to simplify the device fabrication steps. Though the introduction of the arylamino moieties produces moderate QE (f 20%) for these materials, the OLEDs using them as emitters as well as HTMs demonstrate only moderate EL performance with a maximum luminance of 12,922 cd/m2 and 1.8 lm/W with CIE (0.15, 0.15). 

Qiu s group investigated the spirofluorene linked dihydroanthracene compound di-Spiro-9, 9 -di-fluorene-9",9" -(9,10-dihydro-anthracene) (DSFA), originally developed in the 1930s, as a blue emitter in ITO/m-MTDATA/NPD/DSFA/Mg Ag [258]. The device exhibited a... 

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