Yellow chemical structures

The optical properties can be tuned by variations of the chromophores (e.g. type of side-chains or length of chromophorc). The alkyl- and alkoxy-substituted polymers emit in the bluc-gnecn range of the visible spectrum with high photolu-inincsccncc quantum yields (0.4-0.8 in solution), while yellow or red emission is obtained by a further modification of the chemical structure of the chromophores. For example, cyano substitution on the vinylene moiety yields an orange emitter. 

Because luciferyl adenylate emitted a red chemiluminescence in the presence of base, coinciding with the red fluorescence of 5,5-dimethyloxylucferin, the keto-form monoanion Cl in its excited state is considered to be the emitter of the red light. Thus, the emitter of the yellow-green light is probably the enol-form dianion C2 in its excited state, provided that the enolization takes place within the life-time of the excited state. Although the evidence had not been conclusive, especially on the chemical structures of the light emitters that emit two different colors, the mechanism shown in Fig. 1.12 was widely believed and cited until about 1990. 

The color index (Cl) number, developed by the society of dyers and colorists, is used for dye classification. Once the chemical structure of a dye is known, a fivedigit Cl number is assigned to it. The first word is the dye classification and the second word is the hue or shade of the dye. For example, Cl Acid Yellow 36 (Cl 13065) is a yellow dye of the acid type. Additionally, a dye mixture may consist of several dyes for example, Navy 106 is composed of three reactive azo dyes remazol black B (Reactive Black 5), Remazol Red RB (Reactive Red 198), and Remazol Golden Yellow 3. 

Commercially significant diarylide yellow pigments have the following chemical structure ... 

The same chemistry is involved as with monoazo yellow pigments, except that (3-naphthol pigments are obtained by coupling with 2-hydroxynaphthalene ((3-naph-thol) instead of acetoacetarylides. They have the general chemical structure ... 

Two possible chemical structures have been found for yellow disazo condensation pigments. The two monoazo units may be connected either via the coupling component (type 1) or via the diazo moiety (type 2). 

Recent developments in this class prefer azomethine complexes as chemical structures rather than azo metal complexes. The list of commercially available types includes Pigment Green 8 and 10, Pigment Yellow 117,129,150,153,177,179, and Pigment Orange 59,65, and 68, as well as P.R.257. 

Among heterocyclic substituted 1-aminoanthraquinone derivatives, the 2 1 reaction product with 1-phenyl-2,4,6-triazine, also referred to as Pigment Yellow 147,60645, should be mentioned as an example [10]. It is a reddish yellow pigment with the chemical structure 87 ... 

Flavanthrone Yellow, together with its chemical structure, is listed in the Colour Index under Constitution No. 70600. It was temporarily known as Pigment Yellow 112, but now it is exclusively referred to as Pigment Yellow 24. Since some time sales products of P.Y.24 are not listed anymore in the catalogues of the manufacturers, but the grades are still available on the market. 

Pigment Yellow 138,56300, has the chemical structure 138 with X = C1 [4], The synthesis of halogenated compounds (138), for instance P.Y.138, can also be achieved by stepwise heating of tetrachloro phthalic anhydride and 8-amino-chinaldine in molten benzoic acid from 125 to 140 and then to 160°C [5],... 

The chemical structure of P.Y.148, a greenish yellow pigment is listed in the Color Index under Constitution Number 59020 ... 

Pigments with Hitherto Unknown Chemical Structure 579 Pigment Yellow 201... 

The success of the carotenoid extracts led to the commercialization of synthetic carotenoids, some with the same chemical structure as those in the plant extracts and others with modifications to improve their technological properties. The yellow beta-carotene was synthesized in 1950, followed by the orange beta-8-carotenal in 1962 and the red canthaxanthin in 1964. A number of others soon followed, methyl and ethyl esters of carotenoic acid, citraxanthin, zeaxanthin, astaxanthin, and recently lutein. 

Fig. 18 Chemical structure of (a) PTAA, (b) PONT and (c) POMT. (d, e) Fluorescence images of amyloid deposits in tissue stained by PTAA. PTAA bound to amyloid deposits (white arrows) emits light with a yellow-red, color [33]...

MEKC has been applied for the study of the effect of Monascus pigments on the decomposition of the mutagenic 3-hydroxyamino-l-methyl-5H-pyrido[4,3-b]indole (Trp-P-2(NHOH)). The chemical structures of yellow and red pigments are shown in Fig. 2.165. 

Fig. 3.45. Chemical structure of azo dye Reactive yellow 84. Reprinted with permission from M. Koch et al. [120],...

The efficacy of diamond and metal-alloy electrodes for the degradation of the textile dyes Basic yellow 28 and Reactive black 5 was also followed by RP-HPLC. The chemical structures of the textile dyes under investigation are shown in Fig. 3.56. An ODS column (150 X 4.6 mm i.d. particle size 5 jttm) was employed for the RP-HPLC determination of... 

Thus, RP-HPLC-MS has been employed for the analysis of sulphonated dyes and intermediates. Dyes included in the investigation were Acid yellow 36, Acid blue 40, Acid violet 7, Direct yellow 28, Direct blue 106, Acid yellow 23, Direct green 28, Direct red 79, Direct blue 78 and some metal complex dyes such as Acid orange 142, Acid red 357, Acid Violet 90, Acid yellow 194 and Acid brown 355. RP-HPLC was realized in an ODS column (150 X 3 mm i.d. particle size 7 /.an). The composition of the mobile phase varied according to the chemical structure of the analytes to be separated. For the majority of cases the mobile phase consisted of methanol-5 mM aqueous ammonium acetate (10 90, v/v). Subsituted anthraquinones were separated in similar mobile phases containing 40 per cent methanol. The flow rate was 1 ml/min for UV and 0.6 ml/min for MS detection, respectively. The chemical structure of dye intermediates investigated in this study and their retention times are compiled in Table 3.28. It was found that the method is suitable for the separation of decomposition products and intermediates of dyes but the separation of the original dye molecules was not adequate in this RP-HPLC system [162],... 

The beneficial effect of the change of the flow rate of the mobile phase has also been exploited for the improvement of CCC purification of the components of the dye Quinoline yellow (Colour Index No. 47005). The chemical structures of the components of Quinoline yellow are shown in Fig. 3.121. The two-phase system used for the purification consisted of tm-butyl methyl ether-l-butanol-ACN-0.1 M TFA (1 3 1 5 v/v). The column... 

Ethoxylation of alkyl amine ethoxylates is an economical route to obtain the variety of properties required by numerous and sometimes small-volume industrial uses of cationic surfactants. Commercial amine ethoxylates shown in Tables 27 and 28 are derived from linear alkyl amines, aliphatic /-alkyl amines, and rosin (dehydroabietyl) amines. Despite the variety of chemical structures, the amine ethoxylates tend to have similar properties. In general, they are yellow or amber liquids or yellowish low melting solids. Specific gravity at room temperature ranges from 0.9 to 1.15, and they are soluble in acidic media. Higher ethoxylation promotes solubility in neutral and alkaline media. The lower ethoxylates form insoluble salts with fatty acids and other anionic surfactants. Salts of higher ethoxylates are soluble, however. Oil solubility decreases with increasing ethylene oxide content but many ethoxylates with a fairly even hydrophilic—hydrophobic balance show appreciable oil solubility and are used as solutes in the oil phase. 

Fig. 4 Chemical structures of triarylmethane (food green S and brilliant blue FCF), xanthene (erythrosine), and quinoline (quinoline yellow) dyes.

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