METHYL ORANGE ORANGE DYE FAST RED B MORDENT YELLOW CONGO RED METANIL YELLOW CRYSODINE ROSINDULINE BASIC YELLOW 11 BASIC YELLOW 21 PRUSSIAN BLUE ETC.. PROPERTIES AND APPLICATION

1. ch.1: Structures and
synthesis
By primal hirpara

2. Methyl orange

4. Orange dyes

5. Fast red B

6. MORDENT YELLOW

7. Congo Red
 It is an diazo dye, containing two azo groups.
 It is a direct dye for cotton.
 It is used as an indicator also( Blue in acidic solution and red in
alkaline solution)
 Congo red is used as an indicator in acid-base titration. Congo red
paper is used for testing acidity of the solution.
 Structure:
NH2
SO3Na
N N N N
NH2
SO3Na
Congo Red(Disodium salt)

8. Synthesis of Congo Red
• Congo red is synthesised by coupling between
tetrazotised benzidine and two molecules of
naphthionic acid.
• Step I : preparation of tetrazotised
benzidine
H2N NH2
NaNO2, HCl
o
0 -5 C
2
N Cl
ClN2
tetrazotised benzidine

9. Step II : Coupling of tetrazotised benzidine with
naphthionic acid
NH2
SO3Na
N N N N
NH2
SO3Na
tetrazotised benzidine
+ ClN2 N2Cl +
H
SO3Na
H H
NH2
SO3Na
-2HCl
Coupling
Congo Red
NaOH HCl
NH2
SO3Na
N N N N
NH2
SO3Na
Congo Red(disodium salt)

10. Metanil yellow
 Metanilic acid is diazotized and coupled with
diphenylamine gives metanil yellow.
 Since Diphenyl amine is insoluble in water, coupling
reaction has to be carried out by emulsifying
diphenylamine in water before coupling.
 Metanil Yellow is used for dyeing silk and cotton
fibers.

12. Chrysodine dye

13. Rosinduline
• The dye, Rosinduline 2 G (Colour Index No. 830, or Schultz’ Farbstofftabellen No. 674,
synthesized by Hepp in 1890).
• It is the sodium salt of a monosulfonic acid of the compound shown in the formula (called
Rosindon).
• Rosindulin is a dark red solid that is sparingly soluble in water.
• The free acid can be precipitated one of the benzene rings; it is unknown in which.
• The dye has an intense scarlet red color
• The dye is easily soluble and stable both in the oxidized and reduced state even in very
strongly alkaline solution and so differs, advantageously, from all dyes of a comparably
negative potential range
• The dye can be reduced by colloidal palladium and hydrogen; the leucodye is easily
soluble and very stable,
• Molecular Formula: C 28 H 18 N 3 NaO 6 S 2
• Molecular Weight: 579.59
• CAS No.: 25641-18-3
• In microscopy , biological preparations are stained with Azocarmin G. Histologically ,
Azocarmine G ( Az ) and Aniline Blue( An ) are used as Azan stains to distinguish between
cells and the surrounding matrix.

14. Rosinduline

15. Basic Yellow 11

16. Properties:
 Name:C.I.Basic Yellow 11,C.I.48055
 Molecular Structure: Methine class
 Molecular Formula:C21H25ClN2O2
 Molecular Weight: 372.89
 CAS Registry Number:4208-80-4
 Manufacturing Methods :2-(1,3,3-Trimethylindolin-2-
yl)acetaldehyde and 2,4-Dimethoxybenzenamine condensation.

17. Applications:
 brilliant yellow. Talk of green light yellow powder. In cold water micro dissolve, is
soluble in hot water, soluble in ethanol (solution for yellow).
 Used for the acrylic fabric dyeing, also used in vinegar fiber and PVC fiber color.

18. Basic Orange 21

19. Properties:
 Molecular Structure: Multi-methine class
 Name:C.I.Basic Orange 21,
 Molecular Formula:C22H23ClN2
 Molecular Weight: 350.88
 Manufacturing Methods : 2-(1,3,3-Trimethylindolin-2-yl)acetaldehyde and 2-Methyl-2H-
indazole in 90 ℃ in the condensation, and then dumped into the water, and translated into
chloride.
 Properties :bright yellow orange. Soluble in water and ethanol are yellow, slightly soluble in cold
water, soluble in hot water. Dye acrylic fiber as a bright yellow orange, tungsten filament in light
slant red light. In 120 ℃ dyeing color when unchanged. In the dying encounter copper, iron ion
colored light changes greatly.
 Applications:
This product used for acrylic, two vinegar fiber, modified polyester dyeing and printing.

20. Basic information
iupac name : 4-[[4-[(6-anilino-1-hydroxy-3-sulfonaphthalen-2-yl)diazenyl]-5-methoxy-
2-methylphenyl]diazenyl]-5-hydroxynaphthalene-2,7-disulfonic acid
 ;Direct Blue 81;Direct blue 81 (C.I. 34215);Blue 81;C.I.34215;C.I.Direct Blue
81
 M F: C46H27N7Na4O14S4
 M W: 1121.96
Sirius Supra Blue
Molecular Weight 793.8 g/mol

21. Safranin B
Solid safranin Safranin in aqueous solution

22. Basic Information:
 Safranines are the azonium compounds of symmetrical 2,8-dimethyl-3,7-diaminophenazine.
 They are obtained by the joint oxidation of one molecule of a para-diamine with two molecules of
a primary amine; by the condensation of para-aminoazo compounds with primary amines, and by
the action of para-nitrosodialkylanilines with secondary bases such as
diphenylmetaphenylenediamine.
 They are crystalline solids showing a characteristic green metallic lustre; they are readily soluble in
water and dye blue or violet. They are strong bases and form stable monacid salts.
 Their alcoholic solution shows a yellow-red fluorescence.
 Phenosafranine is not very stable in the free state; its chloride forms green plates.
 It can be readily diazotized, and the diazonium salt when boiled with alcohol yields aposafranine
or benzene induline, C18H12N3.

23. Basic Information:
 Molecular Structure: Symmetrical
2,8-dimethyl-3,7-diaminophenazine
 Name: Safranin
 Molecular Formula: C20H19ClN4
 Molecular Weight: 350.85
 CAS Registry Number:477-73-6
 Solubility in Water: Soluble

24. Prussian blue

25. Introduction
 Prussian blue is a dark blue pigment with the idealized chemical formula Fe7(CN)18.
 This complex compound the formula can also be written as Fe4[Fe(CN)6]3 · xH2O.
 Another name for the color is Berlin blue or, in painting, Parisian or Paris blue. Turnbull's
blue is the same substance, but is made from different reagents, and its slightly different
color stems from different impurities.
 Prussian blue was the first modern synthetic pigment. It is employed as a very
fine colloidal dispersion, as the compound itself is not soluble in water. It is famously
complex,[
 Owing to the presence of variable amounts of other ions and the sensitive dependence of
its appearance on the size of the colloidal particles formed when it is made.
 The pigment is used in paints, and it is the traditional "blue" in blueprints

26.  Because it is easily made, cheap, nontoxic, and intensely colored, Prussian blue has
attracted many applications.
 It was adopted as a pigment very soon after its invention and was almost immediately
widely used in oil, watercolor, and dyeing.
 The dominant uses are for pigments: about 12,000 tonnes of Prussian blue are produced
annually for use in black and bluish inks. A variety of other pigments also contain the
material.
 Engineer's blue and the pigment formed on cyanotypes—giving them their common name
blueprints. Certain crayons were once colored with Prussian blue (later relabeled midnight
blue).
 It is also a popular pigment in paints. Similarly, Prussian blue is the basis for laundry bluing.

27. Properties
 Prussian blue is a microcrystalline blue powder. It is insoluble, but the crystallites
tend to form a colloid. Such colloids can pass through fine filters.
 Despite being one of the oldest known synthetic compounds, the composition of
Prussian blue remained uncertain for many years. Its precise identification was
complicated by three factors:
 Prussian blue is extremely insoluble, but also tends to form colloids.
 Traditional syntheses tend to afford impure compositions.
 Even pure Prussian blue is structurally complex, defying routine crystallographic
analysis.

28. Crystal structure
 The chemical formula of insoluble Prussian blue is Fe7(CN)18 · xH2O, where x = 14–16.
 The structure was determined by using IR spectroscopy, Mössbauer spectroscopy, X-ray
crystallography, and neutron crystallography. Since X-ray diffraction cannot distinguish
carbon from nitrogen, the location of these lighter elements is deduced by spectroscopic
means, as well as by observing the distances from the iron atom centers.
 PB has a cubic lattice structure. Soluble PB crystals contain interstitial K+ ions; insoluble PB
has interstitial water, instead.
 In ideal insoluble PB crystals, the cubic framework is built from Fe(II)–C–N–Fe(III)
sequences, with Fe(II)–carbon distances of 1.92 Å and Fe(III)–nitrogen distances of 2.03 Å.
 One-fourth of the sites of Fe(CN)6 subunits are vacant (empty), leaving three such groups.
The empty nitrogen sites are filled with water molecules, instead, which are coordinated to
Fe(III).

29.  The Fe(II) centers, which are low spin, are surrounded by six carbon ligands in an
octahedral configuration.
 The Fe(III) centers, which are high spin, are octahedrally surrounded on average by 4.5
nitrogen atoms and 1.5 oxygen atoms (the oxygen from the six coordinated water
molecules).
 Additional eight (interstitial) water molecules are present in the unit cell, either as
isolated molecules or hydrogen bonded to the coordinated water.
 The composition is notoriously variable due to the presence of lattice defects, allowing it
to be hydrated to various degrees as water molecules are incorporated into the structure
to occupy cation vacancies.
 The variability of Prussian blue's composition is attributable to its low solubility, which
leads to its rapid precipitation without the time to achieve full equilibrium between solid
and liquid

30.  Color
 Prussian blue is strongly colored and tends towards black and dark blue when mixed into oil paints.
The exact hue depends on the method of preparation, which dictates the particle size.
 The intense blue color of Prussian blue is associated with the energy of the transfer of electrons
from Fe(II) to Fe(III). Many such mixed-valence compounds absorb certain wavelengths of visible
light resulting from intervalence charge transfer.
 In this case, orange-red light around 680 nanometers in wavelength is absorbed, and the reflected
light appears blue as a result.
 Like most high chroma pigments, Prussian blue cannot be accurately displayed on a computer
display. PB is electrochromic—changing from blue to colorless upon reduction.
 This change is caused by reduction of the Fe(III) to Fe(II) eliminating the intervalence charge
transfer that causes Prussian blue's color.

31.  Synthesis
 Necessary materials
 Laboratory tools: 1 beaker, 2 test tubes, 1 crucible, 1 asbestos sieve with tripod, 1 filter,
1 filtrating installation
 Chemical substances: K4[Fe(CN)6] crystals, FeCl3 solution (or any other Fe(III)
solution)
 Method of working
 Prepare 200 ml of FeCl3 in the beaker. FeCl3 has a reddish-yellow colour and looks like
this:

32.  Then prepare two K4[Fe(CN)6] solution by dissolving 10 mg of potassium
Ferro cyanide into 20 ml water in each test tube. Put enough FeCl3 for the
precipitate to appear in both test tubes. The change of color is immediate:
 The chemical equation on which the reaction is based is:
 4 FeCl3 + 3 K4[Fe(CN)6] -> Fe4[Fe(CN)6] + 12 KCl

34.  Prepare the filtering installation and then put the solution from the
second test tube on the beaker.

35.  As you see, Prussian blue is perfectly insoluble in water, the only thing that is
filtered being the FeCl3 solution that was used a bit too much:

37. Thank you