orange-II dye or 2-naphthol orange or β-NAPHTHOL ORANGE - mono-azo acidic dye, or basic orange-2 - study everything.

ORANGE-II [β-NAPHTHOL ORANGE OR 2-NAPHTHOL ORANGE]

WHAT IS DYES ? [5.1]

Definition : generally dye is a colored organic compound or mixture which used for imparting color to the substrate or objects like paper, plastic , cloths , and leather etc.

The  long time stability is required for good quality of dye.

The dyed substrate should be resistant to a normal cleaning procedures and stable to light.

ORANGE-II [β-NAPHTHOL ORANGE OR 2-NAPHTHOL ORANGE]

Orange-II dye is a mono-azo (-N=N-) acidic (here the acid is SO₃H) dye.

It is synthesized from sulphanilic acid.

CHEMICAL PROPORTIES :[ 5.2]

IUPAC NAME :   4-( 2-hydroxy-1-naphthylazo )benzene sodium sulphonate.

STRUCTURE FORMULA :

PHYSICAL PROPERTIES :[5.3]

MOLECULAR FORMULA : C₁₆H₁₁O₄N₂Na S

MOLECULAR WEIGHT : 350.32 gm/mole.

MALTING POINT : 164^OC.

BOILING POINT : sorry for inconvenience we will give update as possible as soon.

SOLUBILITY : very soluble in water ( 116 gm/l at 30^oc ).

                         Slightly soluble in ethanol and acid(hcl).

COLOR : orange.

STATE : crystalline powder.

ODOR : odorless.

SYNTHESIS OF ORANGE-II [5.4]

Synthesis of orange-ii from sulphanilic acid.

STATEMENT :  in the reaction first the sulphanilic acid dissolve in HCL & diazotized with NaNO₂ at 0-5^OC temperature, after that these reactant react with β-naphthol at that time the temperature of entire system is 8^oc, these reaction will take a two hours , then the temperature raised from 8 to 16^oc . at that time the p^H of solution is about 9.1 to 9.4.

P^H IS lowered by adding acidifying substance (HCL) , yields orange-ii dye , further filtration and the drying process gives main product ( pure ) orange-ii dye.

CHEMICAL REACTION :

USES OF ORANGE-II DYE : [5.5]

Orange-ii dye is used widely for dying many numbers of substrate given below.

(i)                  Cotton

(ii)                Wool

(iii)               Fibres

(iv)              Silk

(v)                Paper

(vi)              Leather

NOTE : some dyes are ( azo dyes )  toxic in nature it is require to take care when use these type of dyes.

GENERAL INFORMATION [5.6]

DIAZOTIZATION REACTION :

STATEMENT : diazotization is the reaction in which the primary aromatic amine converts into diazonium(N=N) salt.

In other words

The reaction of primary aromatic amine with NaNO₂ and HCL yields diazotized product.

GENERAL CHEMICAL REACTION :

Diazonium salt is shown by general formula as Ar-N₂⁺x^-

Where x = CL^-, Br ^-, HSO₄^- , BF₄^- , etc. Group is called diazonium group.

In their nomenclature the suffix diazonium is applied to main hydrocarbon and then the name of negative ion is written.

Primary aliphatic amine forms highly unstable alkyl diazonium salt,

While primary aromatic amine forms arene diazonium salt it is very stable compare to the aliphatic alkyl diazonium salt cause of resonance.

Example : diazotization of aniline.

STATEMENT :  the reaction of aniline with NaNO₂ and HCl,  HNO₂ is used as a catalyst , 273 – 278 k temperature yields benzene diazonium chloride (salt).

Benzene diazonium salt is very unstable at higher temperature , so it is necessary to keep the temperature at 273 – 278 k.

CHEMICAL REACTION : 

see also :

what is science ? all about science.  [click here].

 ATENOLOL [TENORMIN] - medicinal drug   [click here].

ADRENALINE [EPINEPHRINE]  - medicinal drug -hormone  [click here].

IBUPROFEN DRUG [NSAID'S] [click here]

crsodine - G  or (2,4-diamino-azobenzene) or mono-azo- basic dye  [click here].

auramine-o or yellow dye or diarylmethane dye or bis [4-(dimethyl amine ) phenyl ] – methanimium chloride. [click here]

michler's ketone[click here]

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