Indian Journal of Textile ResearchVol. 10, December 1985, Pp. 179-182

Azodisperse Dyes with Photochromic Mercury(II)-DithizonateMoiety for Dyeing Polyester, Nylon and Cellulose Triacetate Fibres

PH SHAH, (Miss) R G PATEL and V S PATEL

Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar 388120, India

Received 2 April 1985; revised and accepted 10 June 1985

Some 4-{arylazophenyI)mercury(II)dithizonates were synthesized and their dyeing performance on polyester, nylon andcellulose triacetate fibres was assessed. All the dye samples showed moderate to good fastness to light, and very good toexcellent fastness to washing, rubbing, perspiration and sublimation. The dyed fibres on exposure to bright sunlight or a lightsource of suitable wavelength showed a very good photochromic effect giving various shades. When the fibres were removedfrom sunlight the colour returned to the original shade. The duration required for this return depended on the intensity ofincident light, ambient temperature and the moisture content of fabric. Polyester fibres required a longer duration for attainingthe original shade but rapid change was observed by ironing the cloth. The return rate could be increased by keeping nylon

fibres in an oven at 80°C for 2-3 min and polyester fibres at 100°C for 2-3 m~

Keywords: 4-{ArylazophenyI)mercury(II)dithizonates, Azodisperse dyes, Cellulose triacetate dyeing, Nylon dyeing, Polyesterdyeing

Dithizone(diphenylthiocarbazone) has long been usedas a reagent for colorimetric analysis of trace ofmetals 1. Meriwether et ai.2 prepared 24 metalcomplexes of dithizone, characterized them andexamined their photochemical and photochromicbehaviour in --solution. Of these, the following ninecomplexes were photochromic under steady illumi­nation and with visible light: Pd(HDzh, Pt{HDz)2'AgHDz, Zn(HDzh, Cd(HDz)z, Hg(HDzh, Pb(HDz)z,Bi(HDzh, and Bi(HDzh Cl.2HCl. When the solutionsof metal-dithizonates in benzene or chloroform wereirradiated or placed in bright sunlight, they changedfrom their normal orange yellow colour to an intenseroyal blue. These workers found that the orange yellowcolour returned in dark, and the experiments could berepeated many times. The photochemical stability ofcomplexes in benzene solution to ultraviolet lightdecreased in the order Ni(HDzh > Zn(HDz)2> Hg(HDz)2 > Pd(HDz)2 > Pt(HDz)2 > AgHDz>Pb(HDzh > H2Dz > Cd(HDz}z.

Foster and Kazan3•4 synthesized photochromicmercury(I1)-dithizonate dye containing fibre-reactivedichloro-s-triazinyl group and applied this compoundas reactive dye on nylon. This yielded dyeing whichranged from orange through grey to blue dependingupon the intensity of incident light, ambienttemperature and the moisture content of fabric.However, no details of the dyeing properties of thecompound are reported. Also, no such dyes arereported as disperse dyes for polyester, nylon andcellulose triacetate fibres. Hence it was consideredworthwhile to prepare photochromic azo dyes

containing mercury(I1)-dithizonate moiety for dyeingthese fibres.

In this investigation, a number of dyes wereprepared by diazotizing p-aminophenylmercuricacetate, coupling with various coupling componentsand finally, condensing with dithizone. The dyeingperformance on polyester, nylon and cellulosetriacetate fibres was assessed.

The general scheme is as follows:

rO diozotisatlon -©-NH2 \ /. HgOC0CH3 ~ R - N ~N \ / HgOCOCHocoupling ;}

1dithizonePhI

N=N", ~I ./ Hg -B-N=N-RPhHNN~S

4-(Arylazophen)'I)mercur)'(II)dithizonate

where R is any of the coupling components listed inTable 1.

Materials and Methods

All the chemicals used were of A.R. grade.Phenylhydrazone and aniline were purified bydistillation.

p-Aminophenyimercuric acetate-The title com­pound was prepared by the method described inliteratures.

Diphenylthiocarbazone (Dithizone)- The title com­pound was prepared by the method described inliterature6.

179

INDIAN J. TEXT. RES., VOL. 10, DECEMBER 1985

n.ble 1-Yield, Melting Point, Molecular Formula, Elemental Analysis and Percentage Exhaustion of4-(Arylazophenyl) mercury(II)-di thizonate Dyes

Dye Coupling component of AmaxYieldm.p.Mol. formula Found (Calc.)Exhaustion, %No.

dye, R (log 6)°C(Mol. wt)C

HNHgPNCTA

Phenol

48080155 (d) CzsHzoON6HgS45.82.812.529.9453253

(4.3410)(652)(46.0)(3.0)(12.9)(30.7)

2p-Naphthol 47582180 (d) Cz9HnON6HgS49.02.811.528.0536760

(4.4457)(702)(49.5)(3.1)(11.9)(28.4)

3Resorcinol 48276170 (d) CzsHzoOzN6HgS44.52.7 _12.329.4333140

(4.2864)(668)(44.9)(2.9)(12.5)(29.9)

4p-Oresol ,470

84187 (d) Cz6HnON6HgS46.53.112.525.5593748

(4.3965)(666)(46.8)(3.3)(12.6)(30.0)

5Salicylaldehyde 48080175 (d) CZ6HzoOzN6HgS45.72.811.928.5513251

(4.2773)(680)

(45.8)(2.9)(12.3)(29.4)6

1,5-Dihydroxynaphtha1ene48579203 (d) C29Hn02N6HgS47.92.811.227.5453448

(4.3965)(718)(48.4)(3.0)(11.6)(27.8)

72,7-Dihydroxynaphthalene48581145 (d) C29Hn02N6HgS48.02.711.527.4496751

(4.2864)(718)(48.4)(3.0)(11.7)(27.8)

81-~henyl-3-methyl-5- 46081180 (d) CZ9H240NsHgS47.22.915.026.8545850

pyrazolone(4.2135)(732)(47.5)(3.2)(15.3)(27.3)

9I~m-Chloropheny1)-3- 48582190 (d) CZ9Hz30NsHgSCI44.92.914.325.8565865

methyl-5-pyrazolone(4.2187)(766)(45.4)(3.0)(14.6)(26.1)

104-Methyl-7-hydroxy- 47084175 (d) C29Hn03N6HgS47.32.611.026.7401841

coumarine(4.1568)(734)(47.4)(2.9)(11.4)(27.2)

118-Hydroxyquinoline 48582185 (d) C2sH210N7HgS47.22.510.819.3755450

(4.4608)(703)

(47.7)(2.7)(11.0)(19.8)

P-Polyester; N-Nylon; and CTA-Cellulose triacetate

4-(Arylazophenyl)mercury(/l) dyes-A well-stirredsoluti,on of mercurated amine, p­amino phenylmercuric acetate (0.1 mol) in 2 Nhydrochloric acid (125 ml) was cooled in an ice-saltbath and diazotized with 1N sodium nitrite solution(100 rril). The mixture was stirred and tested forcomplete diazotization using starch iodide paper. Ifthe mixture did not give the test, more sodium nitritesolution was added dropwise until a positive test wasobtained.

The hbove diazonium salt solution was added slowlyto a well-stirred solution of coupler (0.1 mol) in 8 gsodium hydroxide in water (40 ml) and the mixture wascooled, in an icebath. After the addition of diazoniumsolution, the reaction was tested for coupling. A dropof the reaction mixture was placed on a filter paper andthe colourless ring surrounding the spot dye wastreated with a drop of an alkaline solution of a reactivecoupler, l-amino-8-hydroxynaphthalene 3,6-disul­phonic acid. The presence of unreacted coupler couldbe determined in a similar manner using diazoniumsolution to test the colour ring.

Aftbr the completion of the coupling reaction, thereaction mixture was stirred for 15min and the dye wasprecipitated by adding dil. acetic acid. The crudeproduct was filtered, washed, dried and crystallizedfrom dil. acetic acid 7• The purity of product was tested

180

by using DMF-chloroform (2:5)system using silica gelas adsorbent.

4-(A rylazophenyl)mercury(I I)di thizona tes­Arylazophenyl mercuric acetate (above disperse dye)(0.0142 mol), dithizone (0.013 mol) and sodiumcarbonate (0.045 mol) were added to a vigorouslystirred mixture of water (100 ml) and chloroform (100mI). The colour of the mixture changed from purple toorange. After stirring for 30 min, chloroform wasevaporated under reduced pressure. The solid productwas filtered. The crude product was purified bycolumn chromatography using aluminium oxide andchloroform as solvent. The purity of the product wastested by TLC using ethylacetate-benzene (1:4)system,and silica gel as adsorbent.

Dyeing of polyester, nylon and cellulose triacetatefibres-The polyester and nylon fibres were treated atpH 5-6 (adjusted with acetic acid) for 15 min at 60°C.

The dyebath was prepared by dispersing the dye in adispersing agent (Dadamol) and a wetting agent(Tween 80).

The polyester fibres were dyed under pressure (H Tdyeing) at 120°C for 1 hr, the material-to-liquor ratiobeing kept at 1:50. The fibres were rinsed with coldwater and washed for 15min with a hot solution (95°C)containing soda ash (2 g/Iitre) and soap (1 g/Iitre). Thesuperficially adhering dye was completely removed

')

- - -.- -.--.----------------,

SHAH et at.: AZODISPERSE DYES FOR POLYESTER, NYLON & CELLULOSE TRIACETATE FIBRES

and the fibres were rinsed with cold water and air­dried.

Nylon and cellulose triacetate fibres were dyed at100°C for 90 min. The fibres were rinsed with cold

water and washed for IS min with a hot solution (9S0C)

containing soda ash (2 g/litre) and soap (I g/litre). Thesuperficially adhering dye was completely removedand fibres were rinsed with cold water and air-dried.

Fastness tests-Fastnesses to light, sublimation,

and acid and alkaline perspiration were assessed inaccordance with BS: 1006-1978. The rubbing fastnesstest was carried out by using a crockmeter (Atlas) inaccordance with AA TCC-1961, and the wash-fastnesstest, in accordance with IS: 76S-1979.

Al easurement of return rate-The return rates for allthe three dyed fibres were assessed by exposing thefibres in bright sunlight for 2-S min and then keeping inan oven maintained at 80°C for nylon and 100°C forcellulose triacetate and polyester fibres. The rate wasalso measured at room temperature.

Results and Discussion

Data on yield, melting point, elemental analysis andpercentage exhaustion of the dyes prepared are givenin Table I. All the melting points are uncorrected.

The rate of exhaustion of the dye bath was assessed

by varying the concentration of dye and pH of thedye bath, the temperature being kept constant.Maximum exhaustion of the dyebath took place atabout 2% concentration of the dye and pH 4.

The percentage exhaustion on nylon and cellulosetriacetate was good for dyes obtained from coupling

the p-aminophenylmercuric acetate with P-naphthol,2,7-dihydroxynaphthalene, I-phenyl-3-methyl-S­pyrazolone, 1-(m-chlorophenyl)-3­methyl-S-pyrazolone, and 8-hydroxyquino­line, while dyes obtained from phenol, resorcinol, p­cresol, I,S-dihydroxynaphthalene, and 7-hydroxy-4­methylcoumarine showed poor to moderate exhaus­

tion. The percentage ex.haustion on polyester was verygood for dye obtained from 8-hydroxyquinoline, whiledyes obtained from the other coupling componentsshowed moderate t9 good exhaustion; dyes fromresorcinol and 7-hydroxy-4-methylcoumarine wereexceptions. Among these dyes, those containinghydroxy groups in the ortho position of the azo groupshowed better exhaustion than those that contained

hydroxyl groups in para position. In the case of8-hydroxyquinoline dye, because of bonded hydroxygroup with heterocyclic nitrogen atom, the exhaustionwas high.

IR spectra-Infrared spectra were recorded on aPerkin Elmer 983 spectrophotometer in KBr. All thedyes showed bands at. noes) cm -1 (c - S stretching),1280(m), 1190(s), 1ISO(m) and 1120(s) cm -1(coupled N-C-S bond vibration), 1300(s)~nd 1320(m)cm -1 (N­

phenyl group), IS20(s) and 1490(s) cm -1 (C=N andNH groups), and 1600-1610(s) cm -1 (phenyl ring). Thedyes with coupling components phenol, P-naphtholand I,S-dihydroxynaphthalene showed a weak to

Table 2-Shades and Return Rates of 4..(ArylazophenyJ)mercury(II)-dithizonate Dyes on Polyester, Nylon and CelluloseTriacetate Fibres

Dye Colour of dyeingTime ofReturn rate, minNo.

irradiation, min

PNand CTA PNand CTA

PNand

BeforeAfterBeforeAfter CTA30°C 100°C 30°C 80°C

irradiation

irradiationirradiationirradiation

IOrange brownDark greyOrangeGrey25 2353.5

2Brilliant orangeBrownish orange OrangeBluish grey25. 2403.5

3Orange Wooden brownBrownish orange Wooden brown25 2405

4YelJowish orange Leafy green Light reddishBrown25..c:2403.5on

orange

:.a

;>,5 Orange Dark violetLight reddishBluish grey25Qj2303.5

green

orangeS

ll)•...

6Crimson Violet brownCrimsonViolet25>< 2303.5

7

Wooden brownDark greyBrownish orange Brown25UJ2453.5

8Yellow orangeMilitary greenOrangeGrey25 2455

9

Orange Wooden brownCreamGrey25 2355

iO

Light orangeKhakhi greenBrownish orange Brown25 3455

IIOrange BrownBrownish orange Brown25 2153

N-Nylon; P-Polyester; and CTA-Cellulose triacetate

181

INDIAN J. TEXT. RES., VOL. 10, DECEMBER 1985

Table 3-Fastness of Different 4-{ArylazophenyI)mercury(II)-dithizonate Dyes on Polyester, Nylon and Cellulose TriacetateFibres

DyeNo.

Light fastness Wash fastness Rubbing fastness Perspiration fastness Sublimationfastness

P N CTA P N CTA P N P N CTAPNCTA

Dry

WetDryWetAcid Alka- Acid Alka- Acid Alka-line

lineline

I3334445'5 55555555555

233-435445544555455555

3

3-43342-34-4444454455554

33-4344444555554545555

4334-53355445555555556

3-433-453355445555554547

33-4342-3355445444445448

4334-54455435555554449

333444554'4555555555

103334445554555555555

II3334445554555555555

P-Polyester; N-Nylon; and CTA-Cellulose triacetateI

medium stretching frequency at 3240-3250 cm -1 (NH

groups), while the free or bonded OH groupfrequencies were absent. Dyes with the couplingcomponent pyrazolone, quinoline and coumarineshowed a,strong and broad band at around 3250-3600cm -1 (bonded OH group with - N = N-group) alongwith a hump at 3240-3250 cm -1 (- NH groups).

Shade+- Table 2 shows that for nylon and cellulosetriacetate fibres the shade varied from orange tobrownis~ orange. On exposure to bright sunlight theorange shade changed from orange through grey tobluish grey; brownish orange changed to violet. Thereturn rate of the shade at room temperature variedfrom 30 to 45 min. For polyester fibres the shade variedfrom yellow-orange to brown. On exposure to brightsunlight" various shade changes were observedcompared to those in nylon and cellulose triacetate

fibres. Dyes containing the couqling component, p­cresol, s~licylaldehyde, pyrazol01e derivatives and 7­hydroxy'-4-methylcoumarine on polyester fibres

changed from orange to greenis~ shade. The returnrate of shade at room temperatur~ was extremely high

in the case of polyester compared Ito that in the case ofnylon and cellulose triacetate, while it varied from 2 to3 min at loooe

Ps2

Fastnessproperties-Data on the fastness properties(Table 3) show that the light fastness ranges from goodto fairly good for all the three fibres. The washing,

rubbing and perspiration fastnesses were very fair togood to excellent for all the three fibres. Sublimationfastness was good to excellent for all dyes on all thethree fibres.

AcknowledgementOne of the authors (PHS) expresses his appreciation

to the Council of Scientific & Industrial Research, New

Delhi, for the award of a senior research fellowship

during investigation.

References

I Sandell E B, in Colorimetric determination of traces of metals,edited by B L Clarke and I M Kolthoff (IntersciencePublishers Inc, New York) 1959, 100.

2 Meriwether L S, Breitner E C and Sloan L S, J Am chernSoc, 87(1965) 444l.

3 Foster W H (Jr) and Kazan J, Tex Res J, 37 (1967) 376.

4 Kazan J and Foster W H (Jr), US Pat 3,505,306 (to AmericanCyanamid Co.) 7 April 1970;Chern Ahstr, 73 (1970) 46684m.

5 Otto Dimroth Ueber die, Ber dt chern Ges, 35 (1902) 2032.

6 Billman J H and Cleland E S, Org Synth, 25 (1945) 38.7 Guha-Sircar S S and Rout M K, J IndialJchernSoc, 30 (1953) 363.