A new kind of H-acid monoazo-anthraquinone reactive dyes with surprising colour

Article abstract of DOI:10.1016/j.dyepig.2015.07.001

A new kind of reactive dyes containing both monoazo and anthraquinone chromophores was obtained by using 1,4-bis((4-aminophenyl)amino)anthrancene- 9,10-dione as diazo component and 1-amino-8-naphthol-3,6-disulfonicacid (H-acid) derivatives as coupling components. The dyes were characterized by UV-Vis, IR, MS, ¹H NMR and ¹³C NMR. The results showed that the maximum absorption wavelengths of the dyes were all about 590 nm, which indicated that they were a kind of blue dyes. ¹H NMR and ¹³C NMR results revealed that there were two kinds of tautomerisms in dye structure and a new conjugated system formed between the anthraquinone ring and the phenyl azo linkage. Density functional theory (DFT) calculations also proved the formation of the new larger conjugated system from which the blue colour was generated. The fixations of the dyes on cotton were over 88% and the light fastness reached 5 grade.

Full text of DOI:10.1016/j.dyepig.2015.07.001

Accepted Manuscript
A new kind of H-acid monoazo-anthraquinone reactive dyes with surprising colour
Bin Shan, Xing Tong, Wei Xiong, Wenzhu Qiu, Bingtao Tang, Rongwen Lu, Wei Ma,
Yi Luo, Shufen Zhang
PII:
S0143-7208(15)00255-7
10.1016/j.dyepig.2015.07.001
DYPI 4839
DOI:
Reference:
To appear in: Dyes and Pigments
Received Date: 1 March 2015
Revised Date: 27 June 2015
Accepted Date: 1 July 2015
Please cite this article as: Shan B, Tong X, Xiong W, Qiu W, Tang B, Lu R, Ma W, Luo Y, Zhang S, A
new kind of H-acid monoazo-anthraquinone reactive dyes with surprising colour, Dyes and Pigments
(2015), doi: 10.1016/j.dyepig.2015.07.001.
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to
our customers we are providing this early version of the manuscript. The manuscript will undergo
copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please
note that during the production process errors may be discovered which could affect the content, and all
legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
A new kind of H-acid monoazo-anthraquinone reactive dyes
with surprising colour
Bin Shan, Xing Tong, Wei Xiong, Wenzhu Qiu, Bingtao Tang, Rongwen Lu, Wei Ma,
Yi Luo, Shufen Zhang
State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012, PR China
Abstract
A new kind of reactive dyes containing both monoazo and anthraquinone
chromophores was obtained by using 1,4-bis((4-aminophenyl)amino)anthrancene-
9,10-dione as diazo component and 1-amino-8-naphthol-3,6-disulfonicacid (H-acid)
derivatives as coupling components. The dyes were characterized by UV-vis, IR, MS,
1H NMR and 13C NMR. The results showed that the maximum absorption
wavelengths of the dyes were all about 590 nm, which indicated that they were a kind
1
of blue dyes. H NMR and 13C NMR results revealed that there were two kinds of
tautomerisms in dye structure and a new conjugated system formed between the
anthraquinone ring and the phenyl azo linkage. Density functional theory (DFT)
calculations also proved the formation of the new larger conjugated system from
which the blue colour was generated. The fixations of the dyes on cotton were over 88%
and the light fastness reached 5 grade.
Key words: Monoazo-anthraquinone structure; Reactive dye; Blue colour;
Tautomerism; DFT calculation; Dyeing properties.
1 Introduction
Corresponding author. Tel.: +86 411 84986265; fax: +86 411 84986264.
E-mail address: zhangshf@dlut.edu.cn
1

ACCEPTED MANUSCRIPT
Reactive dyes are the most important class of dyes since they can be linked onto the
textile fibres through covalent bonds and the coloured fibres have high fastness to wet
treatment [1−2]. In reactive dyes, azo dyes and anthraquinone dyes are two of the
most important kinds of dyes. Among them, azo dyes contribute greatest production
volume of the dyestuff industry due to cheap raw materials, simple mode of synthesis,
and high molar absorption coefficient. Unfortunately, the azo groups in the dye
chromophore usually result in the dye having poor light stability [3−5]. In contrast,
anthraquinone dyes, surpassed in importance only by azo dyes, have excellent light
fastness properties [6−7]. However, the relatively low molar absorption coefficient is
the significant deficiency of the anthraquinone dyes [8−9].
There have been some reports about the incorporation of anthraquinone structure
into the azo dyes to get azo-anthraquinone dyes with high light stability and tinctorial
strength. Klaus Korte, et al. [10] invented a kind of green water-soluble
azo-anthraquinone acid dyes derived from 1-amino-4-bromoanthraquinone-2-sulfonic
acid derivatives. BaettigKurt, et al. [11] and Jae Bok Chang, et al. [12] respectively
developed a species of water soluble azo-anthraquinone acid dyes for ink jet printing
and dichroic dyes for PVA polarizing films with red colour shades, synthesized by
using 1,5-diaminoanthraquinone or 2,6-diaminoanthraquinone as diazo component
and 1-amino-8-naphthol-4,6-disulfonic acid or 2-amino-5-naphthol-7-sulfonic acid as
coupling component. Zhibin Cai, et al. [13] reported six yellow azo-anthraquinone
disperse dyes, obtained from 1,5-bis(phenyl azo)-9,10-anthracenedione or
2,6-bis(phenyl azo)-9,10-anthracenedione compounds. All these azo-anthraquinone
2

ACCEPTED MANUSCRIPT
dyes possess high light stability and their colours range from yellow to red and
assorted green.
As mentioned above, the chromophore comtainning one anthraquinone and two azo
structures could have the high molar absorption coefficient and light fastness. And
compared with 1,5 and 2,6-disubstituted anthraquinone derivatives, 1,4-disubstituted
anthraquinone derivatives with lower energy gap between HOMO and LUMO of the
molecular systems are more prone to get deep colour shades [14-15]. Therefore, in
this work, the 1,4-disubstituted anthraquinone structure was incorporated into the azo
dyes to synthesize a new kind of reactive dyes with deep colour shade. The dyes were
prepared by using 1,4-bis((4-aminophenyl)amino) anthrancene-9,10-dione as diazo
component and H-acid derivatives as coupling components. It was surprising that the
colours of these dyes were blue, which were completely different from those of
traditional H-acid monoazo dyes. In this study, the relationship between the new
monoazo-anthraquinone dyes and spectral properties was discussed and the dyeing
properties were examined as well as their fastness.
2 Experimental
2.1 Materials and instruments
Cyanuric
chlorine,
1-amino-8-naphthol-3,6-disulfonicacid
acid, 3-aminobenzenesulfonic
(H-acid),
acid,
2-aminobenzenesulfonic
2-((4-aminophenyl)sulfonyl)ethyl hydrogen sulfate, 2-aminobenzene-1,4-disulfonic
acid and C.I. Reactive Red 253 were obtained from Zhejiang Shunlong Chemical Co..
1,4-Dihydroxyanthraquinone was purchased from Yichun Industries Co. and
3

ACCEPTED MANUSCRIPT
N-(4-aminophenyl)acetamide was purchased from Aladdin Chemistry Co. Ltd..
Aniline and 4-aminobenzenesulfonic acid were purchased from Tianjin Damao
Chemical Reagent Co. and 4-aminobenzoic acid was purchased from Tianjin Guangfu
Chemical Reagent Co.. All other chemicals used in this study were of synthetic grade.
NMR spectra were recorded on a spectrometer INOVA 500 (Varian, USA) using
DMSO-d6 as the solvent and TMS as the internal standard, respectively. FT-IR
spectra were recorded on a JASCO 430 spectrometer (JASCO, Japan) using KBr
pellets. API-ES-Mass spectra were carried out on HP1100 mass spectrometer
(Hewlett-Packard, USA). UV-vis spectra were recorded using a spectrometer
HP-8453 UV-visible (Hewlett-Packard, USA). Cotton dyeing was operated using
1002 (Roaches Co., UK) Padding, Drying, Heat-setting and Steam Combination
Apparatus.
2.2 Synthesis of dyes
2.2.1 Synthesis of 1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione (3)
Compound 3 was synthesized from 1,4-dihydroxyanthraquinone by the route
depicted in Scheme 1.
A mixture of 2.48 g 1,4-dihydroxyanthraquinone (0.01 mol, 97%), 2.33 g sodium
carbonate (0.022 mol) and 50 mL water was heated at 85 oC under nitrogen protection
and then 4.26 g (0.022 mol, 90%) of sodium hydrosulfite was added. Thin layer
chromatography (TLC) was used to monitor the completion of the reaction (mobile
phase: PhMe:EtOAc, 14:3, v/v, Rf =0.81). After stirring for 2 h, the reaction mixture
was filtrated and washed with 2×500 mL of hot water (40−50 oC). The brown powder
4

ACCEPTED MANUSCRIPT
was dried in vacuum and 1,4-dihydroxyanthraquinone Leuco product was obtained
(Yield: 96.1%).
A solution of 2.44 g 1,4-dihydroxyanthraquinone Leuco (0.01 mol), 3.3 g
N-(4-aminophenyl)acetamide (0.022 mol) and 1.2 g boric acid (0.02 mol ) in 100 mL
xylene was heated at 136 oC to reflux for 24 h under nitrogen protection. Meanwhile,
TLC was used to monitor the completion of the reaction (PhMe:EtOAc, 14:3, v/v, Rf
o
=0.22). When the reaction was completed, the mixture was cooled to 70 C and
oxidized by the blowing air. After stirring for 3 h, the solvent was evaporated under
the reduced pressure. Then hot water was added to wash the resulting solid, and the
mixture
was
filtered
to
give
N,N'-(((9,10-dioxo-9,10-
dihydroanthracene-1,4-diyl)bis(azanediyl))-bis(4,1-phenylene))diacetamide product
(Yield: 88.3%).
Concentrated HCl (0.1 mol) was added to
a
stirred solution of
N,N'-(((9,10-dioxo-9,10-dihydroanthracene-1,4-diyl)bis(azanediyl))bis(4,1-phenylene
))diacetamide (5.04 g, 0.01 mol) in ethylene glycol (50 mL). The reaction mixture was
heated to reflux and the reaction was monitored by TLC (PE:EtOAc, 1:3, v/v, Rf
=0.42). When the reaction was completed, the solvent was evaporated under the
reduced pressure and the residue was purified by washing with ethylene glycol
monomethyl ether to achieve 3.85 g compound 3 (Yield: 91.7%).
IR (KBr, cm-1): 3420 (N–H), 3039 (Ar–H), 1614 (C=O), 1595, 1513 (C=C), 1569
1
(N–H), 1259 (C–N). H NMR (DMSO-d6): δ 12.3 (s, 2H, Ar–NH), 6.6–8.2 (m, 14H,
Ar–H), 5.2 (s, 4H, Ar–NH2). 13C NMR (DMSO-d6): δ 180.7 (C=O), 146.8 (=C–NH2),
5

ACCEPTED MANUSCRIPT
145.0 (=C–NH), 133.7 (Ar–C), 132.4 (Ar–CH), 126.5 (Ar–CH), 125.7 (Ar–CH),
125.4 (Ar–CH), 114.5 (Ar–C) . MS (API-ES): m/z= 420.16, found 421.1, [M+H]+.
2.2.2 Synthesis of H-acid monoazo-anthraquinone reactive dyes
A series of dyes were synthesized by the route depicted in Scheme 2. The dyes
7a–g listed in Table 1 were prepared as described below.
Diazotization reaction of 1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione:
1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione (2.40 g, 0.005 mol) was
dissolved in hydrochloric acid (37%, 2.5 mL, 0.015 mol). The mixture was cooled in
an ice-water bath and then 0.0105 mol of NaNO2 was added into the solution. The
reaction mixture was stirred for 30 min until no chromogenic reaction to the Erich
reagent was detectable. Excess nitrous acid was decomposed by sulfamic acid to give
the solution of the diazo salt.
Condensation reaction of cyanuric chloride: Cyanuric chloride (1.90 g, 0.0103 mol)
was introduced into 20 g of ice cubes with 2 mL of water and the mixture was stirred
at a temperature of 0–5 °C. After stirring for 30 min, 4a–g (0.01 mol) was added. The
temperature of the mixture was maintained at 0–5 °C and pH was maintained at 4–5
using 10% Na2CO3 aqueous solution. The reaction mixture was stirred for about 1 h
until no chromogenic reaction to the Erich reagent was detectable. And then 4.0 g
(0.01 mol, 85.6%) H-acid was added and the reaction was performed at 25–30 °C and
pH 5–5.5 using 10% Na2CO3 aqueous solution. The reaction mixture was stirred for
about 3–4 h to give the solution of 6a–g product and TLC was used to monitor the
completion of the reaction (n-PrOH:i-BuOH:EtOAc:H2O, 2:4:1:3, v/v).
6

ACCEPTED MANUSCRIPT
Coupling reaction: The solution of diazo salt made above was added slowly to the
solution of 6a–g product at pH 6–7. The mixture was stirred for 24 h at room
temperature and at pH 7–8 by adding 10% Na2CO3 aqueous solution.
4-acetamido-5-hydroxynaphthalene-2,7-disulfonic acid (Acetyl H-acid) and
4-nitroaniline diazonium salt were used to monitor the completion of the coupling
reaction. After addition of potassium acetate(15% w/v), the solid blue product was
isolated, collected by filtration, washed with ethanol for three times and dried in
vacuum. The H-acid monoazo-anthraquinone reactive dyes 7a–g were prepared in a
similar procedure and the unrefined products were purified by paper chromatographic
separation method (n-PrOH:i-BuOH:EtOAc:H2O, 2:4:1:6, v/v).
7a: Yield: 53.2%, Rf =0.70. IR (KBr, cm-1): 3417 (N–H and O–H), 1568 (N=N),
1485 (triazine), 1295 (C–N), 1195 (C–O), 1165, 1041 (–SO3H). 1H NMR (DMSO-d6):
δ 15.8 (s, 2H, N–H in hydrazone), 12.7 (s, 2H, Ar–NH), 12.3 (s, 2H, Ar–NH), 10.5 (s,
2H, Ar–NH), 8.8 (s, 4H, Ar–OH), 8.3–7.2 (28H, Ar–H). 13C NMR (DMSO-d6): δ
183.3(C=O), 174.2(C=O), 168.6(C–Cl), 165.0, 142.9 (C–N), 164.2, 129.2 (C=N),
152.1, 143.7, 139.4 (C–S), 111.9–138.8 (Ar–C). MS (API-ES): m/z=1648.04, found
823.1 ([M–2H]2-/2, 549.0 ([M–3H]3-/3), 411.1 ([M–4H]4-/4).
7b: Yield: 42.7%, Rf =0.68. IR (KBr, cm-1): 3418 (N–H and O–H), 1565 (N=N),
1489 (triazine), 1295 (C–N), 1211 (C–O), 1168, 1043 (–SO3H). 1H NMR (DMSO-d6):
δ 15.7 (s, 2H, N–H in hydrazone), 12.9 (s, 2H, Ar–NH), 12.3 (s, 2H, Ar–NH), 10.6 (s,
13
2H,Ar–NH), 8.9 (s, 4H, Ar–OH), 8.3–6.9 (28H, Ar–H). C NMR (DMSO-d6): δ
182.6 (C=O), 178.6 (C=O), 168.0 (C–Cl), 163.8, 142.5 (C–N), 163.4, 129.6 (C=N),
7

ACCEPTED MANUSCRIPT
152.0, 143.8, 138.9 (C–S), 111.5–137.6 (Ar–C). MS (API-ES): m/z=1648.04, found
823.1 ([M–2H]2-/2), 549.0 ([M–3H]3-/3), 411.1 ([M–4H]4-/4).
7c: Yield: 54.6%, Rf =0.69. IR (KBr, cm-1): 3414 (N–H and O–H), 1567 (N=N),
1508 (triazine), 1295 (C–N), 1216 (C–O), 1165, 1045 (–SO3H). 1H NMR (DMSO-d6):
δ 15.8 (s, 2H, N–H in hydrazone), 12.6 (s, 2H, Ar–NH), 12.3 (s, 2H, Ar–NH), 10.5 (s,
2H, Ar–NH), 8.9 (s, 4H, Ar–OH), 8.3–7.2 (28H, Ar–H). 13C NMR (DMSO-d6): δ
183.0 (C=O), 179.2 (C=O), 172.5 (C–Cl), 164.3, 142.9 (C–N), 163.8, 130.2 (C=N),
153.4, 143.9, 139.3 (C–S), 111.7–138.0 (Ar–C). MS (API-ES): m/z=1648.04, found
823.1 ([M–2H]2-/2), 549.0 ([M–3H]3-/3), 411.1 ([M–4H]4-/4).
7d: Yield: 56.5%, Rf =0.64. IR (KBr, cm-1): 3405 (N–H and O–H), 1568 (N=N),
1486 (triazine), 1294 (C–N), 1214 (C–O), 1165, 1043 (–SO3H). 1H NMR (DMSO-d6):
δ 15.8 (s, 2H, N–H in hydrazone), 12.8 (s, 2H, Ar–NH), 12.3 (s, 2H, Ar–NH), 10.5 (s,
2H, Ar–NH), 8.8 (s, 4H, Ar–OH), 8.3–7.1 (30H, Ar–H). 13C NMR (DMSO-d6): δ
183.1 (C=O), 179.2 (C=O), 168.5 (C–Cl), 164.6, 142.7 (C–N), 164.2, 129.0 (C=N),
153.2, 144.1 (C–S), 112.0–138.9 (Ar–C). MS (API-ES): m/z=1488.12, found 743.2
([M–2H]2-/2, 495.2 ([M–3H]3-/3), 371.3 ([M–4H]4-/4).
7e: Yield: 42.0%, Rf =0.72. IR (KBr, cm-1): 3420 (N–H and O–H), 1570 (N=N),
1495 (triazine), 1294 (C–N), 1194 (C–O), 1163, 1044 (–SO3H). 1H NMR (DMSO-d6):
δ 15.9 (s, 2H, N–H in hydrazone), 12.8 (s, 2H, Ar–NH), 12.2 (s, 2H, Ar–NH), 10.5 (s,
2H, Ar–NH), 9.0 (s, 4H, Ar–OH), 8.3–7.0 (26H, Ar–H). 13C NMR (DMSO-d6): δ
182.5 (C=O), 178.8 (C=O), 168.7 (C–Cl), 163.6, 142.9 (C–N), 162.5, 129.7 (C=N),
152.9, 149.5, 143.7, 141.9 (C–S), 110.8–138.8 (Ar–C). MS (API-ES): m/z=1807.95,
8

ACCEPTED MANUSCRIPT
found 904.0 ([M–2H]2-/2, 602.8 ([M–3H]3-/3), 451.4 ([M–4H]4-/4).
7f: Yield: 44.2%, Rf =0.66. IR (KBr, cm-1): 3423 (N–H and O–H), 1589 (N=N),
1507 (triazine), 1294 (C–N), 1216 (C–O), 1168, 1045 (–SO3H). 1H NMR (DMSO-d6):
δ 15.7 (s, 2H, N–H in hydrazone), 12.9 (s, 2H, Ar–NH), 12.3 (s, 2H, Ar–NH), 10.5 (s,
2H, Ar–NH), 8.8 (s, 4H, Ar–OH), 8.3–6.9 (28H, Ar–H). 13C NMR (DMSO-d6): δ
182.6 (C=O), 174.7 (C=O), 169.4 (C–Cl), 165.0, 142.9 (C–N), 163.5, 129.2 (C=N),
152.1, 143.7 (C–S), 111.1–136.8 (Ar–C). MS (API-ES): m/z=1576.10, found 788.0
([M–2H]2-/2, 525.3 ([M–3H]3-/3), 393.0 ([M–4H]4-/4).
7g: Yield: 50.7%, Rf =0.77. IR (KBr, cm-1): 3420 (N–H and O–H), 1568 (N=N),
1489 (triazine), 1295 (C–N), 1220 (C–O), 1405, 1141 (–OSO3–), 1365, 1141 (–SO2–),
1165, 1043 (–SO3H). 1H NMR (DMSO-d6): δ 15.8 (s, 2H, N–H in hydrazone), 12.9 (s,
2H, Ar–NH), 12.2 (s, 2H, Ar–NH), 10.9 (s, 2H, Ar–NH), 8.9 (s, 4H, Ar–OH), 8.3–6.9
(28H, Ar–H). 13C NMR (DMSO-d6): δ182.6 (C=O), 178.5 (C=O), 168.3 (C–Cl), 164.0,
142.9 (C–N), 163.7, 129.2 (C=N), 152.6, 143.8, 139.0 (C–S), 111.5–137.7 (Ar–C).
MS (API-ES): m/z=1864.01, found 931.2 ([M–2H]2-/2, 620.8 ([M–3H]3-/3), 465.4
([M–4H]4-/4).
2.2.3 Synthesis of model dye (M1)
Model dye M1 was synthesized by the route depicted in Scheme 3.
Cyanuric chloride (1.90 g, 0.0103 mol) was introduced into 20 g of ice cubes with 2
mL of water and the mixture was stirred at the temperature of 0–5 °C. After stirring
for 30 min, 3.1 g (0.01 mol, 89.2% ) 2-aminobenzene-1,4-disulfonic acid was added.
The temperature of the mixture was maintained at 0–5 °C and pH was maintained at
9

ACCEPTED MANUSCRIPT
4–5 using 10% Na2CO3 aqueous solution. The reaction mixture was stirred for about 2
h until no chromogenic reaction to the Erich reagent was detectable. And then 2.40 g
(0.005 mol) 1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione was added and
the reaction was performed at 40 °C and pH 1–2 using 10% Na2CO3 aqueous solution.
The reaction mixture was stirred for about 3–4 h and TLC was used to monitor the
completion of the reaction (i-PrOH:n-BuOH:EtOAc:H2O, 2:4:1:3, v/v, Rf =0.49).
When the reaction was completed, the mixture was neutralized with sodium carbonate
to pH 6.8–7.0. After addition of potassium acetate (15% w/v), the product was
isolated, then filtered and dried in a vacuum oven at 40 °C (Yield: 83.9%).
IR (KBr, cm-1): 3424 (N–H), 1612 (C=O), 1598, 1506 (C=C), 1560 (N–H), 1485
1
(triazine), 1223 (C–N), 1170, 1040 (–SO3H). H NMR (DMSO-d6): δ 12.4 (s, 2H,
Ar–NH), 10.4 (s, 2H, Ar–NH), 10.2 (s, 2H, Ar–NH), 7.3–8.4 (20H, Ar–H). 13C NMR
(DMSO-d6): δ 182.1 (C=O), 163.6 (C=N), 149.4, 138.4 (C–S), 143.3 (=C–NH),
109.8-136.6 (Ar–C) . MS (API-ES): m/z= 1148.03, found 574.1 ([M–2H]- /2), 381.9
([M–3H]3-/3), 286.4 ([M–4H]4-/4).
2.3 Dyeing and Fixing Process
2.3.1 Dyeing procedure
A dip-pad-steam process was used for the dyeing of cotton with the H-acid
monoazo anthraquinone reactive dyes. Dyeing was carried out at dye concentration of
25 g/L and sodium carbonate concentration of 12 g/L. The cotton was dipped into dye
solution passed between pad rolls once and the pressure on the mangle was adjusted
to give 80% pickup. Then the cotton was dried at 50 °C for 2 min and steamed at
10

ACCEPTED MANUSCRIPT
100 °C for 30 min. Finally, the dyed cotton was washed thoroughly, soaped in 2 g/L
OP-10 solution at 95 °C for 10 min, then washed and dried.
2.3.2 Dye fixation
The dye fixation (F) was calculated using Eq. (1), and the absorbance was
determined using an HP 8453 UV-vis spectrophotometer at the λmax of each dye,
wherein A0, A1 and A2 of the dye liquors were measured with the same volume.
F=(A0 –A1 –A2 )/(A0 –A1 )×100%
(1)
where A0 is the absorbance of the dye bath before dyeing, A1 is the absorbance of
the dye bath after dyeing and A2 is the absorbance of the soap bath after the soaping
step.
2.3.3Measurements
K/S was measured using an Ultra Scan XE Colour Measuring and Matching Meter
(Hunter Co., USA). Wash fastness was assessed using a 5g/L standard soap solution
at 40 °C for 30 min in an S-1002 two-bath dyeing and testing apparatus (Roaches
International Ltd., UK) according to ISO 105-C10:2006. Rub fastness was tested
according to ISO 105-X12:2001 using a Y(B)571-II crockmeter (Darong Standard
Textile Apparatus Co. Ltd., Wenzhou). Light fastness was tested according to ISO
105-B02:1994 using YG(B)611-V light fastness tester (Darong Standard Textile
Apparatus Co. Ltd., Wenzhou). Fading fastness was measured according to ISO
105-A05:1992 using a Digieye colour fastness tester (VeriVide Co., UK).
3 Results and Discussion
3.1 Synthesis and spectral properties of the dyes
11

ACCEPTED MANUSCRIPT
1,4-Dihydroxyanthraquinone can be reduced to 1,4-dihydroxyanthraquinone Leuco
by sodium dithionite in the basic condition. 1,4-Dihydroxyanthraquinone Leuco reacts
much faster with the appropriate aromatic amines to obtain the aromatic amination
products in the presence of boric acid. Therefore, in this work,
1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione
(compound
3)
was
synthesized from 1,4-dihydroxyanthraquinone and 4-aminoacetanilide (Scheme 1).
Then by using compound 3 as diazo component and H-acid derivatives as coupling
components, H-acid monoazo-anthraquinone reactive dyes 7a–g were synthesized,
respectively. The synthesis route of H-acid monoazo-anthraquinone reactive dyes is
shown in Scheme 2 and the spectral data of H-acid monoazo-anthraquinone reactive
dyes in water are listed in Table 1.
---Insert Scheme 1---
---Insert Scheme 2---
In Table 1, the maximum absorption wavelengths of H-acid
monoazo-anthraquinone reactive dyes, of which half-band widths were about 200 nm,
were between 583 and 596 nm with dark blue shades in water and the dyes exhibited
high molar absorption coefficients ranging from 27,800 to 38,700 L·mol-1·cm-1.
---Insert Table 1---
The synthesized H-acid monoazo-anthraquinone reactive dyes contained two
chromophores
of
red
H-acid
monoazo
chromophore
and
green
1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione chromophore. Theoretically,
the colours of the synthesized dyes should be the assorted colours of red and greenꢀas
12

ACCEPTED MANUSCRIPT
a result of the intramolecular combination of two chromophores. But this kind of dyes
showed surprising blue colour, which was completely different from the assorted
colour . Dyeing experiments were conducted on cotton fibres, and Fig. 1 displays the
digital photos of the fabrics dyed with H-acid monoazo-anthraquinone reactive dyes,
which also proved that the colour of this kind of dyes was blue.
---Insert Fig. 1---
In order to explain the surprising phenomenon, the model dye M1 was synthesized
from 1,4-bis ((4-aminophenyl) amino) anthrancene-9,10-dione by the route depicted
in Scheme 3 and the model dye M2 (C.I. Reactive Red 253) was a commercial one.
The spectral data of model dyes M1 and M2 in water are presented in Table 2.
---Insert Scheme 3---
---Insert Table 2---
From Table 2, we can see M1 in water had two maximum absorption wavelengths
of 637 nm and 448 nm, which was a green dye with the molar absorption coefficient
of 12700 and 8100 L·mol-1·cm-1, respectively, whereas M2 had the maximum
absorption wavelength of 540 nm, which was a red dye with the molar absorption
coefficient of 25400 L·mol-1·cm-1.
Since the synthesized blue dyes contained one anthraquinone and two azo
chromophores, the model dyes M1 and M2 were mixed in the mole ratio of 1:2. The
UV-vis absorption spectra of M1 and M2 and the mixed solution with
previously mentioned mole ratio are shown in Fig. 2. As is shown, the absorption
spectra of the mixed solution of model dyes M1 and M2 presented the characteristic
13

ACCEPTED MANUSCRIPT
absorption spectra of two kinds of dyes with assorted magenta colour. However,
H-acid monoazo-anthraquinone reactive dyes in water only had one maximum
absorption wavelength of about 590 nm as shown in Fig. 3. Although the half-band
widths were wide [13,15], the characteristic absorptions of red dyes at 540 nm or
green dyes at 448 nm still could not be found. It proved that the intramolecular
combination of two chromophores did not result in the blue color. The blue colour
may result from the chang of the dye structure.
---Insert Fig. 2---
---Insert Fig. 3---
3.2 Characterization of the dyes
In order to thoroughly explain the surprising phenomenon, the structures of the
1
dyes were characterized by IR, H NMR and 13C NMR. The IR spectra of dye 7a,
compound 3 and M2 are shown in Fig. 4. The characteristic absorption peaks of the
hydroxyl group and amino group were observed to overlap at 3417 cm-1. The
absorption band at 1568 cm-1 indicated the presence of N=N, whereas the absorption
band created by the s-triazine ring appeared at 1485 cm-1. The characteristic
absorption peaks at 1295 cm-1 and 1195 cm-1 indicated the existence of C–N and C–O
of the aromatic ring, respectively. The absorption bands at 1165 cm-1 and 1041 cm-1
were assigned to S=O of sulfonate groups. Meanwhile, it clearly demonstrated that
compared with IR spectrum of compound 3, the intensity of absorption band of
carbonyl group at 1614 cm-1 became weaker, indicating the change of the carbonyl
group.
14

ACCEPTED MANUSCRIPT
---Insert Fig. 4---
1
The representative H NMR spectra of dye 7a, compound 3 and M2 are shown in
Fig. 5. The signals at 7.2–8.3 ppm were assigned to the aromatic protons. The imino
protons of the aromatic ring showed signals at 12.3–12.7 and 10.5 ppm. The signal at
8.8 ppm was assigned to the hydroxyl proton of the phenol group. Compared with 1H
NMR spectrum of compound 3, no significant absorption of amino protons (5.2 ppm)
could be observed due to the diazo reaction of compound 3. In addition, the azo
linkages of dye 7a existed predominantly in the hydrazone form (15.8 ppm) due to the
intramolecular hydrogen bonding with an adjacent hydroxyl group, which also
1
appeared in H NMR spectrum of dye M2. This is atttibuted to the transformation
between azo and hydrazone structures [Scheme 4(a)] [16]
---Insert Fig. 5---
In addition, according to the proton peak areas of hydrazone group (IN-H =1.00) and
aromatic ring (IAr-H =25.03), it can be calculated that the proton peak area of hydroxyl
group in azo form (Ia =0.78) is smaller than that of the whole dye 7a (IO-H =0.99).
There was a surplus hydroxyl proton peak due to the isomerization of carbonyl groups
on the anthraquinone ring, which confirmed the previous results obtained from the IR
spectra (the intensity of absorption band of carbonyl group at 1614 cm-1 became
weaker). It could also prove the transformation of dye 7a between hydroxybenzene
and benzoquinone structures [Scheme 4(b)] [17].
---Insert Scheme 4---
---Insert Fig. 6---
15

ACCEPTED MANUSCRIPT
13
Fig. 6 shows the representative C NMR spectra of dye 7a, compound 3 and M2.
As can be seen, the signals at 119.5-138.8 ppm were assigned to the aromatic carbons
and the carbon of C–Cl bond showed signal at 168.6 ppm. The presence of a signal at
185.0 ppm suggested a hydrazone form [Scheme 4(a)] [16], which was the same with
dye M2.
Compared with 13C NMR spectrum of compound 3, the signal of carbonyl carbon
of dye 7a shifted to the lower field at 174.2 ppm due to the tautomerism between
hydroxybenzene and benzoquinone structures [Scheme 4(b)] [17], further confirming
the results obtained from 1H NMR. As a result, a new conjugated system formed
between the anthraquinone ring and the phenyl azo linkage. This can clarify the
reason why the synthesized dyes are blue.
3.3 Theoretical calculations
In order to add better understanding to the surprising phenomenon, DFT
calculations have been carried out to optimize the structure of the dye molecules. All
calculations in this work were performed at the level of B3LYP/6-31G*, as planted in
Gaussion 09 program [18]. Subsequent vibration frequency analyses were preformed
for confirmation of the optimized structure as a minimum (Nimag = 0). The maximum
absorption wavelengths of these dyes were calculated by energy information of the
optimized molecular geometry configuration [19].
---Insert Fig. 7---
---Insert Table 3---
The
optimized
molecular
geometry
configuration
of
H-acid
16

ACCEPTED MANUSCRIPT
monoazo-anthraquinone reactive dye 7a is shown in Fig. 7. The structure shows a
planar configuration of the anthraquinone core part in the dye molecule. The
optimized geometrical parameters were collected in Table 3. As shown in this table,
C5−N2 and C8−N1 bond length were between C−N single bond (1.39 Å in compound 3)
and C=N double bond (1.29 Å) [20-21], demonstrating the conjugate characteristics.
The C10−O2 and C9−O1 bond length were longer than C=O double bond (1.23 Å in
compound 3) and shorter than C−O single bond (1.35 Å) [22], in response to the
construction of conjugated system resulted from the contraction of C5−N2 and C8−N1
bonds. In addition, The N1−H1 and N2−H2 bond length (1.024 Å) were longer than
those in compound 3 (1.012 Å). Such changes in the C−N, C−O and N-H bonds could
be associated with the isomerization evidenced by the 1H NMR and 13C NMR spectra
aforementioned.
---Insert Table 4---
---Insert Fig. 8---
The energies of the frontier molecular orbital of the optimized configuration is
shown in Table 4. The HOMO and LUMO energy levels of the dye molecules are
calculated to be −0.21 and −0.13 a.u., respectively, deducing a HOMO−LUMO
energy gap of 0.077 a.u.. The maximum absorption wavelength was calculated to be
ca. 587−591 nm. This indicates that H-acid monoazo-anthraquinone reactive dyes are
a kind of blue dyes. The isosurfaces of HOMO and LOMO of 7a are shown in Fig. 8.
The results demonstrate that a new conjugated system formed between the
anthraquinone ring and the phenyl azo linkage. The absorption maxima of dyes appear
17

ACCEPTED MANUSCRIPT
to be determined primarily by the conjugated system, which consists of an
anthraquinone, two phenyl azo linkage and H-acid. These results support the
experimental observation that the blue colour resulted from the newly formed larger
conjugated system rather than from the intramolecular combination of two
chromophores (anthraquinone and H-acid monoazo moieties).
In addition, since the anthraquinone chromophore was combined with relatively
short p-conjugated systems, the dyes showed long wavelength absorption bands. This
can explain the phenomenon of the wide half-band widths of the dyes [15].
3.4 Dyeing properties
Dip-pad-steam dyeing process is an important process in dyestuff industry. For this
kind of dyes to finish cotton, a dip-pad-steam dyeing process was used and
“one-dip-one-nip” dyeing method was proved to be a suitable process [23].
Fixation and fastness properties of the H-acid monoazo-anthraquinone reactive
dyes are shown in Table 5. The fixation could reach over 88% and K/S of the dyed
cotton could reach a 1:1 colour depth according to ISO 105-A01-2010. The light
fastness reached 5 grade, which was the same with that of the anthraquinone reactive
dye M1, while traditional monoazo reactive dye M2 dyed on cotton only have 4 grade
light fastness [24]. It indicated that the anthraquinone structure could improve the
light fastness of two H-acid monoazo structure dyes. Furthermore, the wash and dry
rub-fastness could reach 4 grade and 4−5 grade, respectively. These features brought
very promising future applications for this kind of dyes.
---Insert Table 5---
18

ACCEPTED MANUSCRIPT
4 Conclusions
A new kind of H-acid monoazo-anthraquinone reactive dyes was obtained by using
1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione as diazo component and
H-acid derivatives as coupling components. All the dyes were characterized by
UV-vis, IR, MS, 1H NMR and 13C NMR. The results showed that the synthesized dyes
1
were blue with the maximum absorption peak at about 590 nm. H NMR and 13C
NMR analysis and DFT calculations revealed that a new conjugated system formed
between the anthraquinone ring and the phenyl azo linkage and the blue colour
resulted from the newly formed larger conjugated system rather than from the
intramolecular combination of two chromophores. The fixations of the dyes on cotton
were over 88% and the light fastness reached 5 grade. Compared with the
corresponding azo dyes, the dyed fabrics of this kind of dyes showed good light
fastness. All these results will provide a new way for the synthesis of reactive dyes
with a new blue chromophore and excellent dyeing properties.
Acknowledgement
This work is supported by the Science Fund for Creative Research Groups of the
National Natural Science Foundation of China (Grant No.21421005), Ministry of
Education (the Ministry of Education Innovation Team, IRT-13R06) and Dalian
University of Technology (Dalian University of Technology Innovative Research
Team, DUT2013TB07).
Reference
[1]
D
M
Lewis,
A
A
Siddique. Synthesis of reactive dyes based on the bis-
19

ACCEPTED MANUSCRIPT
(N-carboxymethylamino)monoquaternarytriazine-bis-ethylsulphone reactive group. Part 1:
Application to cotton cellulose. Color Technol 2006;122:217–226.
[2] Yingling Li, Shufen Zhang, Jinzong Yang, Song Jiang, Qian Li. Synthesis and application of novel
crosslinking polyamine dyes with good dyeing performance. Dyes Pigments 2008;76:508–514.
[3] Karl Bredereck, Christian Schumacher. Structure reactivity correlations of azo reactive dyes based
on H-acid. IV. Investigations into the light fastness in the dry state, in the wet state, and in
presence of perspiration. Dyes Pigments 1993;23:135–147.
[4] Zs Csepregi, P Aranyosi, I Rusznak, L Toke, J Frankl, A Vig. The Light Stability of Azo Dyes and
Azo Dyeings I. Light Stability of Dyeings with Reactive and Non-reactive Derivatives,
Respectively, of Two Selected Azochromophores. Dyes Pigments 1998;37:1–14.
[5] Toshio Hihara, Yasuyo Okada, Zenzo Morita. Relationship between photochemical properties and
colour fastness due to light-related effects on monoazo reactive dyes derived from H-acid, g-acid,
and related naphthalene sulfonic acids. Dyes Pigments 2004;60:23–48.
[6] W J Epolito, Y H Lee, L A Bottomley, S G Pavlostathis. Characterization of the textile
anthraquinone dye Reactive Blue 4. Dyes Pigments 2005;67:35–46.
[7] Haofei Huang, Wei Ma, Bingtao Tang, Shufen Zhang. Properties of a novel acid dye
1-amino-4-[(6-nitro-2-benzothiazolyl)amino]-9,10-anthraquinone-2-sulfonic acid with anti-UV
capability. Chin Chem Lett 2010;21:417–420.
[8] Eunmi Kim, Jaehong Choi. Synthesis of Cationized Anthraquinone Dyes and Their Dyeing
Properties for meta-Aramid Fiber. Fiber Polymer 2013;14:2054–2060.
[9] Masaki Matsui, Anang Sedyohutomo, Masashi Satoh, Yasuo Abe, Kazumasa Funabiki, Hiroshige
Muramatsu, et al. Solubility and decomposition temperature of 1,4-bis(arylamino)anthraquinone
20

ACCEPTED MANUSCRIPT
dyes. Dyes Pigments 1998;40:21–26.
[10] Klaus Korte. Anthraquinone azo dyes and use of such compounds. Switzerland: US6696553B1,
2004.
[11] Baettig Kurt, Moigno Damien. Water soluble and water fast dyes for ink jet printing. Switzerland:
WO 2013139485A1, 2013.
[12] Jae Bok Chang, Sim Bum Yuk, Jong S Park , Jae Pil Kim. Dichroic and spectral properties of
anthraquinone-based azo dyes for PVA polarizing film. Dyes Pigments 2011;7:737–744.
[13] Zhibin Cai, Jianrong Gao, Xiaonian Li. Synthesis and third-order optical nonlinearities of
anthracenedione derivatives. Dyes Pigments 2007;74:494–500.
[14] Dipak K Palit, Haridas Pal, Tulsi Mukherjee, Jai P Mittal. Photodynamics of the S, State of some
Hydroxy- and Am ino-su bstituted Naphthoqu inones and Anth raqu inones. J Chem Soc. Faraday
Trans, 1990;86:3861–3869.
[15] Denis Jacquemin, Julien Preat, Valerie Wathelet, Jean-Marie Andre, Eric A Perpete. Substitution
effects on the visible spectra of 1,4-diNHPh-9,10-anthraquinones. Chem Phys Lett
2005;405:429–433.
[16] Karl Bredereck, Christian Schumacher. Structure Reactivity Correlations of Azo Reactive Dyes
Based on H-acid. I. NMR Chemical Shift Values, pKa Values, DyesM Aggregatiou and Dyeing
Behaviour. Dyes Pigments 1993;21:23–43.
[17] Pod Erik Hansen, Alois Kolonicny, Antonin Lycka. Deuterium Isotope Effects on 13C Nuclear
Shielding of Amino and Acetamido Compounds. Tautomerism and Intramolecular Hydrogen
Bonding. Magn Reson Chem 1992;30:786–795.
[18] Xiaowei Jiao, Hang Yu, Qingwei Kong, Yi Luo, Qiang Chen, Jingping Qu. Theoretical
21

ACCEPTED MANUSCRIPT
mechanistic studies on the degradation of alizarin yellow R initiated by hydroxyl radical. J Phys
Org Chem 2014;27:519–526.
[19] Quanquan Shi, Ru Sun, Jianfeng Ge, Qingfeng Xu, Najun Li, Jianmei Lu. A comparative study of
symmetrical and unsymmetrical trimethine cyanine dyes bearing benzoxazolyl and benzothiazolyl
groups. Dyes Pigments 2012;93:1506–1511.
[20] John O Morley. Theoretical Study of Tautomerism in the Reduced Forms of 1,4-Disubstituted
Anthraquinones. J Phys Chem 1995;99:5956–5960.
[21] A V Yatsenko, V A Tafeenko, V N Zakharov, S I Popovb, H Schenk. An INDO/S Study of the
Second π π* Transition in the Spectra of 1,4-Diaminoanthraquinones Responsible for their Green
Hue. Dyes Pigments 1998;37:273–282.
[22] M L Ferreiro, J Rodriguez-Otero. Ab initio study of the intramolecular proton transfer in
dihydroxyanthraquinones. J Mol Struct-Theochem 2001;542:63–67.
[23] Yong Deng, Bingtao Tang, Hongjuan Zhao, Jiping Xu, Jinqiu Xiao, Xingrong Zhang, Hua Xu,
Shufen Zhang. Dyeing method and properties of polymaleic acid dyes on cotton. Color Technol
2012;129:144–149.
[24] The Society of Dyers and Colourists, American Association of Textile Chemists and Colorists.
Colour Index. Third Edition (Second Revision), Volume 7; 1982.
22

ACCEPTED MANUSCRIPT
Fig. 1. Digital photos of the fabrics dyed with H-acid monoazo-anthraquinone reactive dyes
Fig. 2. UV-vis absorption spectra of M1 and M2 and the mixed solution with mole ratio of M1 to
M2 1:2 in water (M1: 1.5×10-5 mol·L-1, M2: 3.0×10-5 mol·L-1)
Fig. 3. UV-vis absorption spectra of dye 7a and model dyes M1 and M2 at the concentration of
3.0×10-5 mol·L-1 in water
Fig. 4. IR spectra of dye 7a, compound 3 and M2
Fig. 5. 1H NMR spectra of dye 7a, compound 3 and M2 in DMSO-d6
Fig. 6. 13C NMR spectra of dye 7a, compound 3 and M2 in DMSO-d6
Fig. 7. Optimized molecular geometry configuration of dye 7a
Fig. 8. The electron clouds of HOMO (a) and LOMO (b) of dye 7a
Scheme 1. Synthesis procedure of 1,4-bis((4-aminophenyl)amino)anthrancene-9,10-dione
(compound 3)
Scheme 2. Synthesis procedure of H-acid monoazo-anthraquinone reactive dyes(7a–g)
Scheme 3. Synthesis procedure of the model dye M1
Scheme 4. Two kinds of tautomerisms in H-acid monoazo-anthraquinone reactive dyes

ACCEPTED MANUSCRIPT
Table 1
Structures and spectral data of H-acid monoazo-anthraquinone reactive dyes.
εmax×104
(L·mol-1·cm-1)
λmax (nm)
Dye
-Ar
△ν1/2 (nm)
（H2O）
7a
3.25
3.65
596
215
7b
591
211
7c
3.32
3.12
591
595
176
204
7d
SO3H
7e
3.87
583
200
HO3S
7f
2.78
3.03
591
594
213
229
7g
Table 2
Structures and spectral data of model dyes M1 and M2.
λmax
εmax×104
(L·mol-1·cm-1)
Dyes
Structure
( nm)
△ν1/2(nm)
（H2O）
1.27
0.81
637
448
154
-
M1

ACCEPTED MANUSCRIPT
M2
2.54
540
88
Table 3
Comparison of some calculated bond lengths (Å) of H-acid monoazo-anthraquinone reactive dyes.
Dyes
7a
7b
7c
C5−N2 and C8−N1
1.380
C10−O2 and C9−O1
1.244
N1−H1 and N2−H2
1.024
1.380
1.244
1.024
1.380
1.244
1.024
7d
7e
1.379
1.244
1.024
1.380
1.244
1.024
7f
1.380
1.244
1.024
7g
3
1.380
1.244
1.024
1.391
1.231
1.012
Table 4
Energy information of the optimized molecular geometry configuration of H-acid
monoazo-anthraquinone reactive dyes.
Dyes
7a
7b
7c
E(a.u.)
LUMO(a.u.)
−0.13830
−0.13327
−0.13700
−0.13414
−0.13535
−0.13652
−0.13809
−0.08191
HOMO(a.u.)
−0.21588
−0.21064
−0.21439
−0.21124
−0.21292
−0.21389
−0.21548
−0.16692
L-H(a.u.)
0.07758
0.07737
0.07739
0.07710
0.07757
0.07737
0.07739
-
λm(nm)
587.78
589.38
589.22
591.44
587.86
589.38
589.22
-
−8304.25041
−8304.25105
−8304.24812
−7056.66916
−9551.82516
−7433.81698
−9558.63608
−1372.26219
7d
7e
7f
7g
3
Table 5
Fixation and fastness properties of H-acid monoazo-anthraquinone reactive dyes.a
Rub-fastness Wash-fastness
Dry wet cotton
Dyes
F(%)
K/S
Light-fastness
change
wool

ACCEPTED MANUSCRIPT
7a
7b
7c
7d
7e
7f
93.4
88.4
91.8
88.8
88.2
88.3
89.9
14.0
11.2
12.8
9.4
5
5
4−5
4
4
4
4
4
4
4
4
4−5
4
4−5
4−5
4−5
4−5
4−5
4−5
4−5
4−5
4−5
4−5
4−5
4−5
4−5
4−5
5
4−5
4
4−5
4
4−5
5
11.0
10.1
10.2
4
4
4−5
4
4
7g
4−5
4
4−5
a Dye concentration 25 g/L; Sodium carbonate concentration 12 g/L; 100 °C/30 min steaming.

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT