Synthesis and colour evaluation MARIA E. GRAD, 1 * GEORGETA M. SIMU 2 - - PowerPoint PPT Presentation

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Nov 06, 2023 574 likes •689 views

Disazo symmetrical stilbene dyes. Synthesis and colour evaluation MARIA E. GRAD, 1 * GEORGETA M. SIMU 2 , SIMONA G. MUNTEAN 1 1 Institute of Chemistry Timioara of the Romanian Academy, B-dul Mihai Viteazul 24, RO- 300223 Timioara, Romania 2

SLIDE 1

Disazo symmetrical stilbene dyes. Synthesis and colour evaluation

MARIA E. GRAD,1* GEORGETA M. SIMU2, SIMONA G. MUNTEAN1

1Institute of Chemistry Timişoara of the Romanian Academy,

B-dul Mihai Viteazul 24, RO-300223 Timişoara, Romania

2University of Medicine and Pharmacy Victor Babeş Timişoara,

Faculty of Pharmacy, Piata Eftimie Murgu 2-4, RO-30003 Timişoara, Romania *e-mail : marilena_grad@yahoo.com

SLIDE 2

The synthesis of two new symmetrical disazo direct dyes containing 4,4'-diaminostilbene-2,2'disulphonic acid as middle component and 3-chlorosalicylanilide and 4-chlorosalicylanilide as coupling components The synthesized dyes were analyzed by thin layer chromatography (TLC), VIS, FT/IR and 13C-NMR spectroscopy, and HPLC technique. The synthesized dyes were analyzed by means of the CIELAB parameters under the CIE recommended conditions: D65 /10°, A /10° , F2/10° The colour difference (ΔEab*) was calculated against one white standard (P.W.6; C.I.77 .891)

AIM

SLIDE 3

CH CH N N SO3H HO3S N N

Ar Ar 1 7 6 5 2 3 4

where the couplings components Ar for the azo-stilbene dyes are;1 (for dye I); 2 (for dye II);

OH CONH 1' 2' 3' 4' 5' 6' 7' 8' 9' 10' 11' Cl 12' 13' OH CONH 1' 2' 3' 4' 5' 6' 7' 8' 9' 10' Cl 11'

1 2 Scheme 1 Structures of the azo-stilbene dyes I and II (the atoms position for 13C–NMR spectrum)

SLIDE 4

13C-NMR rspectrum for the dye I (detail)

SLIDE 5

Jasco,C18, 83% aqueous MeOH Isocratic elution

5000 10000 15000 20000 25000 2 4 6 8 10 12 timp de retentie (min) semnal detector (471 nm)

Chromatogram for dye II

SLIDE 6

Colour measurements for the dye I compared to the white standard

SLIDE 7

Colour measurements for the dye II compared tot the white standard

SLIDE 8

The reflectance curve of the azo-stilbene dye I (2% dye concentration, D65 illuminant, 10° observer)

SLIDE 9

The reflectance curve of the azo-stilbene dye II (15% dye concentration, A illuminant, 10° observer)

SLIDE 10

Two new disazo symmetrical direct dyes containing 4,4’-diaminostilbene-2,2'-disulphonic acid as middle component and 3-chlorosalicylanilide and 4-chlorosalicylanilide as coupling components were synthesized and characterized. The spectroscopy data (VIS, FT/IR, 13C-NMR), the chromatographic data (TLC and HPLC) and the colour analysis data (CIELAB) confirm the proposed chemical structures for the synthesized dyes. The colour differences (ΔEab*) calculated against one standard reveal a good colouring power of the studied dyes