Model Compounds for the Photochemical Study
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H 2 N N H 2 N NH H 2 N N H 2 N O H 2 N N HO O 2-AM INO IND AM INE (PPD /M PD ) 2-AM INO IN DO ANILINE (PPD /M AP) 2-AM IN O IN DO PHEN O L (PAP/M AP) HO N H 2 N O G REEN DYE FRO M PPD /RESO RCINOL NH NH 2 N H 2 N N BANDRO W SKI'S BASE NH 2 NH 2 NH 2 del Compounds for the Photochemical St
description
Model Compounds for the Photochemical Study. Mechanism of Coupling Reaction. Primary factors controlling the overall reaction need to be understood. Possible approaches include, -Electrochemical oxidation/spectroelectrochemistry -Radiolysis to identify reaction kunetics and mechanism - PowerPoint PPT Presentation
Transcript of Model Compounds for the Photochemical Study
H2N
N
H2N NH H2N
N
H2N O H2N
N
HO O
2-AMINOINDAMINE(PPD/MPD)
2-AMINOINDOANILINE(PPD/MAP)
2-AMINOINDOPHENOL(PAP/MAP)
HO
N
H2N O
GREEN DYE FROM PPD / RESORCINOL
NH
NH2
N
H2N N
BANDROWSKI'S BASE
NH2
NH2
NH2
Model Compounds for the Photochemical Study
NH2
NH2
OX
NH
NH
NH
NH
H2N NH2
+
H2N
NH
H2N NH2
H2N
N
H2N NHH2N
NH
H2N NH2
OX
Mechanism of Coupling Reaction
Primary factors controlling the overall reaction need to be understood.
Possible approaches include,-Electrochemical oxidation/spectroelectrochemistry-Radiolysis to identify reaction kunetics and mechanism-Medium effects on the reaction kinetics-Identify propagating or quenching reactions
– Substituent groups alter the dye color– pH can bring about significant changes
in the coloration– oleic acid serves as both buffering
agent & surfactant– high surfactant concentration is
known to minimize the amount of water which in turn favors the local peroxide concentration
Medium Effects
H3N
N
H2N NH2 H2N
N
H2N NH2 H2N
N
H2N NH
red blue red
pKa 10.4pKa 3.4
Reactive DyesNaO3SOCH2CH2S N=N
O
OH
NH2
SO3Na
SO3NaNaO3SOCH2CH2S
O
N=N
Remazol Black B
200 300 400 500 600 7000.0
0.2
0.4
0.6
0.8
1.0
f ed c
b
a
Abs
orba
nce
Wavelength, nm
Or Reactive Black 5Sonolytic Degradation
Vinodgopal & Kamat, Water Research, 1998, 32,3646-3650
Background information on dyeing of wool and other fibers with reactive dyes may be useful in considering alternate systems
