- Synthesis and characterization of polyurethanes of isophorone diisocyanate containing bis(azo) and bis(o-nitrobenzyl) chromophores in the main chain
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A series of photosensitive polyurethanes containing bis(azo) and bis(o-nitrobenzyl) groups were synthesized by polyaddition reactions of diols such as bis(4-hydroxyphenylazo)-2,2'-dinitrodiphenylmethane, 4-hydroxy-3-methylphenylazo-4'-hydroxy-phenylazo-2,2'-dinitrodiphenylmethane and bis(4-hydroxy-3-methylphenylazo)-2,2'-dinitro-diphenylmethane with isophorone diisocyanate, in dimethyl acetamide in presence of di-n-butyltin dilaurate as catalyst. All of them were characterized by IR, UV-vis, 1H and 13C NMR spectra and also by differential scanning calorimetry and gel permeation chromatography.
- Kumar, K. Sudheesh
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scheme or table
p. 2705 - 2708
(2012/01/19)
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- Synthesis, antimicrobial activity and application of some novel quinazolinone based monoazo reactive dyes on various fibres
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The main target of this paper was to synthesize novel reactive dyes that not only give good dyeing property but also show pharmacological activity i.e. antimicrobial activity (antibacterial and antifungal). In this regard ten novel monoazo quinazolinone based reactive dyes (7a-j) were made by coupling of diazotised 3-{4-[4-amino-2-nitrobenzyl]-3-nitrophenyl}-7-chloro-2- phenylquinazolin-4(3H)-one (4) with various p-chloro anilino cyanurated coupling components (6a-j). The structures of all these synthesized dyes were confirmed by elemental analysis and spectral methods. The antimicrobial activity, colorimetric data, solvent effect and fastness properties of these dyes were also investigated.
- Patel, Divyesh R.,Patel, Keshav C.
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experimental part
p. 1 - 10
(2011/12/02)
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- Synthesis and photoreactions of aromatic diols containing bis (azo) and bis (o-nitrobenzyl) chromophores
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Aromatic diols containing bis (azo) and bis (o-nitrobenzyl) chromophores viz., (4-hydroxyphenylazo)-2,2′-dinitrodiphenylmethane, 4-hydroxy-3-methylphenylazo-4′-hydroxyphenylazo-2,2′- dinitrodiphenyl methane and bis (4-hydroxy-3-methylphenylazo)-2-dinitrodiphenyl methane were synthesized from 4,4-diamino-2,2′-dinitrodiphenylmethane and phenol/O-cresol. As a result of photolysis, the azo group of the diols unergo trans-cis isomerisation and one of the o-nitrobenzyl groups of the diols undergo trans-cis isomerisation and one of the o-nitrobenzyl groups in them undergo redox reaction to nitronitrosocarbinol. There occurred a solubility difference between the irradiated and unirradiated diol. In solution, a photoswtiching behaviour was also observed.
- Sudheesh Kumar
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experimental part
p. 1393 - 1399
(2011/10/19)
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- Chiral polyesters with azobenzene moieties in the main chain, synthesis and evaluation of nonlinear optical properties
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The synthesis, characterization and evaluation of nonlinear optical properties of a new series of chiral copolyesters containing push-pull electronic azobenzene mesogenic groups in the main chain are reported. The copolyesters showed liquid crystalline behaviour with high glass transition temperatures (~200 °C), stable liquid crystalline mesophases (up to 360 °C) and high second harmonic generation (SHG) efficiency. The second order nonlinear susceptibility values were measured as a function of the percentage of the chiral building unit and the temporal stability was found to be significant over a long duration of time.
- Bahulayan, Damodaran,Sreekumar, Krishnapillai
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p. 1425 - 1429
(2007/10/03)
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