- Synthesis and electrooptical properties of metal-containing azopolymers. The influence of steric factors on the electro-optical effect in polycomplexes of azobenzene derivatives with cobalt
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We propose new structures of metal-containing azopolymers with changeable electro-optical properties in consequence of different coordination metal ions. The new monomers - 4-methacroyloxy-(4'-carboxy-3'-hydroxy)-azobenzene, 4-methacroyloxy-2'-carboxy-azobenzene and their complexes with Co and polymers based of these ones are synthesized. The influence of the electric field on the absorption spectra of new metal-containing azopolymers films are investigated. Electro-optical properties of polymeric films is determined by the re-orientation of dipole moments of azobenzene groups photo induced by polarized light in the electric field. Increase of structural inflexibility by the photo isomerization of azobenzene groups decrease the electro-optical effect value.
- Savchenko, Irina,Davidenko, Nikolaj,Davidenko, Irina,Popenaka, Anatolij,Syromyatnikov, Vladimir
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experimental part
p. 254/[1002]-262/[1010]
(2009/10/11)
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- Azobenzene derivatives as labeling agents and intermediates thereof
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A compound of the formula I: wherein R is H or —N═N-2-carboxyphenyl; A is (CH2)nor —CH═CH—, wherein n is an integer from 0 to 10, or A may also be —CH(COOH)— when R is —N═N-2-carboxyphenyl; and X is a radical selected from the group consisting of: (i) Cl; (ii) COOR1, wherein R1is p-nitrophenyl or N-succinimidyl; (iii) CONH—NHR2, wherein R2is H, COO(t-butyl) or COObenzyl; (iv) CONH—[B]—NHR3, wherein R3is H, COOR1, or CO—[B′]—maleimido, wherein R1is t-butyl, p-nitrophenyl or N-succinimidyl, and B and B′, the same or different, are (CH2)nwherein n is an integer from 2 to 10; (v) CONH—[B]—COOR4, wherein R4is H, C1-C8alkyl, N-succinimidyl; (vi) CONH—[B]—OH; (vii) CONH—[B]—CONH—NHR2, wherein R2is H, COO(t-butyl) or COObenzyl; and (viii) NHR2, wherein R2is H, COO(t-butyl) or COObenzyl, when A is —CH(COOH)— and R is —N═N-2-carboxyphenyl. The 4′-hydroxyazobenzene-2-carboxylic acid (HABA) compounds are novel reagents for labeling, isolation and detection of biological molecules.
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- Low excitation energy band of 4-hydroxyazobenzene derivatives
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The low excitation energy band appeared in the electronic spectra of some 4-hydroxyazobenzene derivatives is assigned to an electronic transition of the type η-?*.It is concluded that 4-hydroxyazobenzene derivatives exist mainly in the true azo form.On the other hand, the visible spectra of the azo compound; 4-hydroxy-2-carboxyazobenzene is interpreted on the basis that this compound exists in a tautomeric equilibrium of the type azo hydrazone, originating from the carboxyl group at the ortho position to the azo one.
- Mahmoud, M. R.,Ibrahim, S. A.,Hamed, M. A.
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p. 729 - 734
(2007/10/02)
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