The effects of cyclic terminal groups in aminoazobenzene dyes*

Hallas, G.

doi:10.1111/j.1478-4408.1994.tb01594.x

Cited by 9 publications

(1 citation statement)

References 32 publications

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“…Accordingly, a significantly increasing bathochromic effect can be noted for both the bands of polymeric and monomer derivatives on passing from R = H to CN and NO 2 (Table 2 and Figure 4), as a consequence of the increasing electron‐withdrawing capability of the substituent and hence of the conjugation extent in the aromatic chromophore,20 giving rise to a progressive reduction of the electronic transition energy in the system. It can be therefore deduced that the nitro substituent in 4′ position of the bisazoaromatic moiety provides the highest charge delocalization in the investigated systems.…”

Section: Resultsmentioning

confidence: 97%

New Optically Active Methacrylic Polymers Bearing Side‐Chain Bisazoaromatic Moieties

Angiolini

Benelli

Giorgini

et al. 2007

Macro Chemistry & Physics

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The synthesis of three novel optically active monomers containing a side‐chain chiral moiety linked to a photochromic bisazoaromatic chromophore, such as (S)‐3‐methacryloyloxy‐1‐[4′‐phenylazo‐(4‐azobenzene)]‐pyrrolidine [(S)‐MPAAP], (S)‐3‐methacryloyloxy‐1‐[4′‐cyanophenylazo‐(4‐azobenzene)]‐pyrrolidine [(S)‐MPAAP‐C] and (S)‐3‐methacryloyloxy‐1‐[4′‐nitrophenylazo‐(4‐azobenzene)]‐pyrrolidine [(S)‐MPAAP‐N], is described. Each monomer has been radically homopolymerized to afford the corresponding optically active polymeric derivative, which have been characterized, in solution and in the solid state, and their properties compared to those of the monomers and of analogous homopolymers bearing only one azoaromatic chromophore in the side chain. The optical activity displayed by the polymers is discussed in terms of extent of chiral conformation assumed by the macromolecules as a consequence of their stiffness and the dipole‐dipole interactions between the bisazoaromatic chromophores.magnified image

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Section: Resultsmentioning

confidence: 97%

New Optically Active Methacrylic Polymers Bearing Side‐Chain Bisazoaromatic Moieties

Angiolini

Benelli

Giorgini

et al. 2007

Macro Chemistry & Physics

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Synthesis and chiroptical properties of optically active photochromic methacrylic polymers bearing in the side chain the (S)-3-hydroxypyrrolidinyl group conjugated with thetrans-azoaromatic chromophore

Angiolini

Caretti

Giorgini

et al. 1999

J. Polym. Sci. A Polym. Chem.

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Novel optically active polymethacrylates, namely poly[(S)‐3‐methacryloyloxy‐1‐(4‐azobenzene)pyrrolidine] and poly[(S)‐3‐methacryloyloxy‐1‐(4′‐nitro‐4‐azobenzene)pyrrolidine], have been synthesized by radical polymerization of the corresponding monomers, prepared in turn through a synthetic route preserving the asymmetric center by any racemization reaction. These homopolymers are characterized by the presence in the side chain of an optically active pyrrolidinyl ring linked to the trans‐azoaromatic system through the nitrogen atom. The optical activity of the polymers in solution appears much higher than that observed with the low molecular weight models, purposely synthesized for comparison. Circular dichroism spectra of the synthesized products demonstrated that, in solution, the macromolecules assume highly homogeneous conformations with a prevailing chirality to a larger extent with respect to analogous systems previously investigated. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3257–3268, 1999

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Recent developments in colorants for textile applications

Holme¹

2002

Surface Coatings International Part B: Coatings Transactions

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The effects of cyclic terminal groups in aminoazobenzene dyes*

Abstract: The changes brought about by variations in ring size of cyclic terminal groups in aminoazobenzene dyes are described and discussed, with particular emphasis on spectroscopic behaviour.

Cited by 9 publications

References 32 publications

New Optically Active Methacrylic Polymers Bearing Side‐Chain Bisazoaromatic Moieties

New Optically Active Methacrylic Polymers Bearing Side‐Chain Bisazoaromatic Moieties

Synthesis and chiroptical properties of optically active photochromic methacrylic polymers bearing in the side chain the (S)-3-hydroxypyrrolidinyl group conjugated with thetrans-azoaromatic chromophore

Recent developments in colorants for textile applications

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