Scheibe aggregate formation of cyanine dyes in monolayers
TL;DR: In this article, a 1:1 mixture of a stearyl substituted monomethin cyanine dye and a long chain hydrocarbon was shown to form a closely packed monolayer with the chromophores arranged like a brick stone work.
About: This article is published in Chemical Physics Letters.The article was published on 1970-08-01. It has received 135 citations till now. The article focuses on the topics: Cyanine & Monolayer.
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TL;DR: This Review provides an overview on the J-aggregates of a broad variety of dyes created by using supramolecular construction principles, and discusses their optical and photophysical properties as well as their potential applications.
Abstract: J-aggregates are of significant interest for organic materials conceived by supramolecular approaches. Their discovery in the 1930s represents one of the most important milestones in dye chemistry as well as the germination of supramolecular chemistry. The intriguing optical properties of J-aggregates (in particular, very narrow red-shifted absorption bands with respect to those of the monomer and their ability to delocalize and migrate excitons) as well as their prospect for applications have motivated scientists to become involved in this field, and numerous contributions have been published. This Review provides an overview on the J-aggregates of a broad variety of dyes (including cyanines, porphyrins, phthalocyanines, and perylene bisimides) created by using supramolecular construction principles, and discusses their optical and photophysical properties as well as their potential applications. Thus, this Review is intended to be of interest to the supramolecular, photochemistry, and materials science communities.
1,913 citations
952 citations
TL;DR: In this article, a water-soluble porphyrin, 5,10,15,20,tetra(4,sulfophenyl)porphyrin (H2TPPS44−), formed in acidified aqueous solutions, exhibits sharp and intense absorption bands at 491 and 707 nm.
Abstract: J aggregate of a water‐soluble porphyrin, 5,10,15,20‐tetra(4‐sulfophenyl)porphyrin (H2TPPS44−), formed in acidified aqueous solutions, exhibits sharp and intense absorption bands at 491 and 707 nm. These characteristic transitions, J bands, are of linear oscillators polarized in the long axis of rodlike aggregate. The molecules in the aggregate stack so as to lift the degeneracy of the porphyrin planar oscillator excited states. Measurements of flow‐induced linear dichroism, circular dichroism, magnetic circular dichroism, as well as polarized fluorescence excitation spectra provide evidence not only of linear oscillator character of the intense J band at 491 nm, but also of presence of another diffuse absorption band around at 420 nm polarized in the short axis of the aggregate, which is the counterpart of the 491 nm band of porphyrin Soret origin. Extrinsic circular dichroism is induced upon addition of L‐tartaric acid or by mechanical swirling flow in the period of aggregate growth. Resonance Raman spe...
446 citations
TL;DR: In this article, the formation of dye dimers and higher aggregates in solution as a function of dye structure and environmental variables are considered, together with silver halide composition and crystal habit.
304 citations
TL;DR: In this article, an energy transfer takes place from a sensitizer (S) layer to an acceptor (A) layer and results in fluorescence of A. S and A may be cyanine dyes.
Abstract: Systems of monomolecular layers can form functional units having properties not exhibited by the individual layers. On UV irradiation, for example, an energy transfer takes place from a sensitizer (S) layer to an acceptor (A) layer and results in fluorescence of A. S and A may be cyanine dyes. Monomolecular layers can be manipulated in many ways and combined to construct novel systems; the energy transfer method can be used to establish whether the desired structure has in fact been produced. The monolayer assembling technique can also be used for the investigation of the deactivation of excited molecules; an interesting example is the spectral sensitization of the photographic process.
242 citations
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TL;DR: In this article, the structures of aggregates of dye molecules are investigated on the basis of quantum-mechanical calculations, and a brick stone work arrangement is obtained instead of the ladder or staircase arrangement hitherto assumed.
295 citations