Styryl-type dyes

Mechanisms of voltage sensitivity in the styryl-type dyes depend on their unusual trends in solvent and lipid-induced shifts of absorption and fluorescence... 

Fig. 4 The shortest member of the family of styryl-type voltage sensing dyes. This figure shows the dipole moments computed by INDO/S-CIS [unpublished work by the author] for the ground state and for the excited state following vertical absorption of a photon while remaining planar. The sign of the dipole is seen to reverse...

Crown ether-bound styryl dyes have been studied by Fedorova and her coworkers. The photo chromic properties of the dyes, 91, are based on reversible trans-cis isomerization and [2 + 2]-photocycloaddition. They exhibit a strong preference for formation of complexes with heavy metal ions [72], Due to its specific structure, the betaine-type dye is able to form an anion-capped trans-isomer. Intramolecular coordination in the anion-capped isomer enhances its stability and causes a sharp deceleration of its dark trans-... 

Dyes, polymethine used for dyes having at least one electron donor and one electron acceptor group linked by methine groups or aza analogues aUopolar cyanine, dye bases, complex cyanine, hemicyanine, merocyanine, oxonol, streptocyanine, and styryl. Supersensitization has been reported for these types—18 cites for cyanines, 3 for merocyanine, and 6 for all other polymethine types. 

Uncharged styryl (methine) disperse dyes were originally introduced to provide greenish yellow colours on cellulose acetate fibres. One such dye still in use is Cl Disperse Yellow 31 (6.226), which is made by condensing 4-(N-butyl-N-chloroethylamino)benzaldehyde with ethyl cyanoacetate. Suitable compounds for polyester usually contain the electron-accepting dicyanovinyl group, introduced with the aid of malononitrile. An increased molecular size leads to improved fastness to sublimation, as in the case of Cl Disperse Yellow 99 (6.227). A novel polymethine-type structure of great interest is present in Cl Disperse Blue 354 (6.228), which is claimed to be the most brilliant blue disperse dye currently available [85]. 

This chapter describes the synthesis, properties, and biomedical applications of cyanine and squaraine dyes encapsulated in CDs, CBs, Leigh-type tetralactam macrocycles, aptamers, and micro- or nano-particles. The optical and photochemical properties of supramolecular guest-host nanostructures that are based on intra-and intermolecular complexes of crown-containing styryl dyes with metal cations, and aggregates of carbocyanine dyes are discussed in a separate review [18]. 

The squaraine rotaxane tetracarboxylic acid 15a is soluble in aqueous solution at physiological pH and acts as an excellent fluorescent marker with extremely high photostability, which allows trafficking processes in cells to be monitored in realtime, with constant sample illumination, over many minutes. This type of real-time monitoring cannot be done with other available NIR fluorescent probes, such as the amphiphilic styryl dye KM4-64 and water-soluble dextran-Alexa 647 conjugate, because they are rapidly photobleached. 

Abstract Construction of chemical libraries is a useful approach to the discovery of better fluorescent materials, and several types, such as styryl dyes and cyanine dyes, have been reported. In this chapter, we focus on construction of a library of chemicals having a coumarin skeleton as the core structure. Coumarin and its derivatives are key structures in various bioactive or fluorescent molecules, and their fluorescence properties are dependent on the precise structure, including the positions of substituents. 

Raman spectroscopy has been used in the spectral analysis of several benzothiazolines <77HCA215> and some benzothiazolium photochromic styryl dyes <93SA(A)1055>. Gold (III) chloride complexes of the type of LAuCh (L = thiazole) have been studied by low frequency Raman and infrared spectroscopy <93Mi 306-03>. 

Hagfeldt and coworkers reported the oxidative electropolymerization of styryl-substituted Ru bipyridyl complexes, including 8, designed to act as new sensitizer dyes in Gratzel-type cells. In contrast to other polymers, the 2max of the polymer actually blue-... 

The styrylpyrilium salt derivatives (130) undergo (2 + 2)-cycloaddition to afford the corresponding dimers. The magnetic properties of the radical cations formed from these dimers were compared with those formed from (130). Styryl dyes of the type shown as (131) undergo E-Z isomerization on irradiation at 436 nm. The dyes align themselves in the pattern shown in (132, where the filled blob represents the crown ether complex). These undergo dimerization on irradiation to afford compounds (133), from which the magnesium ions can be removed. 

The molecules of a crown ether styryl dye have been discovered to be arranged in monocrystal in pairs according to "head-to-tail" type so as to make ethylene bonds be situated one above the other. By analogy, the existence of dye molecules in dimeric form could be suggested for the solutions too. Later on we have discovered the susceptibility of crown ether styryl dyes to the formation of dimer in solutions [16]. 

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