Toluidine Blue, complexes with

Nakajimo and Matsamura [42] studied the effect of temperature on the induced Cotton effects in toluidine blue complexes with various acidic polysaccharides. They concluded that the signs of the induced Cotton effects do not reflect the entire conformation of the macromolecules local conditions may influence the interaction of the dye and the polymer. Thus affecting the optical activity. 

Quantitation of heparin by photodensitometry may be performed after staining the electrophoretic strips with such dyes as Alcian Blue or Toluidine Blue. Alternatively, the heparin- dye complex may be eluted, for spectrophotometry in solution.68... 

KPVS) and the indicator is usually o-toluidine blue (OTB). It is necessary for kx to be much larger than k2 (which is usually the case for poly electrolytes). If for example a cationic poly electrolyte together with OTB is titrated with KPVS, a polyelectrolyte complex is initially formed until no free polyelectrolyte is left to react with the KPVS. At this point, KPVS starts to react with OTB and a colour shift from light-blue to purplish-red indicates the end point. The titration relies upon the formation of a 1 1 complex, which is generally true provided that the ionic strength is low. 

In a notable paper, Lee et al. [41] examined the dimerization and inclusion complexation equilibria of six phenothiazine dyes, including thionine (TH), azure A (AZA), methylene blue (MB), toluidine blue (TB), new methylene blue (NMB) and 1,9-dimethylmethylene blue (DMMB) (Fig. 2), with CDs (a-, (>-, and y-CDs) in aqueous medium. These phenothiazine dyes presented their structural differences in the position and number of methyl substituents located on the same phenothiazine skeleton. By means of the UV-visible absorption and fluorescence spectra, the authors studied the factors which were responsible for the dimerization of phenothiazine dyes with CDs, in terms of a multiple equilibrium system (Scheme 1). In addition, the authors also determined the JCd values and the corresponding association constants of the monomers (M) and dimers (D) with the CDs [41]. 

Here we encounter again a similar case to that above with gum arabic + toluidine blue since here also under conditions in which the coacervate will go wholly or partially into solution (in the former case by a change of the mixing ratio colloid anion / dye cation, in the present case by the action of the added salt) a large central vacuole is formed. A point of difference is merely that the vacuole does not break through in the present case and thus no pulsation phenomena occur, at least when one chooses the salt concentration so that the complex coacervate just does not go entirely into solution. 

The interaction between three thiazine dyes, namely Azure B, Methylene blue, and Toluidine blue with an anionic polyelectrolyte, and Sodium Carrageenate has been investigated by spectrophotometric method. The polymers induced metachromasy in the dye resulting in the shift of the absorption maximum towards shorter wavelengths. The stoichiometiy and stability of the complexes formed between Thiazine dyes and the polymers are found to be dependent on the stracture of the polymers. The stability of the complexes followed the order AB-NaCar>MB-NaCar>TB-Na-Car. This iirference was further confirmed by reversal of metachromasy by alcohols, urea, surfactants, and electrolytes. The thermodynamic parameters of interaction revealed that binding between Thiazine dyes and the polymers was found to involve both electrostatic and hydrophobic forces. 

Complex formation with Toluidine Blue O has been used to determine the... 

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