Polar brilliant red

These two dyes were recently added to the sample card of the acid-and milling-fast Polar dyes of the J. R. Geigy A.G. firm. Since methods for preparing milling-fast azo dyes have not been patented by this firm for several years, it is assumed that the two Polar brilliant red dyes either come under an old disclosure or are not patentable at all. 

Polar brilliant red 3B and B. Polar brilliant red 3B. . . . . Benzo light grey BL. . . . . Brilliant sulfo flavine (LG.) Literature on analysis of dyes. ... 

Monoazo dyes prepared from N-toluenesulfonyl-H acid are, in themselves, not new,io and similarly, the use of aminophenylbenzyl ethers has previously been disclosed. It is to be expected, therefore, that Polar brilliant red 3B could not be patented. One point of scientific interest is the easy splitting of the chloroaminophenylbenzyl ether, merely by boiling with dilute hydrochloric acid, to produce benzyl chloride. ... 

Polar Brilliant Red G Polar Brilliant Red BN Carbolan Yellow R Carbolan Crimson 3B Carbolan Blue B Carbolan Green G... 

Reductive splitting of polar brilliant red 3B (NazSz04) . Reductive splitting of polar brilliant red 3B (SnClz Reductive splitting of benzo light grey BL (SnClz). ... 

A promising aspect of RS for probing surface chemistry involves its ability to evaluate the molecular orientation of monolayer coverages via polarization measurements (146). The orientation of a surface active dye, Suminol Milling Brilliant Red BS, has been studied at a water-carbon tetrachloride interface (147). As the surface area per molecule was reduced the spectra showed a transition which was interpreted as a change from a mixture of orientations to one predominantly perpendicular with respect to the surface. A thorough theoretical analysis of the use of depolarization ratios for the prediction of primary surface orientations of adsorbed molecules has also been reported (148). Similar developments are occurring in IR spectrscopy and a determination of the molecular orientations in a series of polymers has been reported (149). 

Alizarine Light Blue SE C.I. acid blue 43 Alizarine Light Red R C.I. acid red 80 Polar Brilliant Blue GAW C.I. acid blue 127... 

As a class, these pigments are characterized by uncommonly clean and brilliant shades. They provide a number of shades, particularly red and violet ones, that can be duplicated by other organic pigments, but without their brilliance and cleanness. These pigments fail to satisfy more stringent fastness requirements. They are not stable to polar solvents, such as alcohols, ketones, and ethylene glycol. Moreover, they also decompose if exposed to alkali. 

Compound 6-XXVII can be obtained from xylene, toluene or benzene as superb, long, very dark blue-black needles with metallic lustre . A brilliant scarlet form can be obtained from polar solvents such as acetic acid, DMF or DMSO. The black form can be converted to the red form both photophysically and thermally (abruptly at 139-142°C) (Begley et al. 1981). The two structures are shown in Fig. 6.14. In the black form, the molecules form infinite stacks ( in the manner of roof tiles ) in the ac plane with intermolecular contacts of 3.31 A which the authors attribute to charge-transfer interactions. The stacking is absent in the scarlet form, and the molecular conformation is considerably more non-planar, making this pair of structures also conformational polymorphs. No mechanism for the conversion or colour difference has been proposed. 

Hexahydrate, plate-like crystals of pale olive-green color by transmitted light and of a brilliant green to reddish green by reflected light. The crystals polarize light S times as much as tourmaline. Loses its water at 100° and becomes red. Almost insol in water sol in about 1000 parts boiling... 

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