COLORIMETRIC determination of vitamin A has frequently been based upon the Carr-Price reaction, namely the production of a blue colour when vitamin A is added to a saturated solution of antimony trichloride in chloroform, which shows two absorption maxima at 606 m,u and at 572 m,u, respectively. This reaction has the following drawbacks: (1) the blue colour is not specific for vitamin A, being ...

The structures of 1,2,4-triazolium chloride (C2H4N3)Cl and its derivative with antimony trichloride (C2H4N3)2[SbCl5] ÿ (C2H4N3)Cl containing unsubstituted 1,2,4-triazolium cations were determined. (C2H4N3)Cl crystallizes in the monoclinic system, space group P21/n with the unit cell dimensions at 86 K: a = 9.425(2), b = 8.557(2), c = 11.158(2) Å, þ = 95.87(3); V = 895.2(3) Å3,Z= 8,dc = 1.566,dm...

The discovery of melamine by Justus von Liebig was fundamental for the development several fields chemistry. vast majority compounds with or derivatives appear as adducts. Herein, we focus on novel containing anionic species, namely melaminates. For this purpose, analyze reaction SbCl3 differential scanning calorimetry (DSC). whole study includes synthesis and characterization three antimony th...

It is now well established that vision in dim light is due to the photochemical decomposition of “visual purple,” a pigment present in the rods of the retina (1). Visual purple is believed to be a conjugated protein in which vitamin A or one of its derivatives is a prosthetic group (2). As might be expected, the spectral sensitivity curve of the eye parallels the absorption spectrum of visual p...