Extraction-Chromogenic Systems for Gallium(III) Based on Azo Dyes and Xylometazoline Hydrochloride

First Synthesis of 2-Amino-5-hydroxy-4H-chromene-3-carbonitriles from 4-(2-Pyridylazo)resorcinol

“…4-(2-Pyridylazo)resorcinol (PAR, 4), available in the form of sodium salt monohydrate, has long been actively used in analytical chemistry as a non-selective tridentate complexing agent for the extraction and concentration of heavy metal ions, as a metallochromic indicator for complexometric titration, reagent for the photometric determination of analytes (for reviews, see [19][20][21][22][23]). In recent years, PAR has been actively used to create optical sensors and test materials for the determination and extraction of heavy metals [24][25][26][27], spectrophotometric analysis of transition metals in catalysts [28], extraction of Rh 3+ [29], Ga 3+ [30], Ir 4+ [31], and Co 2+ ions [32], obtaining charge-transfer complexes with aromatic nitro compounds [33], etc. However, as far as we know, 4-(2-pyridylazo)resorcinol has not yet been used as a reagent for fine organic synthesis.…”

Extraction of Gallium(III) with a New Azo Dye in The Presence or Absence of Xylometazoline Hydrochloride

“…[13][14][15][16][17][18] Cationic ion-association reagents have been used in our laboratory to improve the hydrophobicity and extraction characteristics of such chelates: tetrazolium salts, [19,20] nitron [21] and xylometazoline hydrochloride (XMH). [22] Extraction systems containing both Ga(III) and 6-hexyl-4-(2-thiazolylazo)resorcinol (HTAR) have not been studied so far. The aim of this paper is to investigate the complex formation between Ga(III) and HTAR in water-chloroform medium in the presence or absence of XMH.…”

“…Its cation (XMH + ) has a dispersed positive charge [24] and tends to form ion-pairs with various complex anions. [22,23,[25][26][27]…”