Abstract 4-(2-Pyridylazo)resorcinol (PAR) sodium salt reacts with aromatic aldehydes and malononitrile in aqueous ethanol to form 2-amino-4-aryl-5-hydroxy-6-(2-pyridylazo)-4 H -chromene-3-carbonitriles.

Fluorescence resonance energy transfer in complexes of semiconductor CdSe/ZnS quantum dots with molecules of heterocyclic azo dyes, 1-(2-pyridylazo)-2-naphthol and 4-(2-pyridylazo) resorcinol, formed at high quantum dot concentration in the polymer pore track membranes were studied by steady-state and transient PL spectroscopy. The effect of interaction between the complexes and free quantum do...

Extraction of 2-(2-pyridylazo)-1-naphthol-4-sulfonate anion with solvated hydroxonium ion was carried out using 14 kinds of alcohols and 1-octanol/octane mixed solvents as a solvent at 25 degrees C. Alcohols are 1-pentanol, 1-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, 1-octanol, 2-octanol, 3-octanol, 1-nonanol, 2-nonanol, 3-nonanol, 5-nonanol and 1-decanol. Among them, 1-octanol w...

Of two sensitive complexometric reagents for the colorimetry of serum zinc that we investigated, one, 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP), was found to be a potentially useful compound for trace-metal determinations. It has a high molar absorptivity (120 000 L mol-1 cm-1) but is not convenient to use because it is not very soluble in water. The other reagent, a related pyri...

The solvent extraction of trivalent lanthanoids (La, Nd, Eu, Ho, and Lu) with mixtures of the chelating extractant 1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedione (thenoyltrifluoro-acetone, HTTA) or 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-on (HP) and 4-(2-pyridylazo)-resorcin (PAR, S) in CHCl3 was studied. It was found that in the presence of 4-(2-pyridylazo)-resorcin the lanthanoids were extra...

The acidity constants of 4-(2-pyridylazo)resorcinol (PAR, Scheme 1) in binary mixtures of methanol–water at 25 ◦C and an ionic strength of 0.1 M have been determined spectrophotometrically. DATa ANalysis (DATAN) program applied for determination of acidity constants. As percent of methanol increases in solvent mixtures the pKa constants also increased. There is linear relationship between acidi...

1-(2-Pyridylazo)-2-naphthol has been used for extraction concentration of palladium, copper, cobalt and nickel from aqueous solutions and subsequent separation of the chelates obtained, by means of high-pressure liquid chromatography. A technique for determining microamounts of palladium in aqueous solutions in the presence of 100-fold ratio of copper and 80-fold ratio of cobalt has been develo...

The full spectrum technique in the fourier domain was studied for simultaneous determination of Cu(II), Pb(II) and Cd(II) with 4-(2-pyridylazo) resorcinol (PAR). A program called SPGRFSQ. was designed to perform the calculations. Seven error functions were calculated for deducing the number of factors. Data reduction was performed using principal component analysis (PCA) algorithm. Experimental...

A mixture of Ti(IV) and 4-(2-pyridylazo) resorcinol was found to be useful in the spectrophotometric determination of trace amounts of hydrogen peroxide. The absorbance of the complex formed at 508 nm was proportional to the concentration ofhydrogen peroxide added. The reagent was applied to the assay ofglucose through coupling with glucose oxidase which produces HP2' This method of glucose det...

A simple approach to sensor development based on encapsulating a probe molecule in a cellulose support followed by regeneration from an ionic liquid solution is demonstrated here by the codissolution of cellulose and 1-(2-pyridylazo)-2-naphthol in 1-butyl-3-methylimidazolium chloride followed by regeneration with water to form strips which exhibit a proportionate (1 : 1) response to Hg(II) in a...