5418-32-6Relevant academic research and scientific papers
Interference in Determination of Ammonia with the Hypochlorite-Alkaline Phenol Method of Berthelot
Ngo, T. T.,Phan, A. P. H.,Yam, C. F.,Lenhoff, H. M.
, p. 46 - 49 (1982)
The blue color resulting from the formation of indophenol in the Berthelot method of determining ammonia was supressed by primary and secondary amines, sulfides, thiols, and ascorbic acid, and to lesser extent by tertiary amines.We postulate that nucleophilic additions of amines, thiols, and other nucleophiles to the quinoid intermediates of the Berthelot reaction decrease the formation of indophenol.It is also possible that reducing agents deplete hypochlorite to suboptimal levels.
Preparation and Instability of Nanocrystalline Cuprous Nitride
Reichert, Malinda D.,White, Miles A.,Thompson, Michelle J.,Miller, Gordon J.,Vela, Javier
, p. 6356 - 6362 (2015)
Low-dimensional cuprous nitride (Cu3N) was synthesized by nitridation (ammonolysis) of cuprous oxide (Cu2O) nanocrystals using either ammonia (NH3) or urea (H2NCONH2) as the nitrogen source. The resulting nanocrystalline Cu3N spontaneously decomposes to nanocrystalline CuO in the presence of both water and oxygen from air at room temperature. Ammonia was produced in 60% chemical yield during Cu3N decomposition, as measured using the colorimetric indophenol method. Because Cu3N decomposition requires H2O and produces substoichiometric amounts of NH3, we conclude that this reaction proceeds through a complex stoichiometry that involves the concomitant release of both N2 and NH3. This is a thermodynamically unfavorable outcome, strongly indicating that H2O (and thus NH3 production) facilitate the kinetics of the reaction by lowering the energy barrier for Cu3N decomposition. The three different Cu2O, Cu3N, and CuO nanocrystalline phases were characterized by a combination of optical absorption, powder X-ray diffraction, transmission electron microscopy, and electronic density of states obtained from electronic structure calculations on the bulk solids. The relative ease of interconversion between these interesting and inexpensive materials bears possible implications for catalytic and optoelectronic applications. (Figure Presented).
Investigations of the reactions of monochloramine and dichloramine with selected phenols: Examination of humic acid models and water contaminants
Heasley, Victor L.,Fisher, Audra M.,Herman, Erica E.,Jacobsen, Faith E.,Miller, Evan W.,Ramirez, Ashley M.,Royer, Nicole R.,Whisenand, Josh M.,Zoetewey, David L.,Shellhamer, Dale F.
, p. 5022 - 5029 (2008/04/18)
The phenols are an important area of investigation because they are substituents in the humic acids and are common contaminants in water. The reactivities and orientations of two common phenols (phenol and m-cresol), and some of their chlorinated intermediates with aqueous monochloroamine and dichloroamine were presented. m-Cresol was more reactive than phenol with both chlorinating agents. NH2Cl and NHCl2 showed extensive reactivity toward the phenols, even the partially chlorinated less reactive intermediates would be expected to fully chlorinate the activated positions in phenolic substituents in the humic acids.
Mechanism of the Gibbs reaction. Part 4. Indophenol formation via N- chlorobenzoquinone imine radical anions. The aza-S(RN)2 chain reaction mechanism. Chain initiation with 1,4-benzoquinones and cyanide ion
Pallagi, Istvan,Toro, Andras,Horvath, Gyula
, p. 6530 - 6540 (2007/10/03)
The mechanism of the Gibbs reaction, a colorimetric phenol assay that applies N-chlorobenzoquinone imines 1 in an aqueous basic medium, was investigated. It is concluded that N-chloroimine radical anion 7 generated in a single electron transfer (SET) from the anion of phenol 4 to N-chloroimine 1 can produce indophenol dye 3 in three distinct routes. For more reactive reagent-substrate pairs, a route is proposed that involves a fast combination of the radical pair in the solvent cage and, consequently, the total rate of which exhibits a pH-independent second-order kinetics, as does the preceding SET itself. For less reactive reagents, a route is proposed in which the N- chloroimine radical anion 7 escapes from the solvent cage to initiate a chain reaction, evidenced by its characteristic kinetics. It has been found in the kinetic experiments that during propagation the chlorine of the chain carrier N-chloroimine radical anion 7 is substituted by the anion of 4 in a bimolecular rate-determining step. Therefore, the mechanism of the chain reaction is termed S(RN)2. In the case when the anion of 4 is less active, a competitive reaction along a third route can proceed in which the N-haloimine radical anion 7 yields benzoquinone imine 6 by the elimination of halogenide and the abstraction of an H-atom from the medium. Compound 6 is also known to give indophenol 3 with a second-order but pH-dependent rate that is considerably faster than the rate in the first route. On the basis of the different kinetic characteristics outlined above a clear distinction can be made among these three pathways. In this paper, evidence is also presented for the initiating SET. Furthermore, it is of high importance that the N- haloimine radical anion 7 can also be generated from reagent 1 using external electron donors and, independently of its origin, it can be spin trapped with 2,2,6,6-tetramethylpiperidine-N-oxyl.
