78. Nitryl chloride. Part I. Its preparation and the properties of its solutions in some organic solvents

Abstract

Nitryl chloride, NO,Cl, was prepared by Dachlaucher's method as a pale yellow liquid, b. p. -14~3"~ m. p. -141" f 2". Gaseous nitryl chloride decomposes a t room temperature very slowly. The alkaline hydrolysis of nitryl chloride to hypochlorite and nitrite was confirmed. The nature of nitryl chloride in various organic solvents was studied as a preliminary to examining its reactions with organic compounds. Its solutions in less polar solvents are colourless, and those in polar solvents are yellow, the latter owing their colour to nitrosyl chloride and chlorine, formed by the hydrolysis of nitryl chloride by traces of moisture in these solvents. It also reacts with hydrogen chloride.

Formation of Nitrating and Chlorinating Species by Reaction of Nitrite with Hypochlorous Acid

“…To confirm the identity of the reaction product, the purified product was diluted in methanol, and the absorbance spectrum was immediately measured. The observed absorbance spectrum of synthetic Cl-NO 2 showed a series of characteristic absorption maxima between 300 and 400 nm, similar to that reported previously (43).…”

“…However, a divergence in the characteristics of the reaction mechanisms between NO 2 ϩ and the reactive nitrating species formed by the reaction of NO 2 Ϫ with HOCl is evident in their reactions with MPA, the O-methylated derivative of HPA, There is evidence suggesting that the reaction of Cl-NO 2 with alkenes and aromatic compounds involves homolytic processes yielding free radical intermediates (42), probably involving both Cl ⅐ and ⅐ NO 2 . Collis et al (43) have found that Cl-NO 2 decomposes at room temperature by homolysis to form Cl 2 and ⅐ NO 2 as shown in Reaction 3, whereby these spontaneous decomposition products may be responsible, at least in part, for the chlorinating and nitrating behavior of Cl-NO 2 in our experiments. We suggest that phenolic nitration mediated by the NO 2 Ϫ /HOCl reaction involves ⅐ NO 2 .…”

“…NO 2 -Tyr, Cl-Tyr, and dityrosine formation in the samples were determined by HPLC following acid hydrolysis as described below. (42,43) with slight modification. Sulfuric acid (61 g) was added dropwise to vigorously stirred nitric acid (50 g) at 0°C in a 500-ml three-necked round bottom flask equipped with a dropping funnel.…”

“…Data points are expressed as means of three separate experiments. (43). The addition of methanol to the reaction mixture of NO 2 Ϫ and HOCl caused a hypsochromic shift (20 nm) in the absorption spectrum (Fig.…”

Kinetics and mechanism of the oxidation of hydroxylamine by aqueous chlorine

“…Fates for the proposed transient intermediates, C1NHOH and Cl2NOH, other than reaction with Cl2 (eqs 13 and 14) include their dissociation reactions (eqs 27 and 28). Nitrosyl hydride *ld C1NHOH -* Cl" + HNO + H+ (27) ku Cl2NOH -Cl" + CIÑO + H+ (28) (HNO) is reported37 to dimerize very rapidly to give nitrous oxide (eq 29). The equilibrium formation of nitrosyl chloride (C1NO) 2HNO -N20 + H20 (29) has been reported38 in high concentrations of hydrochloric acid.…”