Condensed-phase reactions of O₃ with NH₃ and NH₂OH

Abstract

The reactions of O3 with NH3 and NH2OH were studied in the condensed phase. A yellow ozonide was formed immediately upon the addition of O3 to the NH2OH solid maintained at −190 °C, but the yellow–orange ozonide seen in the NH3 case was not formed until the system was warmed to −170 °C. These ozonides could be reconverted to reactants by photolysis with near ultraviolet light or by heating to −90 °C (NH3+O3−) or −115 °C (NH2OH+O3−).Upon warming the NH3–O3 system to −130 °C, NH4NO3•3NH3 appeared. It started to deamminate at about −105 °C to give NH4NO3. In the NH3–O3 system a second species, tentatively identified as NH2O+HO2−, was also formed at −170 °C. It began to decompose with the evolution of O2 at about −10 °C.In the NH2OH–O3 system, HNO3 was also seen immediately upon addition of O3 to NH2OH. It appeared as NH2OH•HNO3, a hydrogen-bonded complex with NH2OH. At about −100 °C, NH2OH started to anneal and the NH2OH•HNO3 bands grew rapidly and converted to NH3OH+NO3−.There was no evidence of NH2OH as an intermediate in the NH3–O3 system, but since NH2OH reacted so readily with O3, this possibility could not be ruled out. These ozonolysis reactions may be represented as[Formula: see text]and[Formula: see text]

Thermal Oxidation Reaction between NH3 and O3: Low-temperature Formation of an NH4+ -bearing Salt

“…The absence of NO -2 is also consistent with aqueous work (Equation ( 8)), where Singer & Zilli (1975) note the absence of detectable nitrite in solution despite a O 3 /NO -3 ratio of 4. Interestingly, we also observe a feature near 800 cm −1 above 90 K, which has been previously attributed to ozonide in mixtures of NH 3 and O 3 (Herman & Giguère 1965;Huston et al 1983b). While it is possible that this is ozonide, it may also be a weaker band of nitrate, as its appearance and increase correlate well with the stronger nitrate doublet absorptions at higher wavenumbers.…”

“…Unlike the studies mentioned above, which examined this chemical system at or near room temperature, Huston et al (1983b) found that a reaction between NH 3 and O 3 also occurs readily at cryogenic temperatures in the solid phase. This reaction produced NH 4 NO 3 in the presence of excess NH 3 through the intermediate ammonia ozonide ( + NH 3 O -3 ), which was identified based on an IR absorption band at 800 cm −1 and a yellow color change:…”

“…Keller & Halford (1949), Smith et al (1991) + NH 4 1506 ν 4 Miller & Wilkins (1952), Knop & Giguère (1959), Loeffler & Hudson (2015) + NH 4 + NH 3 2058 L Corset et al (1968), Lundeen & Tobias (1975), Huston et al (L Bertie & Devlin (1984), Moore et al (2007) 800 ν L Moore et al (2007) -O 3 800 ? Herman & Giguère(1965),Huston et al (1983b)…”

Experimental model of ammonia elimination by ozone in the air

“…Th e reaction kinetics NH 3 -O 3 producing NH 4 NO 3 were studied in a water solution (Hoigné, Bader 1978) in the gas stage (Olszyna, Heicklen 1972) as well as in the condensation stage (Huston et al 1983). If ozone and ammonia react in the gas stage at room temperature, the majority of the products are NH 4 NO 3 , O 2 and H 2 O, produced according to the noted Eq.…”