Nitrosonium Nitrate. Isolation at 79°—205°K and Infrared Spectra of the Polymorphic Compound

Abstract

Nitrosonium nitrate, NO+NO3−, a red solid, has been studied spectroscopically at temperatures ranging up to 205°K. Reproducible shifts of fundamental frequencies upon warming suggest two crystalline transformations between 79° and 205°K. The γ-, β-, and α-phase have been observed under nonequilibrium conditions in the following temperature ranges, respectively: 79°—185°, 167°—187°, 167°—205°K. The fundamental frequencies of the constituent ions in the γ, β, and α phase are: ν(NO)+: 2215, 2271, 2251 cm−1; ν3: 1364, 1324, 1328 cm−1; ν2: 819, 827, 812 cm−1; ν4: 716, 716, 711 cm−1.

The heterogeneous hydrolysis of NO2 in laboratory systems and in outdoor and indoor atmospheres: An integrated mechanism

“…2 is uptake of gaseous N 2 O 4 on the surface and its isomerization to surface asymmetric ONONO 2 . This isomerization is known to occur in solid matrices at low temperatures or high pressures, on ice and in solution, 101,[135][136][137][138][139][140][141][142][143][144][145][146][147][148][149][150] (although one study 151 observed only the symmetric form of N 2 O 4 on ice films). Koel and coworkers [148][149][150]152 proposed that this isomerization occurs via the free O-H groups on amorphous ice, and it is possible that a similar process occurs in the thin films studied here.…”

Intermediates Involved in the Oxidation of Nitrogen Monoxide: Photochemistry of the cis‐N2O2⋅O2 complex and of sym‐N2O4 in Solid Ne Matrices

“…A huge number of reports have already appeared on N 2 O 4 species, and we are not inclined to give a comprehensive overview. N 2 O 4 derivatives were investigated in the liquid [6][7][8] and solid state; [9][10][11][12] in liquid rare gases; [13,14] organic solvents; [6,15,16] in various solid matrices such as Ne, [17] Ar, [18][19][20][21] N 2 [22] and O 2 ; [19,20] and adsorbed on amorphous and crystalline water-ice films. [23,24] These studies have shown that two NO 2 radicals in principle may combine to various N 2 O 4 species.…”

“…Table 1 lists those species that may be envisioned and includes the ionic nitrosonium nitrate, NO + NO 3 À . [15,24,[43][44][45][46][47] Those species that are proposed to be involved in the oxidation of NO by O 2 are marked by a tick. Although many of these species may exist only as short-lived intermediates in the gas phase, if they are prevented from reacting to form more stable species, as for example, by isolation in rare-gas matrices, they can in principle be detected and characterised by using spectroscopic techniques.…”

“…Despite the large body of experimental and computational studies devoted to weakly bound N 2 O 4 species, our knowl- edge particularly about nitroso nitrate remained scarce. Nitroso nitrate, ONONO 2 , was proposed to play an important part in the condensed state chemistry of NO 2 , such as the self-ionisation of dinitrogen tetraoxide leading to nitrosonium nitrate NO + NO 3 À , [15,24,43,44,46,47] and its hydrolysis to nitrous (HONO) and nitric acid (HONO 2 ). [24,63] But only limited work has been reported on the thermochemistry of this less stable N 2 O 4 isomer, [7] and even the dissociation enthalpy of trans-ONONO 2 into 2 NO 2 has, to our knowledge, not been measured experimentally.…”

“…[15,24,[43][44][45] Indeed, in former matrix-isolation studies both cis-and trans-ONONO 2 (denoted as D' and D, respectively) were tentatively assigned. [20] The predicted spectra for trans- (Table 2) and cis-like ONONO 2 (Table S2 in the Supporting Information) reveal substantial differences.…”