Atmospheric chemistry, sources and sinks of carbon suboxide, C<sub>3</sub>O<sub>2</sub>

Abstract

Abstract. Carbon suboxide, O = C = C = C = O, has been detected in ambient air samples and has the potential to be a noxious pollutant and oxidant precursor; however, its lifetime and fate in the atmosphere are largely unknown. In this work, we collect an extensive set of studies on the atmospheric chemistry of C 3 O 2 . Rate coefficients for the reactions of C 3 O 2 with OH radicals and ozone were determined as k OH = (2.6 ± 0.5) × 10 −12 cm 3 molecule −1 s −1 at 295 K (independent of pressure between ∼ 25 and 1000 mbar) and k O 3 < 1.5 × 10 −21 cm 3 molecule −1 s −1 at 295 K. A theoretical study on the mechanisms of these reactions indicates that the sole products are CO and CO 2 , as observed experimentally. The UV absorption spectrum and the interaction of C 3 O 2 with water (Henry's law solubility and hydrolysis rate constant) were also investigated, enabling its photodissociation lifetime and hydrolysis rates, respectively, to be assessed.The role of C 3 O 2 in the atmosphere was examined using in situ measurements, an analysis of the atmospheric sources and sinks and simulation with the EMAC atmospheric chemistry-general circulation model. The results indicate sub-pptv levels at the Earth's surface, up to about 10 pptv in regions with relatively strong sources, e.g. influenced by biomass burning, and a mean lifetime of ∼ 3.2 days. These predictions carry considerable uncertainty, as more measurement data are needed to determine ambient concentrations and constrain the source strengths.

Assessment of aldehyde contributions to PTR-MS m/z 69.07 in indoor air measurements

“…10 Early iterations of PTR-MS were equipped with a quadrupole detector allowing only 1 amu mass resolution, so that any species generating signals between 69 and 70 amu were potential interferents with the accurate quantification of isoprene. Prior outside air studies noted the potential of cyclopentene, furan, 2-methyl-3-buten-ol 11 and even the minor constituent carbon suboxide (C 3 O 2 12 ) to contribute to m / z 69. More recent versions of the PTR-MS have been equipped with a time of flight mass spectrometer capable of higher mass resolution allowing identification of the exact molecular formula; they are therefore less prone to interference through fragmentation.…”

Proton-Transfer-Reaction Mass Spectrometry: Applications in Atmospheric Sciences

“…A study in a ponderosa pine forest demonstrated that NO + chemistry allows selective measurements of isoprene and MBO 187. In addition to C 5 H 8 H + and C 4 H 4 OH + , a small peak (C 3 O 2 H + , m/z 68.997) attributed to carbon suboxide is observed at m/z 69 in PTR-TOF mass spectra 188. m/z 71.…”

Theoretical Study of the Temperature- and Pressure-Dependent Rate Constants for Nine Reactions between COn (n = 0–4), Om (m = 1–3), C2O, and C3O2 during the Radiolysis of Carbon Dioxide

“…28 Meanwhile, regarding another substance generated during radiolysis, C 3 O 2 , a report has studied its atmospheric chemical properties. 29 The research involved investigating its spectral characteristics at infrared and ultraviolet wavelengths to assess its greenhouse effect and to determine its atmospheric photolysis rate constants. and two CO, making the photolysis of C 3 O 2 a direct source of C atoms, 31 which can in turn participate in other reactions.…”

“…Furthermore, while the existence of CO 4 is challenging to capture under current experimental conditions in the reaction of CO + O 3 to generate CO 4 , the theoretical investigation of the lowest singlet potential energy surface of this molecule has been explored . Meanwhile, regarding another substance generated during radiolysis, C 3 O 2 , a report has studied its atmospheric chemical properties . The research involved investigating its spectral characteristics at infrared and ultraviolet wavelengths to assess its greenhouse effect and to determine its atmospheric photolysis rate constants.…”