18983-82-9

Usage

Uses

Used in Medical Diagnostics:
Carbon dioxide (18O2) is used as a tracer gas in medical diagnostics for monitoring respiratory function and assessing the efficiency of gas exchange in the lungs. Its unique isotope signature allows for accurate tracking and measurement of gas movement within the respiratory system.
Used in Research:
In research, carbon dioxide (18O2) serves as a valuable tool for studying various biological and chemical processes. Its distinct isotope signature enables researchers to track and analyze the incorporation of oxygen-18 into different molecules, providing insights into metabolic pathways, enzymatic reactions, and other biochemical processes.
Used in Industrial Applications:
Carbon dioxide (18O2) is utilized in various industrial applications, including the production of carbonated beverages, where it is used as a leavening agent to create the desired fizz. It is also employed in the manufacture of chemicals, such as urea and methanol, and in the enhancement of oil recovery processes, where it is injected into oil reservoirs to increase the extraction of crude oil.
Used in Environmental Monitoring:
Carbon dioxide (18O2) plays a crucial role in environmental monitoring and climate change research. Its unique isotope signature allows scientists to study the sources, sinks, and fluxes of carbon dioxide in the atmosphere, helping to understand the dynamics of the global carbon cycle and the impact of human activities on climate change.
Used in Food Industry:
In the food industry, carbon dioxide (18O2) is used as a preservative and an ingredient in the production of carbonated beverages, providing the characteristic fizz and enhancing the taste and texture of the products. Its controlled release and solubility properties make it an ideal choice for maintaining the quality and freshness of various food products.

Upstream product

• 124-38-9 carbon dioxide 
• 32767-18-3 oxygen-18 
• 51060-05-0 fulminic acid 
• 1632-99-1 ethane-d6 
• 15917-79-0 H₂⁽¹⁵⁾N⁽¹⁸⁾O 
• 10102-44-0 Nitrogen dioxide 
• 2537-69-1 carbon dioxide 
• 554-13-2 lithium carbonate 
• 34557-54-5 methane 
• 201230-82-2 carbon monoxide 
• 80937-33-3 oxygen 
• 14797-71-8 ¹⁸O-labeled water 
• 4685-14-7 Paraquat 
• 244156-36-3 NC⁽¹⁸⁾O 

Relevant academic research and scientific papers

Product channels in the 193-nm photodissociation of HCNO (fulminic acid)

IR diode laser spectroscopy was used to detect the products of HCNO (fulminic acid) photolysis at 193 nm. Six product channels are energetically possible at this photolysis wavelength: O + HCN, H + NCO/CNO, CN + OH, CO + NH, NO + CH and HNCO. In some experiments, isotopically labeled 15N18O, C2D6 or C6H12 reagents were included into the photolysis mixture in order to suppress and/or redirect possible secondary reactions. HCN, OC18O, 15N15NO, CO, DCN and HNCO molecules were detected upon laser photolysis of HCNO/reagents/buffer gas mixtures. Analysis of the yields of product molecules leads to the following photolysis quantum yields: φ1a (O + HCN) = 0.38 ± 0.04, φ1b (H + (NCO)) = 0.07 ± 0.02, φ1c (CN + OH) = 0.24 ± 0.03, φ1d (CO + NH(a1Δ)) 1e (HNCO) = 0.02 ± 0.01 and φ1f (CH + NO) = 0.21 ± 0.1, respectively.

Geometrical Structure of the Gold–Iron(III) Oxide Interfacial Perimeter for CO Oxidation

The geometrical structure of the Au-Fe2O3 interfacial perimeter, which is generally considered as the active sites for low-temperature oxidation of CO, was examined. It was found that the activity of the Au/Fe2O3 catalysts not only depends on the number of the gold atoms at the interfacial perimeter but also strongly depends on the geometrical structure of these gold atoms, which is determined by the size of the gold particle. Aberration-corrected scanning transmission electron microscopy images unambiguously suggested that the gold particles, transformed from a two-dimensional flat shape to a well-faceted truncated octahedron when the size slightly enlarged from 2.2 to 3.5 nm. Such a size-induced shape evolution altered the chemical bonding environments of the gold atoms at the interfacial perimeters and consequently their catalytic activity. For Au particles with a mean size of 2.2 nm, the interfacial perimeter gold atoms possessed a higher degree of unsaturated coordination environment while for Au particles with a mean size of 3.5 nm the perimeter gold atoms mainly followed the atomic arrangements of Au {111} and {100} facets. Kinetic study, with respect to the reaction rate and the turnover frequency on the interfacial perimeter gold atom, found that the low-coordinated perimeter gold atoms were intrinsically more active for CO oxidation. 18O isotopic titration and Infrared spectroscopy experiments verified that CO oxidation at room temperature occurred at the Au-Fe2O3 interfacial perimeter, involving the participation of the lattice oxygen of Fe2O3 for activating O2 and the gold atoms for CO adsorption and activation.

New Strategy for in Vitro Determination of Carbonic Anhydrase Activity from Analysis of Oxygen-18 Isotopes of CO2

The oxygen-18 isotopic (18O) composition in CO2 provides an important insight into the variation of rate in isotopic fractionation reaction regulated by carbonic anydrase (CA) metalloenzyme. This work aims to employ an 18O-isotope ratio-based analytical method for quantitative estimation of CA activity in erythrocytes for clinical testing purposes. Here, a new method has been developed that contains the measurements of 18O/16O isotope ratios during oxygen-18 isotopic exchange between 12C16O16O and H218O of an in vitro biochemical reaction controlled by erythrocytes CA and estimation of enzymatic activity of CA from the isotopic composition of CO2. We studied the enrichments of 18O-isotope of CO2 with increments of CA activities during isotopic fractionation reaction. To check the influence of subject-specific body temperature, pH, H218O, and cellular produced CO2 on this reaction, we performed the in vitro experiments in closed containers with variations of those parameters. Finally, we mimicked the exchange reaction at 5% [CO2], 5‰ [H2 18O], pH of 7.4, and temperature of 37 °C to create the physiological environment equivalent to that of the human body and monitored the exchange kinetics with variations of CA activities, and subsequently, we derived the quantitative relation between the 18O-isotope of CO2 and CA activity in erythrocytes. This assay may be applicable for rapid and simple quantification of carbonic anhydrase activity which is very important to prevent the carbonic-anhydrase-associated disorders in human.

Electron-mediated co oxidation on the TiO2(110) surface during electronic excitation

The role of electrons and holes in the electronically excited oxidation of adsorbed CO on TiO2(110) has been investigated by tuning the surface electron and hole availability by the adsorption of Cl2 or O 2. The presence o

A Structural Mimic of Carbonic Anhydrase in a Metal-Organic Framework

Metal-organic frameworks (MOFs) have exciting potential for biomimetic studies of enzymes, yet construction of high-fidelity models at the metal nodes is challenging. Nonetheless, biomimetic MOFs have significant advantages, such as increased stability and ease of separation, over their enzymatic and homogeneous counterparts, making them particularly attractive for industrial applications. Here, we demonstrate biomimetic behavior of Zn hydroxide moieties inside a MOF with structural and reactivity characteristics of carbonic anhydrase. Similar to the biological system, the MOF binds CO2 by an insertion mechanism into the Zn–OH bond, leading to significant adsorption of CO2 (3.41 mmol/g). In reactivity mimicking that of the enzyme, the material also catalyzes the oxygen isotope exchange between water and carbon dioxide. Overall, these results provide the strongest evidence yet of metal nodes in MOFs bearing high structural fidelity to enzymatic active sites. The nodes of metal-organic frameworks are attractive sites for mimicking metalloenzymes, primarily through their site isolation and similar ligand fields. In this article, the metal-organic framework MFU-4l is shown to mimic the active site of carbonic anhydrase with high structural fidelity and reactivity. The material adsorbs high quantities of carbon dioxide at low pressures and mimics critical features of carbonic anhydrase, such as isotopic exchange of oxygen atoms from water and carbon dioxide. Mimicking metalloenzymes at the node of a metal-organic framework (MOF) has the potential to impart enzyme-like catalytic activity within a heterogeneous material. Carbonic anhydrase, one of nature's fastest enzymes, catalyzes the hydrolysis of carbon dioxide into bicarbonate and protons. Notably, carbonic anhydrase mimics have been proposed as potential catalysts for carbon capture and sequestration from the environment. Here, we demonstrate that the metal node of MFU-4l, a MOF featuring a metal node with a N3ZnX coordination environment, can be functionalized to give a mimic of carbonic anhydrase. This work describes a well-defined example of a metal node within a MOF with high structural fidelity to an enzyme active site. It has potential applicability to applications such as CO2 capture and sequestration and also important gas separations involving CO2.

Gas-Phase Reactions Involving Hot 18O(3P) Atoms and Formaldehyde

We report an investigation of the low-pressure gas-phase reactions involving hot 18O(3P) atoms with translational energies in excess of 1 eV and formaldehyde.Using mass spectrometry, (18)O incorporation in C(16)O(18)O and HC(18)O products was observed.These results strongly suggested that the carbonyl bond addition was an important reaction at these energies.

The effect of water on the heterogeneously catalyzed selective oxidation of acrolein: An isotope study

The effect of water on the selective gas phase oxidation of acrolein to acrylic acid on a Mo/V/W mixed oxide catalyst was studied by performing steady-state isotopic transient kinetic analysis experiments with H 218O. Experiments were performed in the temperature range of 90-345C at ambient pressure. It could be shown that acrolein exchanges its carbonylic oxygen with oxygen from water even at low temperatures (200C), the oxygen atoms of the water molecules incorporate into all oxidation products such as acrylic acid, carbon monoxide, and carbon dioxide.

Fourier transform microwave spectra of the very weakly bound He-CO2 dimer

Spectra of pure rotational transitions of the very weakly bound He-CO2 van der Waals complex were investigated using a pulsed molecular beam Fourier Transform microwave spectrometer. The complex exhibits very large amplitude internal vibrational motions and the rotational transitions were, as a consequence, difficult to locate and to assign. Eight isotopomers, namely He-CO2, He-13CO2, He-OC18O, He-O13C18O, He-18OC18O, He-18O13C18O, He-OC17O, and He-O13C17O, were studied in order to establish the assignments. The hyperfine structures due to the quadrupolar 17O nucleus were resolved and analyzed in the two 17O containing isotopomers. The observed nuclear quadrupole hyperfine structures not only provide further confirmation for the assignment but also give new information about the angular anisotropy of the He-CO2 interaction potential.

Anion-Receptor Mediated Oxidation of Carbon Monoxide to Carbonate by Peroxide Dianion

The reactivity of peroxide dianion O22- has been scarcely explored in organic media due to the lack of soluble sources of this reduced oxygen species. We now report the finding that the encapsulated peroxide cryptate, [O2?mBDCA-5t-H6]2- (1), reacts with carbon monoxide in organic solvents at 40 °C to cleanly form an encapsulated carbonate. Characterization of the resulting hexacarboxamide carbonate cryptate by single crystal X-ray diffraction reveals that carbonate dianion forms nine complementary hydrogen bonds with the hexacarboxamide cryptand, [CO3?mBDCA-5t-H6]2- (2), a conclusion that is supported by spectroscopic data. Labeling studies and 17O solid-state NMR data confirm that two-thirds of the oxygen atoms in the encapsulated carbonate derive from peroxide dianion, while the carbon is derived from CO. Further evidence for the formation of a carbonate cryptate was obtained by three methods of independent synthesis: treatment of (i) free cryptand with K2CO3; (ii) monodeprotonated cryptand with PPN[HCO3]; and (iii) free cryptand with TBA[OH] and atmospheric CO2. This work demonstrates CO oxidation mediated by a hydrogen-bonding anion receptor, constituting an alternative to transition-metal catalysis.

Confined Pt11+ Water Clusters in a MOF Catalyze the Low-Temperature Water–Gas Shift Reaction with both CO2 Oxygen Atoms Coming from Water

The synthesis and reactivity of single metal atoms in a low-valence state bound to just water, rather than to organic ligands or surfaces, is a major experimental challenge. Herein, we show a gram-scale wet synthesis of Pt11+ stabilized in a confined space by a crystallographically well-defined first water sphere, and with a second coordination sphere linked to a metal–organic framework (MOF) through electrostatic and H-bonding interactions. The role of the water cluster is not only isolating and stabilizing the Pt atoms, but also regulating the charge of the metal and the adsorption of reactants. This is shown for the low-temperature water–gas shift reaction (WGSR: CO + H2O → CO2 + H2), where both metal coordinated and H-bonded water molecules trigger a double water attack mechanism to CO and give CO2 with both oxygen atoms coming from water. The stabilized Pt1+ single sites allow performing the WGSR at temperatures as low as 50 °C.