Preparation and characterization of gas-phase carbonic acid and its monomethyl ester
Until fairly recently, scientists were convinced that carbonic acid (H2CO3) does not exist as a stable molecule. In the journal Angewandte Chemie, German researchers have now introduced a simple pyrolytic method for the production of gas-phase carbonic acid that allowed the spectroscopic characterization of gas-phase carbonic acid and its monomethyl ester.
Carbonic acid is a physiologically important molecule. For example, it helps maintain a constant pH value for blood and is an important intermediate in the formation of the carbon dioxide we exhale. It is also likely to play an essential role in CO2 sequestration technologies. There is also much evidence for the presence of solid carbonic acid in extraterrestrial ice, including on the surface of Mars, and in interstellar regions.
A team led by Peter R. Schreiner at the University of Giessen has now developed a novel and broadly applicable method for the production of gas-phase carbonic acid. Their technique is based on the pyrolysis of a readily available precursor molecule (Di-tert-butyl dicarbonate) in the gas phase.
The resulting carbonic acid is trapped in an extremely cold, noble gas matrix. By starting with a different precursor molecule, the researchers were able to extend their new pyrolysis technique to obtain gas-phase carbonic acid monomethyl ester for the first time.
Trapped in their icy matrix, the carbonic acid and carbonic acid monomethyl ester could be subjected to exhaustive infrared spectroscopic studies for the first time. Comparison of the data with theoretically calculated values showed excellent agreement.
The results of these experiments bring new insight into a matter of controversy concerning carbonic acid: are there really, as was proposed by several teams of researchers some time ago, two different crystalline forms of carbonic acid, the alpha and beta forms? Schreiner and his co-workers say this is not the case.
Their spectroscopic data agree perfectly with the vapor phase above the theoretical beta form, but not the vapor phase of the solid thought to be the alpha form of carbonic acid. However, the spectra of the carbonic acid monomethyl ester correspond beautifully to this supposed alpha-carbonic acid.
Says Schreiner: “It is clear that the molecule previously thought to be the alpha form of carbonic acid is actually the carbonic acid monomethyl ester.” This conclusion is in accord with the method used to prepare the “alpha form”, which uses methanol as a solvent under acidic conditions that favor an esterification reaction between carbonic acid and methanol.
“Our results shed new light on the gas-phase chemistry of carbonic acid,” says Schreiner. “They will be highly useful for the identification of carbonic acid in the environment and the atmosphere, as well as in astrophysical research.”
About the Author
Dr. Peter R. Schreiner is a Professor of Organic Chemistry at the University of Gießen. He and his research group are interested in understanding organic chemistry at its most fundamental level, including the preparation of previously unknown molecules, the use of hydrogen-bonding organocatalysts, and the development of the chemistry of nanodiamonds. He is an elected member of the German National Academy of Sciences (Leopoldina) and is the recipient of the Dirac Medal.
Author: Peter R. Schreiner, Justus-Liebig-Universität Giessen (Germany), http://www.uni-giessen.de/cms/fbz/fb08/Inst/organische-chemie/agschreiner
Title: Gas-Phase Preparation of Carbonic Acid and Its Monomethyl Ester
Angewandte Chemie International Edition Permalink to the original article: http://dx.doi.org/10.1002/anie.201406969 – Please use in your news piece to make sure altmetric.com picks it up and a link to your piece is shown on the journal's website.
Peter R. Schreiner | Angewandte Chemie
Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex
New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
22.06.2018 | Materials Sciences
22.06.2018 | Earth Sciences
22.06.2018 | Life Sciences