New life of "old" molecules. A new approach to the development of organic reactions involving calcium carbide was proposed in the joint paper of the ZIOC RAS and St. Petersburg State University

One of the main challenges for humanity today is the development of a new generation of industrial processes that make it possible to obtain the most important organic substances and materials with a carbon-neutral approach. A classic method for the construction of the carbon framework in organic synthesis is usage of simple building blocks such as HC≡CH, HC≡C^- and C≡C^2-. To obtain the latter two, one needs to use an acetylide source. A number of metal acetylenides are particularly promising for this role in the context of green chemistry concept and the development of a carbon-neutral approach. Calcium carbide is the most accessible raw material-source of the acetylenide fragment, which is currently used for the synthesis of a significant amount of organic compounds. However, CaC₂ is insoluble in organic solvents, which significantly reduces its reactivity in the liquid phase.

In their recent work, researchers from the Zelinsky Institute and St. Petersburg State University simulated on an atomic scale the processes occurring during the interaction of calcium carbide with water and dimethyl sulfoxide. It was shown that the nature of the proton source played a key role in the activation of carbide in reactions in solution. Water is excellent for this role due to its lower acidity in DMSO compared to acetylene. Thus, the dynamics of CaC₂ protolysis occurring at the solid-liquid interface is probably of paramount importance for further understanding of CaC₂ activation.

Source:

Mikhail V. Polynski, Mariia D. Sapova and Valentine P. Ananikov Understanding the solubilization of Ca acetylide with a new computational model for ionic pairs Chem. Sci., 2020, accepted manuscript. DOI: 10.1039/D0SC04752J.

Born-Oppenheimer molecular dynamics of an acetylenide intermediate dissolved in dimethyl sulfoxide: