Russian and canadian chemists have found that minerals zhemchuzhnikova and Stepanovic found in the 1960s in the coal mines of Yakutia are the natural analogue of synthetic metal-organic frameworks, porous polymers with unique properties.
This discovery completely reverses our notions of what these are popular in chemistry materials are pure synthetics, a human invention. Their discovery suggests that nature may exist even larger reserves of the IOC. If the pioneers zhemchuzhnikova could determine its structure, science would leap forward 30 years, said Friscic Tomislav (Tomislav Friscic) from McGill University (Canada).
The story of this discovery originates with the fact that Frisco and his colleague at the University, he has Guccis (Igor Huskic), studied one of the directories of minerals, produced by the canadian geological organization. In it, they came across a description of two unusual organic minerals Stepanovic and zhemchuzhnikova opened by Soviet geologists in the 1940-ies and 1960-ies in one of the coal mines in Siberia.
They are thin translucent veins or crystals of green glass, which were found as inclusions in the coal seams and other sedimentary rocks soaked in natural acetic acid, which happens very rarely, and that can only be found in the permafrost.
The crystal structure stepanovica and zhemchuzhnikova was unknown, however, the Soviet scientists have determined their formula – they consist of sodium, iron, magnesium, aluminum, organic acids, oxalate and water — and describe how x-rays are reflected from its surface.
Their composition and the data on x-ray crystallography prompted Huskies and Friscia the idea that they are very similar to the so-called metal-organic frameworks — the complex polymer materials, similar in structure to a honeycomb with very high porosity and strength. Today the IOC is used to create a filter capable of trapping carbon dioxide or hydrogen and retain huge amounts of these gases.
To check and confirm this idea has Huskys and Frisco turned for help to two Russian geologists – Igor Pekova from MSU M. V. Lomonosov and Sergey Krivovichev from Saint-Petersburg state University. They have helped canadian researchers to find the source of these minerals – mines and Tullah Chay-Tumus in Yakutia, to zhemchuzhnikova samples, to determine the structure of the crystal and create its synthetic analogs.
As it turned out, zhemchuzhnikova and Stepanovic really belong to the metal-organic frameworks – they are composed of many hydrocarbon threads, braided in a kind snowflake and the honeycomb, which are metal ions combined with water molecules. These ions, unfortunately, as they note, the data interfere with natural minerals to absorb CO2 and hydrogen, which cannot be used for industrial purposes.
According to scientists, synthetic deposits of these minerals in Yakutia are unique – other places on Earth where there are large quantities of acetic acid in the conditions of permafrost, probably not. However, the canadian researchers plan to continue the search for natural versions of the IOC in an attempt to find more interesting connections than those who did not create nature, and chemists.