|Name||Mr. Arthur Omran|
|Organization or Institution||FSU Chemistry and Biochemistry|
Heterogeneous Catalysis of Prebiotic Chemistry by Calcium Carbonate, Barium Carbonate and Iron Sulfide Chemical Gardens.
Arthur Omran and Oliver Steinbock
Florida State University Department of Chemistry and Biochemistry
Hydrothermal environments could be the setting for where life originated. Hydrothermal vent chimneys such as black and white smokers can be simulated in the lab using pump injected chemical garden tubes. The hydrothermal vent chimneys are examples of chemical gardens themselves. To simulate white smoker hydrothermal vents, we have synthesized calcium carbonate and barium carbonate chemical garden tubes, by injecting calcium chloride and barium chloride respectively, into sodium silicate solution. To simulate black smoker hydrothermal vents, we have synthesized iron (II) sulfide chemical garden tubes, by injecting iron (II) chloride into sodium silicate solution containing sodium sulfide. We have characterized these precipitation products spectroscopically and with x-ray diffraction. We then expose these tubes to hydrothermal conditions and added formaldehyde. We found that these tubes act as a heterogeneous catalyst for the formose reaction and produce various sugars associated with the reaction. Furthermore, we found that at lower starting pH values for our system the calcium and barium tubes act as a catalyst for the Cannizzaro reaction, producing formic acid and methanol; additionally, the iron sulfide tubes catalyze the production of glyoxylic acid. We verified the products of these reactions using 1H NMR. Moreover, the presence of organic species in the system does not inhibit the precipitation formation of the chemical garden tubes. Finally, we demonstrate that the carbonate tubes evolve a bicarbonate buffer. We believe that synthesis and transport in a hydrothermal environment could form, and subsequently protect via buffering, biomonomers setting the stage for further chemical evolution.