THE ROLE OF METAL PHOSPHITES: ABIOTIC SYNTHESIS, CHARACTERIZATION, AND REACTIVITY UNDER EARLY EARTH CONDITIONS**

Phosphorus is a fundamental element in life. According to the geological record, phosphate minerals were abundant on the early Earth; however, they are highly insoluble. Therefore, they were unlikely to be the direct source of phosphorus for life on the early Earth. In comparison, metal phosphites are significantly more soluble and contain phosphorus in an intermediate oxidation state (+3), making them more reactive than phosphates because they can undergo redox as well as acid-base chemistry. Metal phosphites could have been formed by several plausible formation pathways under prebiotic conditions including corrosion of meteoric minerals and iron redox geochemistry in the early Earth’s oceans. Our experiments address the research question, What are the prebiotic species formed when metal phosphites undergo abiotic aqueous chemistry under early Earth conditions? Thus far, we\u27ve synthesized and characterized four of the most plausible metal phosphites (calcium, magnesium, iron (II), and iron (III) phosphite), using infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), phosphorus nuclear magnetic resonance (P-NMR). To calculate percent yields for future reactivity experiments, we have determined the solubility of the metal phosphites using a combination of inductively coupled plasma - optical emission spectroscopy (ICP-OES) and P-NMR. Future experiments will measure the reactivity of the metal phosphites with glycerol and propanol using NMR. Comparing the percent yields for the reactivity measurements with other prebiotically plausible pathways to the formation of organophosphates may reveal that metal phosphites were key intermediates on the early Earth