Phosphorus Chemistry in the Earth's Upper Atmosphere

Abstract

Phosphorus is a key element in biomolecules (e.g., RNA, DNA, phospholipids, and ATP/ADP) and therefore plays important roles in replication, information transfer, and metabolism (Maciá, 2005). Although the dominant form of inorganic P at the Earth's surface is orthophosphate (PO 4 3− , oxidation state +5), phosphate salts have low water solubility and reactivity, which severely limits their bio-availability. Therefore, a major question concerning the development of early life on Earth was the availability of prebiotic P in its reduced forms, phosphides (P − , oxidation state −1), phosphites (HPO 3 2− , oxidation state +3) or hypophosphites (H 2 PO 2 − , oxidation state +3), which are more biologically active than the fully oxidized phosphate. Phosphorus is thought to have limited ocean primary productivity over geological timescales, and the P cycle may have constrained the slow oxygenation of the Earth's surface during the first 3.5 billion years (Lyons et al., 2014). In support of this hypothesis of P bio-limitation, Reinhard et al. ( 2017) have shown recently that, until around 800 million years ago, the P in shallow marine environments was significantly lower than the Redfield ratio (Redfield, 1958).Because phosphorus is a siderophile element, the P that was present when the Earth formed should be sequestered in the molten core; hence, extraterrestrial P was probably the major source of prebiotic phosphorus at the planet's surface (Pasek, 2008). Previous studies have focused on the direct delivery of P to the surface in meteorites, where metal phosphides (in particular the mineral schreibersite, (FeNi) 3 P) were then processed into bioavailable forms of P through aqueous-phase chemistry (Gibard et al., 2019;Pasek, 2008). A very recent study has shown that cloud-ground lightning strikes reduce phosphate in meteorites, and estimated that lightning strikes on early Earth might have formed 10-1,000 kg of phosphide and 100-10,000 kg of phosphite and hypophosphite annually (Hess et al., 2021).In the present paper, we consider the ablation of P from interplanetary dust particles (IDPs) entering the Earth's atmosphere and its subsequent atmospheric chemistry. This potential source of reduced P does not appear to have been investigated previously. Most IDPs have a mass ranging from 10 −3 to 100 μg (radius 2-200 μm), and a substantial fraction of the IDP mass ablates due to aerobraking at heights between 70 and 110 km (Carrillo-Sánchez, Gómez-Martín, et al., 2020). We recently performed a laboratory study

Sources of Nitrogen-, Sulfur-, and Phosphorus-Containing Feedstocks for Prebiotic Chemistry in the Planetary Environment

“…When entering the planetary atmosphere, interplanetary dust particles can undergo ablation and lose mass; the processing of vaporized P in the atmosphere could be a source of reduced phosphorus compounds [ 224 ]. The effect of ablation in liberating phosphorus and the subsequent phosphorus chemistry was investigated by Plane et al [ 225 ], who found phosphorus can be delivered in the form of meteoric smoke particles and that the speciation of phosphorus after ablation depends on the oxygen fugacity of the atmosphere. From this source, phosphorus mainly takes the form of PO 2 in the upper planetary atmosphere, which can then undergo further reactions to form PO and other species [ 226 ].…”

Spectroscopic Identification and Photochemistry of Astrochemically Relevant Phosphorus-bearing Molecules [O, C, N, P] and [2O, C, N, P]

“…According to the theoretical study on the mechanism for the interconversion between PO and PN, the depletion of PO by N atom (PO + N → PN + O) occurs spontaneously, whereas the collision between PN and O atom contains a small barrier of 6-10 kJ mol −1 (Souza et al 2021). It has been proposed that both PO and PN are key prebiotic compounds, particularly, PO is the building block of biomolecules for the backbone of ribonucleic acids DNA and RNA (de la Concepción et al 2021;Plane et al 2021), and PN acts as a modification site for the molecular switch in the process of protein arginine phosphorylation (pArg; Elsholz et al 2012). Chemically, phosphorus mononitride (PN) is much more reactive than the nitrogen congener N 2 and it polymerizes very rapidly at ambient conditions.…”

Investigation of the Proton-Bound Dimer of Dihydrogen Phosphate and Formate Using Infrared Spectroscopy in Helium Droplets

“…In inorganic chemistry, orthophosphoric acid (H 3 PO 4 ) has been shown to play a fundamental role in prebiotic chemistry, 1−3 as well as in complex atmospheric processes. 4,5 Further, due to its high proton conductivity, it is widely used as a proton carrier in the development of ionic-liquids membrane fuel cells. 6−9 Of particular importance are the many biochemical processes where phosphate-containing biomolecules take part, and several comprehensive reviews on the biophysics and biochemistry of phosphorus have been published.…”