Life Materials: Nitrogen Compounds and the Reactive Chemistry of a Nitrogen Planet

This chapter explores the chemical foundations of early life from the perspective of Earth as a nitrogen-dominant planet. With molecular nitrogen (N₂) as the atmospheric backbone and traces of primordial hydrogen in the exosphere, the stage was set for a rich interplay of reductive and oxidative nitrogen compounds. Two major nitrogen pathways—NH-type (ammonia/ammonium) and NO-type (nitric oxides)—are examined as dual axes of prebiotic synthesis. The chapter introduces a reactive matrix of elemental combinations (C, N, S, P) × (O, H) to describe primitive bonding patterns leading to biologically relevant molecules such as NH₃, CO₂, and H₂S. Additional atmospheric gases, including CH₄ and SH⁻, contributed to a chemically active environment. Finally, the role of electrostatic discharge (lightning, mineral relaxation) in triggering structural transformations of folded electron-closed surfaces is proposed as a mechanism for early membrane evolution and compartmentalization. Author Tetsuo Konno(今野哲夫)