Characterization of HCN-derived thermal polymer: Implications for chemical evolution
Por:
Villafañe-Barajas S.A., Ruiz-Bermejo, Marta, Rayo-Pizarroso, Pedro, Colin-Garcia, Maria
Publicada:
1 ene 2020
Resumen:
Hydrogen cyanide (HCN)-derived polymers have been recognized as sources of relevant organic molecules in prebiotic chemistry and material sciences. However, there are considerable gaps in the knowledge regarding the polymeric nature, the physicochemical properties, and the chemical pathways along polymer synthesis. HCN might have played an important role in prebiotic hydrothermal environments; however, only few experiments use cyanide species considering hydrothermal conditions. In this work, we synthesized an HCN-derived thermal polymer simulating an alkaline hydrothermal environment (i.e., HCN (l) 0.15 M, 50 h, 100 °C, pH approximately 10) and characterized its chemical structure, thermal behavior, and the hydrolysis effect. Elemental analysis and infrared spectroscopy suggest an important oxidation degree. The thermal behavior indicates that the polymer is more stable compared to other HCN-derived polymers. The mass spectrometric thermal analysis showed the gradual release of several volatile compounds along different thermal steps. The results suggest a complicate macrostructure formed by amide and hydroxyl groups, which are joined to the main reticular chain with conjugated bonds (C=O, N=O, -O-C=N). The hydrolysis treatment showed the pH conditions for the releasing of organics. The study of the synthesis of HCN-derived thermal polymers under feasible primitive hydrothermal conditions is relevant for considering hydrothermal vents as niches of chemical evolution on early Earth. © 2020 by the authors.
Filiaciones:
Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de México, Ciudad Universitaria, Cd. Mx, 04510, Mexico
Centro de Astrobiología (CSIC-INTA), Dpto. Evolución Molecular, Ctra. Torrejón-Ajalvir, km 4, Torrejon de Ardoz, Madrid, 28850, Spain
Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Cd. Mx, 04510, Mexico
Univ Nacl Autonoma Mexico, Posgrad Ciencias Tierra, Ciudad Univ, Cd Mx 04510, Mexico
Ctr Astrobiol CSIC INTA, Dept Evoluc Mol, Ctra Torrejon Ajalvir,Km 4, Madrid 28850, Spain
Univ Nacl Autonoma Mexico, Inst Geol, Ciudad Univ, Cd Mx 04510, Mexico
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