title: Prebiotic-Like Condensations of Cyanamide and Glyoxal: Revisiting Intractable Biotars.
abstract: We report a detailed investigation into the nature of products that are generated by the reactions of cyanamide and glyoxal, two small molecules of astrochemical and prebiotic significance, under different experimental conditions. The experimental data suggest that the formation of oligomeric structures is related in part to the formation of insoluble tholins in the presence of oxygen-containing molecules. Although oligomerization proceeds well in water, product isolation turned out to be impractical. Instead, solid precipitates were obtained easily in acetone. Crude mixtures have been thoroughly scrutinized by spectroscopic methods, in particular NMR and mass spectroscopy (ESI mode), which are all consistent with the generation of a few functional groups that are embedded into regular chains of five- and six-membered rings, thereby pointing to a supramolecular organization. Three different models of cross-condensation and chain growth are suggested. These synthetic explorations provide further insights into the formation of complex organic matter in interstellar scenarios and extraterrestrial bodies that might have played a pivotal role in chemical evolution.
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias-UEX, IACYS-Unidad de Química Verde y Desarrollo Sostenible, 06006, Badajoz, Spain. nlavador@gmail.com.
authors.forename: Nieves
authors.identifier: http://orcid.org/0000-0002-5553-1541
authors.initials: N
authors.lastname: Lavado
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias-UEX, IACYS-Unidad de Química Verde y Desarrollo Sostenible, 06006, Badajoz, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Escamilla
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias-UEX, IACYS-Unidad de Química Verde y Desarrollo Sostenible, 06006, Badajoz, Spain.
authors.forename: Martín
authors.initials: M
authors.lastname: Ávalos
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias-UEX, IACYS-Unidad de Química Verde y Desarrollo Sostenible, 06006, Badajoz, Spain. reyes@unex.es.
authors.forename: Reyes
authors.identifier: http://orcid.org/0000-0003-4853-0484
authors.initials: R
authors.lastname: Babiano
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias-UEX, IACYS-Unidad de Química Verde y Desarrollo Sostenible, 06006, Badajoz, Spain.
authors.forename: Pedro
authors.identifier: http://orcid.org/0000-0002-2608-3604
authors.initials: P
authors.lastname: Cintas
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias-UEX, IACYS-Unidad de Química Verde y Desarrollo Sostenible, 06006, Badajoz, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Jiménez
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Facultad de Ciencias-UEX, IACYS-Unidad de Química Verde y Desarrollo Sostenible, 06006, Badajoz, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Palacios
keywords: cyanamide; glyoxal; heterocycles; oligomerization; prebiotic chemistry