Defects on a pyrite(100) surface produce chemical evolution of glycine under inert conditions : experimental and theoretical approaches

Acknowledgements This work has been supported by the MINECO project ESP2017-89053. The Instituto Nacional de Tecnica Aeroespacial supported the work performed at CAB. EER is thankful to Javier Martin-Torres, Alfonso Hernandez-Laguna and C. M. Pradier for their support and suggestions. This Project has been partially funded by the Spanish State Research Agency (AEI) Project No. MDM-2017-0737 Unidad de Excelencia ‘‘Marıa de Maeztu’’-Centro de Astrobiologıa (CSIC-INTA).Peer reviewedPublisher PD

Investigación mecano-cuántica de las estructuras cristalinas, propiedades espectroscópicas y reactividad de filosilicatos 2:1 dioctaédricos

Tesis Univ. Granada. Departamento de Química Orgánica. Leída el 21 de diciembre de 200

Growth of Self-Assembling Tubular Structures of Magnesium Oxy/Hydroxide and Silicate Related With Seafloor Hydrothermal Systems Driven by Serpentinization

Abstract Tubular structures self‐assemble from precipitating magnesium salts under the chemical garden chemobrionic growth process. Two experimental procedures, the dissolution of magnesium salt pellets and the injection of magnesium salt solutions into silicate solutions, were explored to reproduce in the laboratory the geochemical conditions under which similar structures may form from mineral‐rich fluids at some seafloor hydrothermal vents driven by serpentinization. X‐ray diffraction and Raman microspectroscopy applied to the materials formed indicated the presence of layers of magnesium silicate and magnesium oxide/hydroxide. Quantum mechanical calculations based on density functional theory were performed on models of hydrated magnesium silicate surfaces and related minerals to explain the Raman spectroscopy results. We examine the precipitate morphology, chemical structure, and crystal or mineral structure in our experiments and how these change with the reaction conditions. This is a fascinating example in geochemistry of a self‐organizing nonequilibrium process that creates complex structures

Molecular structure and ammonia gas adsorption capacity of a Cu(II)-1,10-phenanthroline complex intercalated in montmorillonite by DFT simulations

A hydrated complex of 1,10-phenanthroline with Cu cation was intercalated in the interlayer space of montmorillonite. This intercalation occurs initially by through a cation exchange mechanism in which the charge of the complex cation compensates the excess of the negative charge of the interlayer, then, once the cation exchange capacity (CEC) value has been reached, by direct adsorption of the sulfate salt of this complex (i.e. the cation together with its sulfate counterion). This material has showed interesting entrapping properties of gaseous phases and a peculiar chemical reactivity. However, the complete characterization and explanation of the formation of these materials is difficult with only experimental techniques. Hence, we used computational methods at atomic level to know how are the molecular structure of these complexes and their adsorption capacity of ammonia inside the interlayer confined space of montmorillonite for a better understanding of the experimental behaviour. First Principles calculations were performed based on Density Functional Theory (DFT). The intercalation of the phenanthroline-Cu(II) complex inside the nanoconfined interlayer of montmorillonite is energetically favourable in the relative proportion observed experimentally, being a cation exchange process. The further adsorption of the sulfate salt of the phenanthroline-Cu complex is also energetically possible. The adsorption of ammonia molecules in these montmorillonite-phenanthroline-Cu complexes was also favourable according with experimental behaviour.Authors would like to acknowledge the contribution of the European COST Action CA17120 supported by the EU Framework Programme Horizon 2020, and are thankful to the University of Modena and Reggio Emilia for the Visiting Professor programme, to the Computational Centre CIRC of University of Granada, The Computational Center of CSIC in Madrid, and CINECA of Bologna for the high performance computing service, and Spanish projects FIS2016-77692-C2-2-P and PCIN-2017-098 for financial support