title: Metal-Molecule Interactions To Produce Hydrogen:  What Do They Have in Common?
abstract: The main purpose of this work is to study metal-molecule interactions that can lead to the production of molecular hydrogen. Two systems were chosen for this analysis:  yttrium atom and clusters interacting with the simple electron donor ammonia (NH3) and copper atoms and ions with imidazole. For yttrium with ammonia as well as for copper with imidazole there is a charge-transfer process from the metal to the molecule that promotes the dissociation of the hydrogen atoms.
authors.affiliation: Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, C. U., P.O. Box 70-360, Coyoacán 04510, México, D. F. México.
authors.forename: Job
authors.initials: J
authors.lastname: Valdespino-Saenz
authors.affiliation: Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, C. U., P.O. Box 70-360, Coyoacán 04510, México, D. F. México.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Guevara-García
authors.affiliation: Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, C. U., P.O. Box 70-360, Coyoacán 04510, México, D. F. México.
authors.forename: Marco-Vinicio
authors.initials: MV
authors.lastname: Vázquez
authors.affiliation: Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, C. U., P.O. Box 70-360, Coyoacán 04510, México, D. F. México.
authors.forename: Ana
authors.initials: A
authors.lastname: Martínez