title: Alanine water complexes.
abstract: Two complexes of alanine with water, alanine-(H2O)n (n = 1,2), have been generated by laser ablation of the amino acid in a supersonic jet containing water vapor and characterized using Fourier transform microwave spectroscopy. In the observed complexes, water molecules bind to the carboxylic group of alanine acting as both proton donors and acceptors. In alanine-H2O, the water molecule establishes two intermolecular hydrogen bonds forming a six-membered cycle, while in alanine-(H2O)2 the two water molecules establish three hydrogen bonds forming an eight-membered ring. In both complexes, the amino acid moiety is in its neutral form and shows the conformation observed to be the most stable for the bare molecule. The microsolvation study of alanine-(H2O)n (n = 1,2) can be taken as a first step toward understanding bulk properties at a microscopic level.
authors.affiliation: Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, Universidad de Valladolid , 47005 Valladolid, Spain.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Vaquero
authors.forename: M Eugenia
authors.initials: ME
authors.lastname: Sanz
authors.forename: Isabel
authors.initials: I
authors.lastname: Peña
authors.forename: Santiago
authors.initials: S
authors.lastname: Mata
authors.forename: Carlos
authors.initials: C
authors.lastname: Cabezas
authors.forename: Juan C
authors.initials: JC
authors.lastname: López
authors.forename: José L
authors.initials: JL
authors.lastname: Alonso
mesh_terms: D000409:Alanine / Q000737:chemistry*; D006860:Hydrogen Bonding; D008872:Microwaves; D013057:Spectrum Analysis; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D000409:Alanine