title: Stabilization of the non-canonical adenine-adeninium base pair by N(7) coordination of Zn(II).
abstract: A new zinc (II) compound with 9-ethyladenine (9-EtA) of formula [Zn(9-EtA-N7)Cl(3)](9-EtAH) has been synthesized and characterized by X-ray diffraction. Its X-structure consists of an Zn(II) anionic complex and 9-ethyladeninium as counteranion. The Zn(II) complex shows a distorted tetrahedral geometry in which three Cl and an 9-EtA coordinates through N(7) position are the ligands. An indirect chelation via intramolecular H-bond between N(6)H and an Cl ligand is present in the complex. The network of [Zn(9-EtA-N7)Cl(3)](9-EtAH) shows interesting features. Thus, self-association of coordinated adenine-adeninium takes place by H-bonding of N(6)-H...N(1) and N(6)-H...N(7), leading to a polymeric ribbon-like 1D supramolecular arrangement. Ab initio calculations have been applied in order to study the stability of the adenine-adeninium interaction due to the coordination of the Zn(II) to the N(7) position and to compare experimental and theoretical structural data.
authors.affiliation: Departamento de Tecnología Industrial, Universidad Alfonso X El Sabio, 28691 Villanueva de la Cañada, Madrid, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Amo-Ochoa
authors.forename: Simone S
authors.initials: SS
authors.lastname: Alexandre
authors.forename: César
authors.initials: C
authors.lastname: Pastor
authors.forename: Félix
authors.initials: F
authors.lastname: Zamora
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism*; D020029:Base Pairing; D008958:Models, Molecular; D009584:Nitrogen / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: C001172:9-ethyladenine; D015032:Zinc; D000225:Adenine; D009584:Nitrogen