title: Base pair analogs in the gas phase.
abstract: A rotationally resolved electronic spectrum of the gas-phase dimer 2-aminopyridine.2-pyridone, an analog of the adenine.thymine base pair, has been observed and assigned, leading to precise measurements of its moments of inertia and preliminary determinations of its structure. A Watson-Crick configuration results, with N...H-N and N-H...O hydrogen bond lengths of 2.898 and 2.810 A, respectively. The two bases are found not to be coplanar; a dihedral angle of 6.1 degrees between the base planes is also estimated from the measured moments of inertia. Possible chemical and biological implications of these results are discussed.
authors: Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA.
authors: Joseph R
authors: JR
authors: Roscioli
authors: David W
authors: DW
authors: Pratt
mesh_terms: D000631:Aminopyridines / Q000737:chemistry; D020029:Base Pairing; D004247:DNA / Q000737:chemistry*; D005740:Gases; D006860:Hydrogen Bonding; D066298:In Vitro Techniques; D008958:Models, Molecular; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D011728:Pyridones / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D000631:Aminopyridines; D005740:Gases; D011728:Pyridones; C017679:2-hydroxypyridine; D004247:DNA; C032439:alpha-aminopyridine