title: A cation-directed switch of intermolecular spin-spin interaction of guanosine derivatives functionalized with open-shell units.
abstract: The guanosine derivative 1 functionalized with the persistent radical unit 4-carbonyl-2,2,6,6-tetramethylpiperidin-1-oxyl in solution has no particular intermolecular spin-spin interactions; however, in the presence of potassium ions this compound can form a D4-symmetric octameric assembly [1(8)K]+ in which the nitroxyl moieties show a weak electron spin-spin exchange interaction. Since the relative geometry of the radicals is the outcome of K+-directed self-assembly, the spin-spin interaction can be suppressed by removing the alkaline ion.
authors.affiliation: Alma Mater Studiorum, Università di Bologna, Dipartimento di Chimica Organica A. Mangini, Bologna, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Graziano
authors.forename: Stefano
authors.initials: S
authors.lastname: Masiero
authors.forename: Silvia
authors.initials: S
authors.lastname: Pieraccini
authors.forename: Marco
authors.initials: M
authors.lastname: Lucarini
authors.forename: Gian Piero
authors.initials: GP
authors.lastname: Spada