A Cation-Directed Switch of Intermolecular Spin−Spin Interaction of Guanosine Derivatives Functionalized with Open-Shell Units
作者:Carla Graziano、Stefano Masiero、Silvia Pieraccini、Marco Lucarini、Gian Piero Spada
DOI:10.1021/ol8003832
日期:2008.5.1
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