LAUSR

Abstract Three copper complexes with an N-methylated cryptand, LTEA, bearing a tris(2-aminoethylamine moiety have been synthesized and compared. Two copper(II)-chloride complexes, [LTEACuCl](SbF6)(MeOH) and [LTEACuCl2](MeCN) were characterized in solution and solid state by UV/Vis spectroscopy and X-ray crystallography. Both had square-based geometries with C1-symmetry and no encapsulation of the chloride ion. A copper(II)-fluoride complex, in which the ligand is protonated, [LTEAHCuF](BF4)2(MeCN)0.5, adopted C3-symmetry with complete encapsulation of the coordination sphere as characterized by UV/Vis, EPR and X-ray crystallography. Reactivity of the complexes with H2O2/Et3N was explored using UV/Vis and CSI-MS. Only the fluoride complex was found to form a Cu(II)-hydroperoxo intermediate.