Chiral Basket Resorc[4]arenes are well known chiral solvating agents that can induce enantiodiscrimination towards aminoacids, peptides and nucleosides. We synthesized both enantiomer of some basket resorc[4]arenes capable of forming stable diasteromeric host-guest complexes with some nucleosides like cytidine and cytarabine. The reactivity and the structures of the complexes were investigated in gas-phase (ESI-IRMPD, ESI-FT-ICR) and in solution (DOSY, ROESY). Different "in" and "out" structures were found both in solution and in gas-phase, moreover the results were supported by theoretical calculations