ESI-MS detection of very weak π-Stacking interactions in the mixed-ligand sandwich complexes formed by substituted benzo-crown ethers and metal cations

Abstract The stability of the mixed-ligand complex formed by amino-benzo-15-crown-5 and nitro-benzo-15-crown-5, with a metal cation, [$ NH_{2} $B15C5+$ NO_{2} $B15C5+K]+, was found to be enhanced by π-stacking interactions. This conclusion was deduced by comparison of the abundance of the mixed-liga...
Ausführliche Beschreibung

Abstract The stability of the mixed-ligand complex formed by amino-benzo-15-crown-5 and nitro-benzo-15-crown-5, with a metal cation, [$ NH_{2} $B15C5+$ NO_{2} $B15C5+K]+, was found to be enhanced by π-stacking interactions. This conclusion was deduced by comparison of the abundance of the mixed-ligand complex with the abundances of homo-ligand complexes ([($ NH_{2} $B15C5)2+K]+, [($ NO_{2} $B15C5)2+K]+), as well as with those of 1:1 complexes ([$ NH_{2} $B15C5+K]+, [$ NO_{2} $B15C5+K]+). Some solvents and some metal cations with large radii were also found to prevent the existence of π-stacking interactions. Ausführliche Beschreibung