Phthalimides: Supramolecular interactions in crystals, hypersensitive solution 1H-NMR dynamics and energy transfer to europium(III) and terbium(III) states

Abstract

Detailed crystal structures and 1H-NMR characteristics of some alkylaminephthalimides, including dendritic polyphthalimides, are reported. These investigations were undertaken in order to obtain a better understanding of the relationship between solid-state supramolecular interactions, their persistence in solution and associated dynamics of magnetically hypersensitive phthalimide aromatic AA'BB'-AA'XX' proton NMR resonances. Some alkylamine phthalimides feature folded molecular geometries, which we attribute to n-π interactions among proximal amine-phthalimide sites; those alkylamine- phthalimides that have no possibility for such interactions feature fully extended phthalimide functionalities. Accordingly, alkylamine phthalimide compounds with folded solid-state geometries feature solvent and temperature dependent hypersensitive AA'BB'-AA'XX' 1H-NMR line profiles, which we attribute to the n-π interactions. Luminescence of Eu(3+)((5)D0) and Tb(3+)((5)D4) states show well defined metal ion environments in their complexes with dendritic phthalimides, as well as relatively weak phthalimide- lanthanide(III) interactions.