1,8-Naphthalimide Synthon in Silver Coordination Chemistry: Control of Supramolecular Arrangement

The reaction of N-[2,2-bis(pyrazolyl)ethane]-1,8-naphthalimide (L1) and N-[2,2-bis(3,5-dimethylpyrazolyl)ethane]-1,8-naphthalimide (L2) with silver tetrafluoroborate produced two new compounds, formulated on the basis of elemental figures and ESI/MS+ experiments as [Ag(L1)2](BF4) and [Ag(L2)2](BF4), respectively. Crystallization of these two compounds resulted in the formation of two pseudopolymorphs in each case; the structures of all four have been determined by X-ray crystallography. The common feature of all four structures is the directional π−π stacking of the naphthalimide groups, with the dipole vectors oriented at 180° antiparallel. The crystal packing is also influenced by several other noncovalent interactions, such as the pyrazolyl embrace, C−H···π interactions, and weak C−H···O hydrogen bonds.