Comparison of [Pd2L4][BF4]4cages for binding ofn-octyl glycosides and nitrate (L = isophthalamide or dipicolinamide linked dipyridyl ligand)

Abstract

Two dipyridyl ligands were synthesized, where the pyridyl donor fragments were separated by an isophthalamide (1) or a dipicolinamide moiety (2). Both ligands formed [Pd2(Ligand)4][BF4]4complexes in CD2Cl2containing 5% dmso-d6. It was found that while [Pd2(1)4][BF4]4readily binds ton-octyl glycosides and to nitrate anions, [Pd2(2)4][BF4]4did not. The difference in binding properties could be rationalized based on the reduced flexibility and size of the [Pd2(2)4]2+cage and/or stronger interior binding of a BF4−counter anion.