Synthesis, crystal structures and properties of 1,1′-ferrocenyldi(bisamide) derivatives generated by the double Ugi four-component reaction

Abstract

In this article, six novel 1,1′-ferrocenyldi(bisamide) derivatives 1–6 were facilely synthesized in good yields via the double Ugi four-component reaction. Their chemical structures were fully characterized by IR, NMR and HR-MS analyses. The crystal structural evaluation demonstrates that 3 and 5 adopt a linear centrosymmetric conformation, while 6 gives a v-shape conformer in the solid state. They all assemble into 2-D networks and create diverse supramolecular motifs involving 6- to 26-membered rings by combining versatile N−H⋅⋅⋅O, C−H⋅⋅⋅O, and C−H⋅⋅⋅π interactions. The crystal packing driving forces were further confirmed with the Hirshfeld surface analysis. Moreover, their electrochemical recognition properties were initially assessed. In these 1,1′-ferrocenyldi(bisamide) conjugates, variant substituents at the bisamide chain greatly affect not only the supramolecular assemble but also the electrochemical recognition properties.