Controlling π-π Interactions through Coordination Bond Formation: Assembly of 1-D Chains of acac-Based Coordination Compounds

We present a new approach for the construction of 1-D chains of acac-based copper coordination compounds assembled through pi-pi aromatic interactions. We use 3-(phenylethynyl)pyridine derivatives as ligands that can establish aromatic interactions to intermolecularly bind the coordination compounds. The crystal networks of the free pyridines show that there is no control over aromatic interactions, since different interactions are present. On the other hand, the supramolecular behavior of the coordination compounds is very homogeneous since, in all of the crystal networks, the intended 1-D chains are present. Given the polarization of the aromatic rings due to coordination, reflected in the calculated molecular electrostatic potential maps, we gain control over the pi-pi interaction geometry, promoting a head to tail interaction between the coordinated 3-(phenylethynyl)pyridines. This strategy to constructing 1-D chains is reliable and reproducible; thus, these types of pi-pi aromatic interactions are a useful supramolecular tool to control the molecular assembly in the solid state.

Automated summary

A new approach for constructing 1-D chains of acac-based copper coordination compounds through pi-pi aromatic interactions is presented in this study. By using 3-(phenylethynyl)pyridine derivatives as ligands, control over aromatic interactions in the coordination compounds is achieved, leading to a homogeneous supramolecular behavior and reliable assembly of the intended 1-D chains. The strategy of utilizing pi-pi aromatic interactions proves to be a useful tool for controlling molecular assembly in the solid state.