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

Abstract

We present a new approach for the construction of 1-D chains of acac-based copper coordination compounds assembled through π−π 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 π−π 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 π−π aromatic interactions are a useful supramolecular tool to control the molecular assembly in the solid state.

Double Hook Perylene Diimide as a New Receptor for PAHs: An Experimental and Theoretical Study

“…The optimal geometry of the perylene‐PDI complex appears in Figure 11. The perylene molecule lays above PDI's plane, and the distance between the centroids of the guest and the host is 3.46 Å; this value falls in the range for stable π–π complexes [35] . It is possible to observe that one PDI's hooks of PDI rotates to reduce the repulsion between the protons of both fragments.…”

“…The perylene molecule lays above PDI's plane, and the distance between the centroids of the guest and the host is 3.46 Å; this value falls in the range for stable π-π complexes. [35] It is possible to observe that one PDI's hooks of PDI rotates to reduce the repulsion between the protons of both fragments. The other hook reduces its intramolecular distance to compensate for the effect caused by the guest molecule.…”

Triple-armed aliphatic tricarboxylic acids as sources of ligands for uranyl ion: influence of bridgehead functionalization

“…While the role of metal ions in coordination polymers and frameworks can be purely structural, particular properties of the metal ions such as magnetism, redox activity, electronic absorption, luminescence, stereochemical preferences, and catalytic activity can also be critical in regard to any applications, as is evident in numerous recent research articles and reviews. 31 A further tool of structural control can arise from internal functionality of the bridging ligands, 9 simple examples being where an additional donor atom provides a site for chelation 32 or, more commonly, where stacking arrays 33 are formed by small aromatic units, 34 although once again such functionality in more sophisticated forms, 35,36 has been exploited to engender special properties in the structures formed. In the particular case of tripodal ligands, the nature of the bridgehead is of prime importance, 37 as shown in the present case.…”