Exploring the coordination chemistry of a low symmetry, bent dipyridyl ligand

Abstract

Although dipyridyl ligands are ubiquitous in their use within coordination polymers, the vast majority of these are symmetrical species (i.e. typically having a C2 axis passing through their core) based on para-substituted pyridyl groups which aids in the predictability of the networks or complexes that they form. Less symmetric species are often more difficult to utilize in the formation of predictable networks and are typically reliant on “post-synthetic rationalization” of the materials that are formed. Herein, we report an asymmetric dipyridyl ligand (L) which has a relatively rigid “kink,” and its use in the formation of several coordination polymers. Detailed structural comparison reveals the ligand to be relatively predictable with a predisposition to making M2L2 cyclic motifs due to the angle subtended between the two coordinating groups. In several instances the size of the motif formed provides a cavity in which aromatic species can reside.