Ligand geometry directs the packing and symmetry of one-dimensional helical motifs in lead oxide naphthoates and biphenylcarboxylates

Abstract

Extended inorganic hybrids are highly tunable, with changes in the identity of each component giving rise to a variety of different architectures and symmetries. Lead oxide carboxylates are a family of extended inorganic hybrids in which inorganic substructures based on edge-sharing Pb₄O tetrahedra are further coordinated by carboxylate ligands. It has previously been shown that the dimensionality of these compounds correlates with the noncoordinating to coordinating volume ratio of the organic ligand. Here, we present five novel lead oxide carboxylates – two with isomeric naphthoate ligands and three with isomeric biphenylcarboxylate ligands – in order to address the role of ligand geometry in directing the spatial arrangement and symmetry of inorganic motifs in these compounds. The compounds have been characterized by single crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis, and elemental analysis. In these compounds, the spatial arrangement of helical inorganic chains is controlled by the extent to which ligands on a given chain fill space immediately surrounding that chain. Noncovalent interaction index calculations have been undertaken for the naphthoate compounds in order to visualize the role of aromatic-aromatic interactions in stabilizing the structures. The structural patterns found here may be applicable to other hybrid systems containing one-dimensional, extended inorganic substructures.