Organometallic crystal engineering: prospects for a systematic design

Abstract

Crystal engineering is a bridge between supramolecular and materials chemistry. The use of organometallic molecules or ions in the construction of crystals with predefined architectures is a means to introduce into the crystals the variable oxidation and spin states of metal atoms as well as the specific topological requirements of coordination bonds. The perspective of an emerging organometallic crystal engineering discipline has been discussed. It has been shown through a number of examples that the presence of metal atoms makes organometallic crystal engineering distinct from organic crystal engineering. The effect of ligand topology, the ability to tune the acid/base behavior of ligands by means of ligand–metal(s) coordination, the direct participation of metal atoms in extramolecular interactions in the solid state, as well as the consequence of the ionic charges on the strength of weak and strong intermolecular hydrogen bonds have been discussed. In particular, a design strategy to obtain organic–organometallic crystals by means of a selective use of strong hydrogen bonds between the organic component and of weak hydrogen bonds between organic and organometallic components is illustrated with emphasis on the role of charge-assisted C–H δ+ ⋯O δ− hydrogen bonds.