EXPLOITATION OF THE HYDROGEN-BOND - RECENT DEVELOPMENTS IN THE CONTEXT OF CRYSTAL ENGINEERING

The desire to design rationally technologically useful solid-slate mat erials has coupled with our ever growing understanding of the nature o f non-covalent intermolecular interactions and molecular recognition p rocesses (i.e. supramolecular chemistry) to provide impetus for the em ergence of crystal engineering. The ''golden rule'' of crystal enginee ring is that one has to assume that the architecture within crystals, and therefore the space group in which a given compound crystallizes, is determined solely by the strength and directionality of intermolecu lar or interionic interactions. In other words, most crystal structure s can be regarded as de facto manifestations of self-assembly. The obj ective of this review is to provide chemists from all disciplines with an overview of recent developments in the held with particular emphas is on how symmetry and function at the molecular level can be used to control solid-state architecture. Hydrogen bonding represents perhaps the best understood non-covalent force and is one of the primary tools available to crystal engineers so it is also a focus of the review. D evelopments in all areas of chemistry subsequent to 1988 are highlight ed, but we also cite earlier literature that deals specifically with h ydrogen bonding in the context of long-range ordering of molecules or ions.