Crystal engineering



  synthon and the secondary building unit.

History of term

The term ‘crystal engineering’ was first used in 1971 by Schmidt[1] in connection with photodimerisation reactions in crystalline cinnamic acids. Since this initial use, the meaning of the term has broadened considerably to include many aspects of solid-state supramolecular chemistry. A useful modern definition is that provided by Desiraju, who in 1989 defined crystal engineering as “the understanding of intermolecular interactions in the context of crystal packing and the utilization of such understanding in the design of new solids with desired physical and chemical properties”. Since many of the bulk properties of molecular materials are dictated by the manner in which the molecules are ordered in the solid state, it is clear that an ability to control this ordering would afford control over these properties.

Non-covalent control of structure

Crystal engineering relies on hydrogen bonds and coordination bonds.

crystal structures, and this forms the basis for heuristic or synthon-based or "experimental" crystal engineering.

Polymorphism

Polymorphism is the phenomenon wherein the same chemical compound exists in different crystal forms. In the initial days of crystal engineering, polymorphism was not properly understood and incompletely studied. Today, it is one of the most exciting branches of the subject partly because polymorphic forms of drugs may be entitled to independent patent protection if they show new and improved properties over the known crystal forms. With the growing importance of generic drugs, the importance of crystal engineering to the pharmaceutical industry is expected to grow exponentially.

Specialized Journals

Crystal engineering is a rapidly expanding discipline as revealed by the recent appearance of several international scientific journals in which the topic plays a major role. These include CrystEngComm from the American Chemical Society.

References

  1. ^  G. M. J. Schmidt, Pure Appl. Chem., 1971, (27), 647
  2. ^  Venkat R. Thalladi, B. Satish Goud, Vanessa J. Hoy, Frank H. Allen, Judith A. K. Howard and Gautam R. Desiraju, Chemical Communications, 1996, 401-402 Abstract

See also

External links

  • Crystal Growth and Design
  • Cambridge Structural Database
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Crystal_engineering". A list of authors is available in Wikipedia.