Career in crystal engineering

 

 Crystal engineering is the design and synthesis of molecular solid-state structures with desired properties, based on an understanding and exploitation of intermolecular interactions. The two main strategies currently in use for crystal engineering are based on hydrogen bonding and coordination complexation. These may be understood with key concepts such as the supramolecular synthon and the secondary building unit.

 The term ‘crystal engineering’ was first used in 1971 by Schmidt 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 Gautam Radhakrishna Desiraju, who in 1988 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.

Crystal engineering is a branch of science, which involves the design of crystals with desired properties keeping in mind the understanding between intermolecular interactions. Gautam R Desiraju, a noted chemist who teaches and works at the Indian Institute of Science (IISc), Bangalore, recently spoke about this relatively unknown discipline of science during a conference held at the Jawaharlal Nehru University (JNU).

“Crystal engineering demands a detailed and thorough knowledge of intermolecular interactions, which act as the supramolecular glue that binds molecules into crystals,” said Desiraju.

During the talk, Desiraju further explained the role of a crystal engineer. “The work of crystal engineers is to deliberately design a crystal and know if the crystal being made is actually functional. It is an area that borrows from different streams of thought and attracts attention from organic, physical chemists, crystallographers and material scientists,” he said.

As a subject, crystal engineering is taught in IISc (Bangalore), University of Hyderabad, IIT Kanpur, the Indian Association for the Cultivation of Science and IIT-Delhi. However, it only features as a semester course. “Crystal engineering as a field needs more attention. There is a need for this subject to be taught as an elective course,” informed Desiraju.