Multi-Pole Approach to Structural Science

May 10 - 13, 2015

Exploring the wealth of specific intermolecular interactions for crystal engineering
Maria Gdaniec

Crystal engineering, a branch of supramolecular chemistry, exploits our present knowledge of intermolecular interactions and molecular recognition processes in the design and synthesis of crystalline phases. In recent years scientific interest in preparation of mono- and multi-component molecular crystals with controlled properties is rising rapidly and a number as well as a variety of applications of newly prepared solid phases is growing steadilly.

Research during the past twenty years shows that cocrystallization of chemical compounds is a more common phenomenon than initially believed and the number of new chemical substances that can be prepared in this way is practically unlimited. Strategy for the synthesis of multicomponent crystals is analogous to the startegy for supramolecular synthesis. Selection of the reagents should lead to heteromeric recognition, resulting in the formation of cocrystals, instead of homomeric recognition, resulting in separate crystallization of the substrates. Therefore the reacting molecules should be equipped with complementary, but different, functional groups able to form heterosynthons. At the very beginning crystal engineering was mainly applying conventional hydrogen bonds to link complementary functional groups, however a variety of specific intermolecular interactions with strength comparable to hydrogen bonds is getting more and more abundant.

In this presentation, the design of new multicomponent crystals with supramolecular synthons based on hydrogen, halogen and chalcogen bonds, aromatic interactions, including aryl-perfluoroaryl synthon, will be presented. The obvious next step in crystal engineering is an introduction into the crystal design process of a combination of synthons based on diverse kinds of intermolecular interactions. As a result, better understanding of supramolecular chemistry of functional groups as well as determination of the hierarchy of supramolecular synthons can be achieved. This kind of research requires however creation of modular systems where cooperation and competition of intermolecular interactions can be regulated via a systematic alteration in the structure of reagents, allowing thus for tuning of the structure and the properties of multi-component crystals.