Supramolecular chemistry and crystal engineering

Advances in supramolecular chemistry and crystal engineering reported from India within the last decade are highlighted in the categories of new intermolecular interactions, designed supramolecular architectures, network structures, multi-component host-guest systems, cocrystals, and polymorphs. Understanding self-assembly and crystallization through X-ray crystal structures is illustrated by two important prototypes - the large unit cell of elusive saccharin hydrate, Na-16(sac)(16)center dot 30H(2)O, which contains regular and irregular domains in the same structure, and by the Aufbau build up of zinc phosphate framework structures, e. g. ladder motif in [C3N2H12][Zn(HPO4)(2)] to layer structure in [C3N2H12][Zn-2(HPO4)(3)] upon prolonged hydrothermal conditions. The pivotal role of accurate X-ray diffraction in supramolecular and structural studies is evident in many examples. Application of the bottom-up approach to make powerful NLO and magnetic materials, design of efficient organogelators, and crystallization of novel pharmaceutical polymorphs and cocrystals show possible future directions for interdisciplinary research in chemistry with materials and pharmaceutical scientists. This article traces the evolution of supramolecular chemistry and crystal engineering starting from the early nineties and projects a center stage for chemistry in the natural sciences.