Crystal Engineering—Designing Complexity

Abstract

Crystal Clear: Engineering Complexity combines Gautam R. Desiraju’s scientific autobiography with an account of the emergence of modern crystal engineering. Beginning with his childhood in Madras and Bombay, his education in chemistry and doctoral training in the United States, and his deliberate return to India, Desiraju recounts a research career spanning more than five decades. Difficult working conditions at the newly established University of Hyderabad did not lead to his withdrawal from international science, but instead produced an idea- and data-driven research strategy that transformed institutional limitations into intellectual independence. The scientific core of the book is the recognition that directional intermolecular interactions organize the packing of organic molecules and can therefore be used in the deliberate design of crystalline solids. The Cambridge Structural Database made recurring patterns visible even among weak interactions. With the supramolecular synthon, Desiraju transferred the logic of retrosynthesis to crystals: molecular fragments and noncovalent bonds became designable building blocks in a new form of organic synthesis. His work on weak hydrogen bonds also broadened the chemical understanding of bonding and demonstrated that interactions of low energy may nevertheless define structure. Polymorphism and crystal structure prediction led to a broader understanding of the crystal as a complex system. A molecule does not necessarily possess one unique crystal structure, but rather a landscape of possible forms whose realization depends on kinetics, thermodynamics, and crystallization conditions. Later work on mechanical properties, pharmaceutical solid forms, and higher cocrystals extended crystal engineering from structural planning to the deliberate design of material properties. In parallel, the book describes Desiraju’s engagement with the Indian scientific system, his international work within the IUCr, and his role in the International Year of Crystallography and the 2017 IUCr Congress in Hyderabad. In the concluding chapters, he develops a personal philosophy of science that connects reductionism and holism, chemistry and complexity, and scientific work with social responsibility. Indian Knowledge Systems and the idea of Bhārat provide the cultural and political frame of reference. The book is therefore at once a research biography, a history of a discipline, an institutional testimony, and a personal argument for curiosity, courage, nonconformity, and the unity of the scientific search for knowledge.