Crystal Engineering of Task-Specific Materials

That composition and structure profoundly impact the properties of crystalline solids has provided impetus for exponential growth in the field of crystal engineering1 over the past 25 years. This lecture will address how crystal engineering has evolved from structure design (form) to control over bulk properties (function). Strategies for the generation of two classes of functional crystalline materials will be addressed:
Multicomponent pharmaceutical materials, MPMs, such as cocrystals2 have emerged at
the preformulation stage of drug development. This results from their modular and designable nature which facilitates the discovery of new crystal forms of active pharmaceutical ingredients, APIs, with changed physicochemical properties. The concepts of “supramolecular heterosynthons” and “ionic cocrystals” will be explained and a case study addressing brain bioavailability of lithium will be presented.
Hybrid Porous Materials (HPMs) are built from metal or metal cluster “nodes” and
combinations of organic and inorganic “linkers”. A family of HPMs, pillared grids, that afford exceptional control over pore chemistry, pore size and binding energy,3 will be detailed. Benchmark selectivity for CO2 capture in narrow pore HPMs with pcu or mmo (see Figure) topology has been observed thanks to the strong electrostatics associated with pores lined by the inorganic components of these nets.
Multinodal nets can also offer exceptional opportunities for fine-­‐tuning and can be designed the simplest of nodes and linkers. However, they remain understudied because of the synthetic challenges associated with self-­‐assembly of multiple nodes. Interpenetrated 3D nets, another understudied class of material, also afford control over pore size and can result in materials with exceptional gas sorption performance.4
In summary, this lecture will emphasize how the crystal engineering coupled with molecular modeling offers a paradigm shift from the more random, high-­‐throughput methods that have traditionally been utilized in materials discovery and development. In short, how to make the right material for the right application.
References
1. (a) Desiraju, G.R. Crystal engineering: The design of organic solids Elsevier, 1989; (b) Moulton, B.; Zaworotko, M.J. Chemical Reviews 2001, 101, 1629-­‐1658.
2. Vishweshwar, P.; McMahon, J.A.; Bis, J.A.; Zaworotko, M.J. J. Pharm. Sci. 2006, 95, 499-­‐516, 2006.
3. Smith, A.J.; Kim, S.-­‐H.; Duggirala, N.K.; Jin, J.; Wojtas, L.; Ehrhart, J.; Giunta, B.; Tan, J.; Zaworotko, M.J.; Shytle, R.D. Molecular Pharmaceutics, 10, 4728-­‐4738, 2013.
3. (a) Burd, S.D.; Ma, S.; Perman, J.A.; Sikora, B.J.; Snurr, R.Q.; Thallapally, P.K.; Tian, J.; Wojtas, L.; Zaworotko, M.J. J. Amer. Chem. Soc. 2012, 134, 3663-­‐3666. (b) Mohamed, M.; Elsaidi, S.; Wojtas, L.; Pham, T.; Forrest, K.A.; Tudor, B..; Space, B.; Zaworotko, M.J. J. Amer. Chem. Soc. 2012, 134, 19556-­‐
19559. (c) Nugent, P.; Belmabkhout, Y.; Burd, S.D.; Cairns, A.J.; Luebke, R.; Forrest, K.; Pham, T.; Ma, S.; Space, B.; Wojtas, L.; Eddaoudi, M.; Zaworotko, M.J. Nature 2013, 495, 80-­‐84, 2013.
4. Elsaidi, S.K; Mohamed, M.H.; Wojtas, L.; Chanthapally, A.; Pham, T.; Space, B.; Vittal, J.J.; Zaworotko, M.J. J. Amer. Chem. Soc. 136, 5072-­‐5077, 2014.