Leonard R. MacGillivray
- B.S., Saint Mary's University (1994)
- Ph.D., University of Missouri-Columbia (1998)
- Research Associate, Steacie Institute for Molecular Sciences, National Research Council of Canada (1998-2000)
- Adjunct Research Professor, Ottawa-Carleton Chemistry Institute (1999-2000)
Molecular recognition; solid state organic and inorganic chemistry; crystal photochemistry; nanotechnology. Synthesis of porous molecular solids and nanometer scale molecular structures for applications in separations, catalysis, and molecular switching. Organic solid state synthesis by design.
Whereas more traditional approaches to chemical synthesis have focused upon atoms and molecules individually, our research encompasses understanding principles that govern the effects of intermolecular interactions (e.g. hydrogen bonds) on the structure and properties of assemblies of atoms and molecules in the field of supramolecular chemistry. The structure of DNA and ability of enzymes to catalyze chemical reactions are examples from biochemistry that are regulated by such interactions and we address whether such forces may be used to confront long-standing problems with new perspectives or design new molecules and materials with unique properties.
Materials Design. It is well established that molecular approaches to crystal structure design can lead to new materials with desirable properties (e.g. optical). Despite this realization, an insufficient knowledge of factors that dictate crystal packing has hindered chemists from designing molecules that assemble to form functional solids, a priori, with predictable properties. This problem of crystal structure design, referred to as a problem of crystal engineering, is similar to solution phase organic synthesis in that chemists must plan routes, involving structural units known as synthons, to targeted, functional molecular systems. However, whereas solution phase organic synthesis is at a stage where synthetic routes are being reexamined to reduce steps for atom economy, the field of rational solid state design is at a stage where synthons are beginning to be identified.
Of the properties that may be exploited for the design of molecular solids, it is solid state reactivity, in the form of bimolecular reactions, that we are studying. Such an approach to synthesis holds great promise for the designed, solvent-free synthesis of molecules, and materials, available either in low yields, as part of mixtures, or are completely inaccessible in the liquid phase. Unfortunately, however, most approaches to synthesis in the solid state are generally unreliable such that reaction homology, a concept central to the development of solution phase molecular synthesis, has been achieved with limited success. We are addressing this problem of reaction homology, using an approach that controls reactivity in solids by employing molecules that serve, via molecular recognition processes based on hydrogen bonds, as linear templates (see Figure 1), with the prospect that a reliable method for conducting reactions in the solid state will permit us to establish novel applications for the reactants (e.g. green chemistry), products (e.g. nanostructures), and materials (e.g. molecular devices).
Figure 1. ORTEP perspectives of: (a) 2(resorcinol)·2(trans-1,2-bis(4-pyridyl)ethylene) and (b) 2(resorcinol)·rctt-tetrakis(4-pyridyl)cyclobutane. A photoinduced [2+2] cycloaddition in the solid state yields a cyclized product in which the diol directs formation of two covalent bonds by way of four O-H···N hydrogen bonds.
With an interdisciplinary program that spans materials science and synthetic chemistry, students in our group are encouraged to face problems from a variety of perspectives, an approach that is becoming increasingly necessary as the lines between more traditional areas continue to be broken. Thus, in addition to developing synthetic methodologies, students, and other researchers, gain hands-on experience with state-of-the-art techniques of materials science (e.g. single-crystal X-ray analysis).
- Papaefstathiou, G.S.; Duncan, A.J.; MacGillivray, L.R., “Two Act as One: Unexpected Dimers of Catechol Direct a Solid-state [2+2] Photodimerization in a Six-Component Hydrogen-Bonded Assembly”, ChemCommun. 2014, 50, 15960-15962.
- Hutchins, K.M.; Rupasinghe, T.; Ditzler, L.; Swenson, D.; Sander, J.; Baltrusaitis, J.; Tivanski, A.; MacGillivray, L.R., “Nanocrystals of a Metal-Organic Complex Exhibit Remarkably High Conductivity that Increases in a Single-Crystal-to-Single-Crystal Transformation”, J. Am. Chem. Soc. 2014, 136, 6778-6781.
- Hutchins, K.M.; Dutta, S.; Loren, B.P.; MacGillivray, L.R., “Co-crystals of a Salicylideneaniline: Photochromism Involving Planar Dihedral Angles”, Chem. Mater. 2014, 26, 3042-3044.
- Hutchins, K.M.; Sumrak, J.C.; MacGillivray, L.R.; “Resorcinol-Templated Head-to-Head Photodimerization of a Thiophene in the Solid State and Unusual Edge-to-Face Stacking in a Discrete Hydrogen-Bonded Assembly”, Org. Lett. 2014, 16, 1052-1055.
- Stojakovic, J.; Whitis, A.M.; MacGillivray, L.R., “Discrete Double-to-Quadruple Aromatic Stacks: Stepwise Integration of Face-to-Face Geometries in Cocrystals Based on Indolocarbazole”, Angew. Chem., Int. Ed., 2013, 52, 12127-12130.