B.S. Beloit College (2001) Ph.D. University of Notre Dame (2008) Postdoctoral Research Associate, NEAT-ORU, University of California at Davis (2008-2010)

Inorganic Chemistry

Fundamental Actinide Chemistry

Actinides have fascinating chemical properties due to the complex nature of their 5f electrons that may lead to unique catalytic, electronic, and optical properties. Of particular interest is the development of novel actinide nanomaterials for use in advanced technologies and as geochemical model compounds to understanding the mobility of nuclear waste in environmental systems. We use a variety of low-temperature synthesis techniques to create novel materials containing thorium (232Th) and uranium (238U) that are characterized by single-crystal X-ray diffraction, NMR, Raman and IR spectroscopy, and thermogravimetric analysis.

Development of Metal Organic Nanotubes

The development of novel nanomaterials with unique water transport and storage properties is important to technological advances in separations, catalysis, drug delivery, and environmental remediation. Development of novel hybrid materials, such as metal-organic nanotubes (MONs) are of particular interest as they are amenable to structural engineering strategies and may exhibit unique properties based upon the presence of inorganic components. The Forbes Research Group has recently synthesized and structurally characterized a unique U(VI) MON that displays permanent porosity and thermal stability. The compound contains ordered water that structurally resembles Ih ice and exhibits low-temperature, reversible water adsorption that can be controlled by solvent polarity. “Ice channels” within single-walled carbon nanotubes have been predicted by computational methods, but the structural nature of nanoconfined water has yet to be determined experimentally. We are currently developing novel MONs based upon actinide, main-group, and transition metals that can be developed into novel water purification membranes and separations technologies. This research is supported by NSF Career Award – Division of Solid State and Materials Chemistry.

The uranium-based metal organic nanotubes contain “ice channels” within the center of the nanotube and display unique selectivity to water.

Transport of Nuclear Waste and Heavy Metals in Environmental Systems

Actinides are a major source of radioactivity associated with nuclear waste and their transport in environmental systems is enhanced through adsorption onto small (1-5 nm) nanoparticles. The Forbes research group synthesizes novel actinide nanomaterials that are used as geochemical model compounds to enhance our understanding of the mobility of nuclear materials in environmental systems. Single-crystal X-ray diffraction and synchrotron techniques, such as high-energy X-ray scattering, are used to provide a molecular-level understanding of the structural characteristics of the 232Th and 238U complexes that will aid in the development of novel remediation methods for nuclear materials.

We also investigate the adsorption of heavy metals onto small aluminum and iron oxyhydroxide particles to provide a molecular level understanding of contaminant transport in environmental systems by synthesizing and structurally characterizing geochemical model compounds. These compounds are also investigated by computational methods through collaborations with Dr. Sara Mason in the Physical Chemistry Division. In addition, the transport of these particles through geologic media is being explored through collaborations with Dr. Adam Ward in the Department of Earth and Environmental Sciences. This research is currently supported by the Nuclear Regulatory Commission, Faculty Development Award.

The synthesis and characterization of aluminum oxyhydroxide nanoparticles that are 2 nm in diameter have provided insight into the adsorption of heavy metals within environmental systems.

Unruh, D. K.; de Groot, J.; Fairley, M.; Libo, A.; Miller, S.; and Forbes, T.Z.* "Interplay of Condensation and Chelation in Binary and Ternary Th(IV) Systems." (2015) Inorganic Chemistry Article ASAP. link Basile, M.; Unruh, D. K.; Gojdas, K.; Flores, E.; Streicher, L.; and Forbes, T.Z.* "Chemical controls on uranyl citrate speciation and the self-assembly of nanoscale macrocycles and sandwich complexes in aqueous solution." (2015) ChemComm Advance Article. link Basile, M., D. K. Unruh, E. Flores, A. Johns, and Tori Z. Forbes*. "Structural characterization of environmentally relevant ternary uranyl citrate complexes present in aqueous solutions and solid state materials." (2015) Dalton Transactions 44, 2597-2605. link Sahu, Sulata K., D. K. Unruh, T. Z. Forbes*, and A. Navrotsky. "Energetics of Formation and Hydration of a Porous Metal Organic Nanotube." (2014) Chemistry of Materials 26 (17), 5105-5112. link Unruh, D. K., A. Libo, L. Streicher, and T. Z. Forbes*. "Synthesis and characterization of 1-D uranyl thiodigycolate coordination polymers." (2014) Polyhedron 73, 110-117. link de Groot, J., K. Gojdas, D. K. Unruh, and T. Z. Forbes*. "Use of Charge-Assisted Hydrogen Bonding in the Supramolecular Assembly of Hybrid Uranyl Materials." (2014) Crystal Growth and Design 14 (3), 1357-1365. link Abeysinghe, S., K. W. Corum, D. L. Neff, S. E. Mason*, and T. Z. Forbes*. "Contaminant Adsorption on Nanoscale Particles: Structural and Theoretical Characterization of Cu2+ Bonding on the Surface of Keggin-Type Polyaluminum (Al30) Molecular Species." (2013) Langmuir 29 (46), 14124-14134. link Unruh, D. K., K. Gojdas, E. Flores, A. Libo, and T. Z. Forbes*. "Synthesis and Structural Characterization of Hydrolysis Products within the Uranyl Iminodiacetate and Malate Systems" (2013) Inorganic Chemistry 52 (17), 10191-10198. link Fairley, M., D. K. Unruh, A. Donovan, S. Abeysinghe, and T. Z. Forbes*. "Synthesis and characterization of homo- and heteronuclear molecular Al3+ and Th4+ species chelated by the ethylenediaminetetracetate (edta) ligand." (2013) Dalton Transactions 42, 13706-13714. link Unruh, D. K., K. Gojdas, A. Libo, and T. Z. Forbes*. "Development of Metal-Organic Nanotubes Exhibiting Low-Temperature, Reversible Exchange of Confined "Ice Channels."" (2013) Journal of the American Chemical Society 135 (20), 7398-7401. link Abeysinghe, S., D. K. Unruh, and T. Z. Forbes*. "Surface Modification of Al30 Keggin-Type Polyaluminum Molecular Clusters." (2013) Inorganic Chemistry 52 (10), 5991-5999. link Alessi, D. S., J. E. S. Szymanowski, T. Z. Forbes, A. N. Quicksall, G. E. Sigmon, P. C. Burns, J. B. Fein. "Mineralogic controls on aqueous neptunium(V) concentrations in silicate systems." (2013) Journal of Nuclear Materials 433, 233-239. link Fairley, M., D. K. Unruh, S. Abeysinghe, and T. Z. Forbes*. "Synthesis and Structural Characterization of Heterometallic Thorium Aluminum Polynuclear Molecular Clusters." (2012) Inorganic Chemistry 51 (17), 9491-9498. link Abeysinghe, S., D. K. Unruh, and T. Z. Forbes*. "Crystallization of Keggin-Type Polyaluminum Species by Supramolecular Interactions with Disulfonate Anions." (2012) Crystal Growth and Design 12 (4), 2044-2051. link Forbes, T.Z., A.V. Radha, and A. Navrotsky "The energetics of nanophase calcite." (2011), Geochimica et Cosmochimica Acta. 24(15) 7893-7905. link Forbes, T.Z., J. Kurzman, R. Sedhedri, and A. Navrotsky "The energetics of La4LiAuO8." (2011) Journal of Materials Research 26(10) 1188-1192. link Forbes, T.Z., D. McInnis, P. Horan, T. Devine, and P.C. Burns. "Alteration of secondary uranyl mineral analogues in the presence of hydrogen peroxide." (2011) American Mineralogist 96(1) 202-206. link Forbes, T.Z., M. Nyman, M.A. Rodriguez, and A. Navrotsky. "Energetics of Lanthanum Tantalate Materials." (2010) Journal of Solid State Chemistry 183(11) 2516-2521. link Radha, A. V., T.Z. Forbes, C. Killian, P.U.P.A. Gilbert, and A. Navrotsky. "Transformation and Crystallization Energetics of Synthetic and Biogenic Amorphous Calcium Carbonate." Proceedings of the National Academy of Sciences (2010) 107(38) 16438-16443. link Forbes, T.Z., and S.C. Sevov. "Metal-Organic Frameworks with Direct Transition Metal-Sulfonate Interactions and Charge-Assisted Hydrogen Bonds." Inorganic Chemistry (2009) 48(14) 6873-6878. link