Faculty & Staff Directory

Professor Thomas M. Gilbert


Thomas M. Gilbert

Associate Professor
Office:  La Tourette Hall 309
Phone:  (815) 753-6896
tgilbert@niu.edu

Educational Background

Postdoctoral Fellow, University of Pittsburgh, 1987-1989

Postdoctoral Fellow, Los Alamos National Laboratory, 1985-1987

Ph.D., University of California, Berkeley, 1985

B.S., Purdue University, 1981

Curriculum Vitae pdf

Research Interests

Computational studies of:
(1) main group donor–acceptor compounds; (2) spectroscopic and photochemical behavior of bio-organic compounds; and (3) mechanisms of catalytic transition metal reactions.

 


Representative Publications

B–H Activation by frustrated Lewis pairs: borenium or boryl phosphonium cation? Dureen, M. A.; Lough, A.; Gilbert, T. M.; Stephan, D. W. (2008) Chem. Commun., DOI: 10.1039/b808348g

Synthesis and Characterization of Platinum(II)- and Platinum(IV)- Pyrophosphato Complexes. Mishur, R. J.; Zheng, C.; Gilbert, T. M.; Bose, R. N. (2008) Inorg. Chem., 47: 7972–7982.

Preparation of Aza-Polycyclic Aromatic Compounds via Superelectrophilic Cyclizations. Li, A.; Gilbert, T. M.; Klumpp, D. A. (2008) J. Org. Chem., 73: 3654–3657.

Computational Studies of [2+2] and [4+2] Pericyclic Reactions between Phosphinoboranes and Alkenes. Steric and Electronic Effects in Identifying a Reactive Phosphinoborane that Should Avoid Dimerization. Gilbert, T. M.; Bachrach, S. M. (2007) Organometallics, 26: 2672–2678.

The effect of substituents on the strength of A–Cl (A=Si, Ge, and Sn) bonds in hypervalent systems: ACl5, ACl4F, and A(CH3)3Cl2. Hao, C.; Kaspar, J. D.; Check, C. E.; Lobring, K. C.; Gilbert, T. M.; Sunderlin, L. S. (2005) J. Phys. Chem. A, 109: 2026–2034.

Pericyclic reactions between aminoboranes R2B=NR2accent and alkenes: [4+2] vs. [2+2] transition states. Bisset, K. M.; Gilbert, T. M. (2004) Organometallics, 23: 850–854.

Comparison of M-S, M-O, and M-(eta2-SO) structures and bond dissociation energies in d6 (CO)5M(SO2)nq complexes using density functional theory. Retzer, H. J.; Gilbert, T. M. (2003) Inorg. Chem., 42: 7207-7218.

Addition of polarization and diffuse functions to the LANL2DZ basis set for p-block elements. Check, C. E.; Faust, T. O.; Bailey, J. M.; Wright, B. J.; Gilbert, T. M.; Sunderlin, L. S. (2001) J. Phys. Chem. A, 105: 8111-8116.


Computational Chemistry

Research in my group focuses on elucidating the reasons why compounds adopt particular structures and react in specific ways. We attack issues computationally, using ab initio Hartree-Fock, perturbation theory, and/or density functional methods, depending upon the questions we wish to answer.

One broad topic within the group involves examining donor-acceptor compounds containing main group atoms. One area involves collaborating with Professor Doug Stephan and his group at the University of Toronto on studies of donors and acceptors containing substituents so large that they cannot bond in the usual way, so-called “frustrated Lewis pairs”, or FLPs. Several FLPs display unexpected, exciting reactivity modes such as splitting the H–H bond in H2, N–H bonds in amines, and C–H bonds in alkynes. This work may lead to new methods of hydrogen storage, which in turn may make hydrogen-burning vehicles economical. A second area involves studies of Group 13–Group 15 compounds that potentially contain multiple bonds between donor and acceptor atoms. For example, aminoboranes (R2B=NR2) and phosphinoboranes (R2B=PR2), are isoelectronic with alkenes, and show characteristic structural similarities to them. However, the two often react differently, in some cases in complete opposition to well known alkene reactions. Thus, despite the similarities, the heteroatom double bonds are electronically quite different from those in alkenes. We explore these differences by focusing on the reaction mechanisms followed by these heteroatom systems with an eye toward explaining fundamental distinctions between them and organic analogues. Third, in collaboration with Professor Sunderlin and his group at NIU, we examine the structures and energetics of hypervalent main-group compounds. These molecules, such as PCl6_ and I3, pose intriguing questions owing to their violation of the octet rule and to their use of orbitals. Our efforts focus on evaluating the reaction mechanisms available to these complex species, and on developing modeling techniques that give predictions consistent with experimental data.

In collaboration with Professor Gaillard and her group at NIU, we examine the spectroscopy and photochemistry of organic compounds found in human eyes. Such issues are involved in degradation of vision as one ages (for example, cataract formation and macular degeneration), so understanding them should assist medical treatment. We employ computational techniques such as time-dependent theories, basis set testing, and solvent modeling, to model the chemistry within the environment of the eye as closely as possible. We are now probing photochemical regioselectivity of various systems in order to predict structures of products formed in quantities sufficient to observe spectroscopically, but too small to isolate.

Calculations involving transition metal compounds are particularly demanding, but density functional models and modern, high-speed computers provide exciting means to approach problems in transition metal catalysis. We study primarily two areas: (1) transition metal-SOx chemistry, and (2) the chemistry of transition metal imides (M=NR). The former topic has many ramifications in the chemistry of air pollution. We know that sulfur oxides generated by the burning of fossil fuels represent significant pollutants; we also know that several transition metal catalysts remove them from gas streams. How these catalysts work on a molecular level, however, is not well known, nor is whether less-expensive catalysts could be used. Computations of the strength of metal-SOx bonds, and of the mechanisms by which metal-SOx compounds react, show promise in providing answers. The latter topic focuses on the remarkable imide metathesis reaction, where the NR group of an organic imide (RN=CHR’2) is exchanged for another through use of a transition metal imide. This process has many applications in organic chemistry, and involves the breaking of strong atom–imide nitrogen bonds. It thus represents a means for understanding how transition metal catalysts catalyze reactions wherein strong bonds are broken.