James McCusker

Research

Synthesis and Spectroscopy of Transition Metal Complexes

(Research Description PDF)

The McCusker Group is interested in the physical and photophysical properties of  transition  metal  complexes. Our approach relies on a confluence of synthetic chemistry, a host of physical techniques ranging from magnetism to femtosecond time-resolved spectroscopy, and high-level theory. The simultaneous examination of chemical problems on all three of these fronts places us in a unique position to explore the physical chemistry of inorganic compounds.

Ultrafast Spectroscopy of Transition Metal Complexes. Our research efforts in this area concern the short time scale photo-induced dynamics of transition metal complexes.  By “short time scale”, we refer to processes occurring between the time a photon is absorbed by a molecule and the point at which that molecule is fully relaxed in its lowest-lying excited state. Some of the questions we are addressing with this research include the following: 1) what is the general time scale for excited-state evolution in transition metal complexes? 2) what is the mechanism of this process? 3) how do the geometric and electronic structures of the compounds, the surrounding medium, and other factors couple to and/or influence this process? and 4) to what extent can we use this information to control excited-state dynamics?  Certain of these questions are very fundamental in nature, whereas others are geared toward work on solar energy conversion.  What distinguishes the group, we believe, is our ability to carry out both the synthesis and spectroscopic characterization of a wide range of inorganic molecules.  This enables us to systematically examine chemical perturbations to excited-state electronic and geometric structure, and in so doing develop a comprehensive picture of how transition metal chromophores absorb and dissipate energy.

Spin and Spin Polarization Effects on Excitedstate Dynamics. Electron spin is a fundamental property of Nature. Although many of the more common physical observables linked to spin are well documented (e.g., magnetism), the degree to which spin and spin polarization influences the chemistry of molecular systems is not as clear. We are pursuing the design and development of chemical systems that will allow us to determine whether there exists a cause-and-effect relationship between the physical  and  photophysical  properties  of molecules and their innate spin properties, and if so, to what extent can we exploit this connection in order to manipulate the chemistry of molecular systems. Much of this work centers on the study of so-called donor-acceptor assemblies wherein energy and electron transfer processes are being examined in systems containing spin-coupled paramagnetic  fragments.  Through  careful synthetic manipulation of these compounds, correlations between the observed excitedstate  reactivity  and  the  involvement  of spin-polarized electronic states of the donor and/or acceptor can be realized. Coupled to this experimental work are theoretical studies that exploit recent advances in density functional  theory.  We  believe  that  these combined efforts will forge an important link between  magnetisn  and  electron/energy transfer processes, thereby allowing us to establish a new paradigm in the emerging field of molecular spintronics.

Contact / Webpage

Area(s) of Interest

Inorganic (In)

Material (Ma)

Physical (Ph)

Selected Publications

Leveraging Excited-state Coherence for Synthetic Control of Ultrafast Dynamics, B.C. Paulus, S.L. Adelman, L.L. Jamula, and J.K. McCusker, Nature 2020, in press.

Outer-sphere Effects on the Ligand-field Excited-state Dynamics: Solvent Dependence of High-spin to Low-spin Conversion in [Fe(bpy)₃]²⁺, J.N. Miller and J.K. McCusker, Chem. Sci. 2020, 11, 5191 - 5204.

The Influence of Electrolyte Composition on Ultrafast Interfacial Electron Transfer in Fe-sensitized TiO₂-based Solar Cells, C.R. Tichnell, J.N. Miller, C. Liu, S. Mukherjee, E. Jakubikova, and J.K. McCusker, J. Phys. Chem. C 2020, 124, 1794 - 1811.

Electronic Structure in the Transition-metal Block and its Implications for Light Harvesting, J.K. McCusker, Science 2019, 363, 484-488.

Insights into the Excited-state Dynamics of Fe(II) Polypyridyl Complexes fromVariable-temperature Ultrafast Spectroscopy, M.C. Carey, S.L. Adelman, and J.K. McCusker, Chem. Sci. 2019, 10, 134-144.

Utilizing Coherence to Enhance Function in Chemical and Biophysical Systems, G.D. Scholes, G.R. Fleming, L.X. Chen, J.K. McCusker, et al., Nature 2017, 543, 647-656.

Photosensitized, Energy Transfer-mediated Organometallic Catalysis through Electronically Excited Ni(II), E.R. Welin, C. Le, D.M. Arias-Rotondo, J.K. McCusker, and D.W.C. MacMillan, Science 2017, 355, 380–385.

The Photophysics of Photoredox Catalysis: A Roadmap for Catalyst Design, D.M. Arias-Rotondo and J.K. McCusker, Chem. Soc. Rev. 2016, 45, 5803–5820 (cover article).

CV

B.S. and M.S., 1987, Bucknell Univ.

Ph.D., 1992, Univ. of Illinois at Urbana Champaign

NIH Post-Doctoral Fellow, 1992-94, Univ. of North Carolina at Chapel Hill

Hellman Faculty Fellow, 1997-98, Univ. of California at Berkeley

Alfred P. Sloan Fellow, 1998-2000

Awards

Year	Award	Organization
2020	Royal Society of Chemistry Honor
2018	Foundation Professor	Michigan State University
2016	Fellow of Royal Society of Chemistry	Royal Society of Chemistry
2016	Outstanding Faculty Award	Michigan State University (College of Natural Science)
2013	CNS Junior Faculty Mentoring Award
2011	Councilor to the American Chemical Society by the Division of Inorganic Chemistry
2005	Program Committee	International Conference on Bio-Inorganic Chemistry
2004	Awards Committee	Inter-American Photochemical Society
2003	Organizer	American Chemical Society (National Meeting - From Mixed-Valency to Single-Molecule Magnets: A Symposium in Honor of the Work of David N. Hendrickson)
2003	NSF Career Award panelist (Inorganic, Bioinorganic, and Organometallic Chemistry subdivision)	National Science Foundation
2003	Organizing Committee Member	14th Inter-American Photochemical Society Winter Meeting
2002 - 2003	Nominations and Symposia Planning Committee, Division of Inorganic Chemistry	American Chemical Society
1999	Department of Chemistry Teaching Award	University of California, Berkeley
1998 - 2000	Alfred P. Sloan Fellowship	Alfred P. Sloan Foundation
1997 - 1998	Hellman Fellow	University of California, Berkeley
1992 - 1994	Postdoctoral Fellow	National Institutes of Health
1992 - 1994	Postdoctoral Fellow	National Institutes of Health
1992	Ph.D.	University of Illinois, Urbana-Champaign
1987	Phi Beta Kappa	Phi Beta Kappa
1987	M.S.	Bucknell University
1987	Bachelor of Science	Bucknell University
1987	cum laude	Bucknell University
1987 - 1988	Graduate Fellowship	University of Illinois, Urbana-Champaign
1987	Outstanding Senior Chemistry Major of the Year	American Chemical Society ((Susquehanna Valley Section) and the Faculty of Bucknell University)
1987	Honorable Mention	National Science Foundation Graduate Fellowship Competition
1985	Phi Eta Sigma	Phi Eta Sigma