Faculty Assistant

Pattie Faranetta
Frick Laboratory, 228

Research Focus

The Weichman Lab will develop novel spectroscopic tools to examine chemical interactions in nanoscale and hybrid light-matter systems, harness control of these systems, and explore both their fundamental properties and broader applications in catalysis, synthesis, and materials.


Catalysis and quantum control of reactions via strong light-matter coupling

Most key chemical problems lie in the transformation of molecular material into desired products or useful energy. Optimizing the path of a reaction typically hinges on modifying chemical substituents or reaction conditions. There is a need for novel, broadly applicable tools to better manipulate the efficiency and specificity of complex reactive processes.

Polaritons, hybrid quantum states arising through strong light-matter interactions, have great prospects for rationally manipulating reaction pathways, photochemistry, and energy transfer, and await application to open chemical problems. We will lay the groundwork to understand the effects of vibrational and electronic strong coupling on reactions occurring on ground and excited state surfaces, and subsequently explore their utility for novel catalytic methods and devices.


Quantum state resolved dynamics in cold nanoscale molecules

A rigorous understanding of structure and dynamics in pristine, isolated, and typically small molecular systems has been made possible through high resolution spectroscopy. Extending this level of characterization to systems of transitional size, on the brink of treatment with standard molecular tools, is becoming possible using novel optical and cold molecule technologies. We will use cavity-enhanced frequency comb spectroscopy and buffer gas cooling techniques to fully resolve individual quantum states in unprecedentedly complex molecular systems. The combination of broadband, sensitive, and high-resolution frequency comb spectroscopy with cold molecule sources will facilitate future research avenues in laboratory astrophysics, aerosol science, and state preparation of large molecules.

Research Areas
Spectroscopy / Physical Chemistry

NIST/NRC Postdoctoral Research Fellow (2017-2019)

APS Justin Jankunas Doctoral Dissertation Award in Chemical Physics (2018)

NSF Graduate Research Fellow (2012-2017)

Selected Recent Publications

P. B. Changala, M. L. Weichman, K. F. Lee, M. E. Fermann, and J. Ye. Rovibrational quantum state resolution of the C60 fullerene. Science 363, 49-54 (2019).

M. L. Weichman, P. B. Changala, M. Yan, N. Picqué, and J. Ye. Broadband molecular spectroscopy with optical frequency combs. J. Mol. Spec. 355, 66-78 (2019).

M. L. Weichman and D. M. Neumark. Slow photoelectron velocity-map imaging spectroscopy of cryogenically cooled anions. Annu. Rev. Phys. Chem. 69, 101-124 (2018).

M. L. Weichman, S. Debnath, J. T. Kelly, S. Gewinner, W. Schöllkopf, D. M. Neumark, and K. R. Asmis. Dissociative water adsorption on gas-phase titanium dioxide cluster anions probed with infrared photodissociation spectroscopy. Top. Catal. 61, 92-105 (2018).

J. A. DeVine, M. L. Weichman, B. Laws, J. Chang, M. C. Babin, G. Balerdi, C. Xie, C. L. Malbon, W. C. Lineberger, D. R. Yarkony, R. W. Field, S. T. Gibson, J. Ma, H. Guo, and D. M. Neumark. Encoding of vinylidene isomerization in its anion photoelectron spectrum. Science 358, 336-339 (2017).

M. L. Weichman, J. A. DeVine, M. C. Babin, J. Li, J. Ma, H. Guo, and D. M. Neumark. Feshbach resonances in the exit channel of the F + CH3OH → HF + CH3O reaction observed using transition-state spectroscopy. Nat. Chem. 9, 950-955 (2017).

M. L. Weichman, J. A. DeVine, D. S. Levine, J. B. Kim, and D. M. Neumark. Isomer-specific vibronic structure of the 9-, 1-, and 2-anthracenyl radicals via slow photoelectron velocity-map imaging. Proc. Natl. Acad. Sci. U.S.A. 113, 1698-1705 (2016).

J. B. Kim, M. L. Weichman, T. F. Sjolander, D. M. Neumark, J. Kłos, M. H. Alexander, and D. E. Manolopoulos. Spectroscopic observation of resonances in the F + H2 reaction. Science 349, 510-513 (2015).

M. L. Weichman, J. B. Kim, J. A. DeVine, D. S. Levine, and D. M. Neumark. Vibrational and electronic structure of the α- and β-naphthyl radicals via slow photoelectron velocity-map imaging. J. Am. Chem. Soc. 137, 1420-1423 (2015).