Patrick Vaccaro

Member of Yale faculty since 1990

Research Interests


Our research explores the provenance of molecular behavior, with special emphasis placed on the unique features that give rise to physical properties and chemical propensities. Ongoing experiments exploit diverse forms of optical spectroscopy to interrogate the ground-/excited-state potential energy surfaces of tractable species, thereby elucidating the coupling among electronic and nuclear degrees of freedom that mediates their structure and dynamics. When combined with detailed computational and theoretical analyses, such measurements afford a trenchant glimpse of phenomena that permeate the entire fabric of chemistry and impact upon related disciplines, including proton transfer, hydrogen bonding, non-adiabatic interactions, reaction dynamics, and chirality. Successful execution of these studies necessitates both technical innovations and conceptual advancements, with many of the linear/nonlinear spectroscopic methods used in our work (e.g., polarization-resolved resonant four-wave mixing and cavity ring-down polarimetry) first developed and implemented in our laboratories.


B.A. University of Pennsylvania, 1980
Ph.D. Massachusetts Institute of Technology, 1986
Postdoctoral Associate, Stanford University, 1986-90
IBM Postdoctoral Fellow, Stanford University, 1988-89


William C. DeVane Medal for Outstanding Scholarship & Undergraduate Teaching, 2015
Dylan Hixon ‘88 Prize for Teaching Excellence in the Natural Sciences at Yale College, 2010
Yale Graduate School Mentoring Award in the Natural Sciences, 2009
Fellow of the American Physical Society, 2007
Camille Dreyfus Teacher-Scholar Award, 1994
David and Lucile Packard Fellowship for Science and Engineering, 1992
NSF Presidential Young Investigator Award, 1991
Camille and Henry Dreyfus New Faculty Award, 1990

Recent Publications

I. W. Bulik, M. J. Frisch, and P. H. Vaccaro. “Vibrational Self-Consistent Field Theory Using Optimized Curvilinear Coordinates,” J. Chem. Phys. 147(4), 044110/1-11 (2017).

P. Lahiri, K. B. Wiberg, and P. H. Vaccaro. “Dispersive Optical Activity of (R)-Methylene Norbornene: Intrinsic Response and Solvation Effects,” J. Chem. Phys. A 121(43), 8251-8266 (2017).

D. N. Nemchick, M. K. Cohen, and P. H. Vaccaro, “Dual Hydrogen-Bonding Motifs in Complexes formed between Tropolone and Formic Acid,” J. Chem. Phys. 145(20), 204303/1-22 (2016).

Z. N. Vealey, B. Q. Mercado, and P. H. Vaccaro. “The Tropolone-Isobutylamine Complex: A Hydrogen-Bonded Troponoid Without Dominant pi-pi Interactions,” Acta. Cryst. C72, 730-737 (2016).

P. Lahiri, K. B. Wiberg, and P. H. Vaccaro. “Intrinsic Optical Activity and Large-Amplitude Displacement: Conformational Flexibility in (R)-Glycidyl Methyl Ether,” J. Phys. Chem. A 119(30), 8311-8327 (2015).

P. Lahiri, K. B. Wiberg, P. H. Vaccaro, M. Caricato, and T. D. Crawford. “Large Solvent Effects in the Optical Rotatory Dispersion of Norbornenone,” Angew. Chem. Int. Edit. 53(5), 1386-1389 (2014).