title: Broad-Band Pump-Probe Spectroscopy Quantifies Ultrafast Solvation Dynamics of Proteins and Molecules.
abstract: In this work, we demonstrate the use of broad-band pump-probe spectroscopy to measure femtosecond solvation dynamics. We report studies of a rhodamine dye in methanol and cryptophyte algae light-harvesting proteins in aqueous suspension. Broad-band impulsive excitation generates a vibrational wavepacket that oscillates on the excited-state potential energy surface, destructively interfering with itself at the minimum of the surface. This destructive interference gives rise to a node at a certain probe wavelength that varies with time. This reveals the Gibbs free-energy changes of the excited-state potential energy surface, which equates to the solvation time correlation function. This method captures the inertial solvent response of water (∼40 fs) and the bimodal inertial response of methanol (∼40 and ∼150 fs) and reveals how protein-buried chromophores are sensitive to the solvent dynamics inside and outside of the protein environment.
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Chanelle C
authors.initials: CC
authors.lastname: Jumper
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.|Department of Physics, California State University, Chico , Chico, California 95929-0202, United States.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Arpin
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.|Department of Chemistry, New York University , 100 Washington Square East, New York, New York 10003, United States.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Turner
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Scott D
authors.initials: SD
authors.lastname: McClure
authors.affiliation: Department of Chemistry, Princeton University , Washington Road, Princeton, New Jersey 08544, United States.
authors.forename: Shahnawaz R.
authors.initials: SR
authors.lastname: Rather
authors.affiliation: Department of Chemistry, Princeton University , Washington Road, Princeton, New Jersey 08544, United States.
authors.forename: Jacob C
authors.initials: JC
authors.lastname: Dean
authors.affiliation: Department of Chemistry and Biochemistry, and Oregon Center for Optical, Molecular, and Quantum Science, University of Oregon , Eugene, Oregon 97403, United States.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Cina
authors.affiliation: Department of Chemistry and Biochemistry, and Oregon Center for Optical, Molecular, and Quantum Science, University of Oregon , Eugene, Oregon 97403, United States.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Kovac
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Tihana
authors.initials: T
authors.lastname: Mirkovic
authors.affiliation: Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.|Department of Chemistry, Princeton University , Washington Road, Princeton, New Jersey 08544, United States.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Scholes