title: Spin-Orbit Coupling Drives Femtosecond Nonadiabatic Dynamics in a Transition Metal Compound.
abstract: Transient absorption measurements conducted using broadband, 6 fs laser pulses reveal unexpected femtosecond dynamics in the [IrBr6]2-model system. Vibrational spectra and the X-ray crystal structure indicate that these dynamics are not induced by a Jahn-Teller distortion, a type of conical intersection typically associated with the spectral features of transition metal compounds. Two-dimensional electronic spectra of [IrBr6]2-contain 23 cross peaks, which necessarily arise from spin-orbit coupling. Real-valued 2D spectra support a spectroscopic basis where strong nonadiabatic coupling, ascribed to multiple conical intersections, mediates rapid energy relaxation to the lowest-energy excited state. Subsequent analysis gives rise to a more generalized description of a conical intersection as a degeneracy between two adiabatic states having the same total angular momentum.
authors.affiliation: Department of Chemistry, New York University , 100 Washington Square East, New York, New York 10003, United States.
authors.forename: William P
authors.initials: WP
authors.lastname: Carbery
authors.affiliation: Department of Chemistry, New York University , 100 Washington Square East, New York, New York 10003, United States.
authors.forename: Archana
authors.initials: A
authors.lastname: Verma
authors.affiliation: Department of Chemistry, New York University , 100 Washington Square East, New York, New York 10003, United States.
authors.forename: Daniel B
authors.identifier: http://orcid.org/0000-0002-3148-5317
authors.initials: DB
authors.lastname: Turner