title: Comment on "Engineering coherence among excited states in synthetic heterodimer systems".
abstract: Hayes et al. (Reports, 21 June 2013, p. 1431) used two-dimensional (2D) electronic spectroscopy to study molecular heterodimers and reported a general mechanism for the prolongation of electronic coherences, consistent with previous interpretations of 2D spectra for light-harvesting systems. We argue that the dynamics attributed to electronic coherences are inconclusive based on experimental inconsistencies arising from limited sample characterization and insufficient control measurements.
authors.affiliation: Institute for Optical Sciences and Departments of Chemistry and Physics, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Alexei
authors.initials: A
authors.lastname: Halpin
authors.affiliation: Institute for Optical Sciences and Departments of Chemistry and Physics, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Philip J M
authors.initials: PJ
authors.lastname: Johnson
authors.affiliation: Institute for Optical Sciences and Departments of Chemistry and Physics, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada. Max Planck Institute for the Structure and Dynamics of Matter, Atomically Resolved Dynamics Division, Building 99 (CFEL), Luruper Chaussee 149, 22761 Hamburg, Germany. dwayne.miller@mpsd.mpg.de.
authors.forename: R J Dwayne
authors.initials: RJ
authors.lastname: Miller
mesh_terms: D055590:Electromagnetic Phenomena; D004735:Energy Transfer; D005452:Fluoresceins / Q000737:chemistry*
chemical_list: D005452:Fluoresceins