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Title: Vibronic coupling in asymmetric bichromophores: Theory and application to diphenylmethane-d{sub 5}

A theoretical model based on Fulton and Gouterman dimer Hamiltonian [J. Chem. Phys. 35, 1059 (1961)] is used to understand the jet cooled spectra of partly deuterated diphenylmethane (DPM-d{sub 5}), reported in adjoining paper by Zwier and co-workers [“Vibronic coupling in asymmetric bichromophores: Experimental investigation of diphenylmethane-d5,” J. Chem. Phys. 141, 064316 (2014)]. The model is extended to include multiple vibrational modes, vibrational asymmetries between the monomers, and inter-monomer modes. Time dependent density functional theory and equation of motion coupled cluster electronic structure calculations are used to obtain parameters for the model Hamiltonian. The monomer units for DPM-d{sub 5} are toluene and partially deuterated toluene-d{sub 5}. The comparisons of modeled and experimental spectra show that the model captures the vibronic effects on a multitude of observables, including anomalously intense vibrational states, transition dipole moment directions, and localization/delocalization phenomena of both the vibronic and electronic wavefunctions. Following the success of the model, a qualitative picture of vibronic coupling in DPM-d{sub 5} is built using only three active vibrations. This illustrates the ability of the model to not just qualitatively predict but also phenomenologically explain the vibronic effects observed in spectra of complex bichromophores.
Authors:
;  [1]
  1. Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084 (United States)
Publication Date:
OSTI Identifier:
22436545
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPARATIVE EVALUATIONS; COUPLING; DENSITY FUNCTIONAL METHOD; DIMERS; DIPOLE MOMENTS; ELECTRONIC STRUCTURE; EQUATIONS OF MOTION; HAMILTONIANS; MONOMERS; SPECTRA; TIME DEPENDENCE; TOLUENE; VIBRATIONAL STATES; WAVE FUNCTIONS