title: Formazanate boron difluoride dyes: discrepancies between TD-DFT and wavefunction descriptions.
abstract: In this work, we investigate the ground- and excited-state structures as well as the optical properties of a series of five formazanate dyes using state-of-the-art density-based and wavefunction-based methods. The present work is the first to evaluate the properties of formazanate-BF2dyes with wavefunction-correlated schemes. Firstly, we show that CC2 provides more twisted ground-state geometries than DFT while both approaches lead to planar excited-state structures. Secondly, we demonstrate that the differences between the transition energies computed at TD-DFT, CIS(D), SOS-CIS(D), ADC(2), and CC2 levels are large and that the optical spectra also significantly depend on the selected geometries. Indeed, CC2 fluorescence energies computed on TD-DFT structures significantly differ from their full-CC2 counterparts. Thirdly, we discuss the importance of solvent effects evaluated with various continuum models. Fourthly, we provide comparisons with experiment.
authors.affiliation: Laboratoire CEISAM - UMR CNRS 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322, Nantes Cedex 3, France.
authors.forename: Adèle D
authors.initials: AD
authors.lastname: Laurent
authors.affiliation: Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, The Netherlands.
authors.forename: Edwin
authors.initials: E
authors.lastname: Otten
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, 263 Av. du Général Leclerc, 35042, Cedex Rennes, France.
authors.forename: Boris
authors.initials: B
authors.lastname: Le Guennic
authors.affiliation: Laboratoire CEISAM - UMR CNRS 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322, Nantes Cedex 3, France. denis.Jacquemin@univ-nantes.fr.|Institut Universitaire de France, 103, Blvd. Saint-Michel, 75005, Paris Cedex 05, France. denis.Jacquemin@univ-nantes.fr.
authors.forename: Denis
authors.initials: D
authors.lastname: Jacquemin
keywords: BODIPY; CC2; Emission; Fluoroborates; Optical spectra; TD-DFT