title: Synthesis, Spectroelectrochemical Behavior, and Chiroptical Switching of Tris(β-diketonato) Complexes of Ruthenium(III), Chromium(III), and Cobalt(III).
abstract: Five tris(β-diketonato) complexes of ruthenium(III), chromium(III), and cobalt(III) [Ru(Buacac)3(1), Ru(Oacac)3(2), Cr(Buacac)3(3), Cr(Oacac)3(4), and Co(Buacac)3(5), where Buacac = 3-butylpentane-2,4-dionato and Oacac = 3-octylpentane-2,4-dionato] with a chiral propeller-like structure have been prepared. Ligands and complexes syntheses are presented together with characterization of the compounds by1H and13C NMR spectroscopy, mass spectrometry, IR, UV-vis, electronic circular dichroism (ECD) spectroscopy, electrochemistry studies, and first-principles calculations. The crystal structures of 1 and 5 have also been obtained and analyzed. A comparison of the1H NMR spectra of diamagnetic (ligands and 5) and paramagnetic (1 and 2) species is presented. Optical resolution of the five complexes has been achieved for the first time by supercritical fluid chromatography using a chiral column, giving rise to very high purity grades in all cases. ECD measurements and calculations have led to the assignment of the absolute configuration, Δ or Λ, of each enantiomer for 1-5. Spectroelectrochemical UV-vis and ECD studies have been performed on ruthenium Λ-2 and chromium Λ-4 complexes, revealing their redox-triggered chiroptical switching confirming the noninnocence character of the β-diketonate ligands.
authors.affiliation: CEMES, CNRS UPR 8011, Université de Toulouse , 29 Rue Jeanne Marvig, BP 94347, 31055 Toulouse Cedex 4, France.
authors.forename: Miguel
authors.initials: M
authors.lastname: Cortijo
authors.affiliation: CEMES, CNRS UPR 8011, Université de Toulouse , 29 Rue Jeanne Marvig, BP 94347, 31055 Toulouse Cedex 4, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Viala
authors.affiliation: Sciences Chimiques de Rennes, UMR 6226, CNRS-Université de Rennes 1 , Campus de Beaulieu, 35042 Rennes Cedex, France.
authors.forename: Thibault
authors.initials: T
authors.lastname: Reynaldo
authors.affiliation: Sciences Chimiques de Rennes, UMR 6226, CNRS-Université de Rennes 1 , Campus de Beaulieu, 35042 Rennes Cedex, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Favereau
authors.affiliation: UMR CNRS 5068, LSPCMIB, Université Paul Sabatier , 118 route de Narbonne, 31062 Toulouse Cedex 9, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Fabing
authors.affiliation: Faculty of Chemistry, Jagiellonian University , R. Ingardena 3, 30-060 Krakow, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Srebro-Hooper
authors.affiliation: Department of Chemistry, University at Buffalo, State University of New York , Buffalo, New York 14260, United States.
authors.forename: Jochen
authors.identifier: http://orcid.org/0000-0001-9392-877X
authors.initials: J
authors.lastname: Autschbach
authors.affiliation: CEMES, CNRS UPR 8011, Université de Toulouse , 29 Rue Jeanne Marvig, BP 94347, 31055 Toulouse Cedex 4, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ratel-Ramond
authors.affiliation: Sciences Chimiques de Rennes, UMR 6226, CNRS-Université de Rennes 1 , Campus de Beaulieu, 35042 Rennes Cedex, France.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Crassous
authors.affiliation: CEMES, CNRS UPR 8011, Université de Toulouse , 29 Rue Jeanne Marvig, BP 94347, 31055 Toulouse Cedex 4, France.
authors.forename: Jacques
authors.identifier: http://orcid.org/0000-0003-3741-9529
authors.initials: J
authors.lastname: Bonvoisin