title: Tuning excited states of bipyridyl platinum(II) chromophores with π-bonded catecholate organometallic ligands: synthesis, structures, TD-DFT calculations, and photophysical properties.
abstract: A series of bipyridyl (bpy) Pt(II) complexes with π-bonded catecholate (cat) [(bpy)Pt(LM)][BF4]n (2-5) (LM = Cp*Rh(cat), n = 2; Cp*Ir(cat), n = 2; Cp*Ru(cat), n = 1; and (C6H6)Ru(cat), n = 2) were prepared and fully characterized. The molecular structures of the four compounds were determined and showed that the solid-state packing is different and dependent on the π-bonded catecholate unit. For instance, while the (bpy)Pt(II) complexes 2 and 3 with rhodium and iridium catecholates did not show any Pt···Pt interactions those with the ruthenium catecholates 4 and 5 showed the presence of Pt···Pt and π-π interactions among individual units and generated one- and two-dimensional supramolecular chains. The photophysical properties of these compounds 2-5 were investigated and showed that all compounds are luminescent at low temperature, in contrast to the well-known parent compound [(C6H4O2)Pt(bpy)] (1), which is weakly luminescent at 77 K. Time-dependent density functional theory studies are advanced to explain this difference in behavior and to highlight the role of the π-bonded catecholate system.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, Université Pierre et Marie Curie and ‡CNRS, Centre National de la Recherche Scientifique, Institut Parisien de Chimie Moléculaire (IPCM) UMR 8232 , 4 place Jussieu, 75252 Paris cedex 05, France.
authors.forename: Jamal
authors.initials: J
authors.lastname: Moussa
authors.forename: Lise-Marie
authors.initials: LM
authors.lastname: Chamoreau
authors.forename: Alessandra
authors.initials: A
authors.lastname: Degli Esposti
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Gullo
authors.forename: Andrea
authors.initials: A
authors.lastname: Barbieri
authors.forename: Hani
authors.initials: H
authors.lastname: Amouri
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D008024:Ligands; D049449:Luminescence; D008958:Models, Molecular; D008968:Molecular Conformation; D009944:Organoplatinum Compounds / Q000737:chemistry*
chemical_list: D008024:Ligands; D009944:Organoplatinum Compounds; D015082:2,2'-Dipyridyl