title: Vibrational circular dichroism and chiroptical properties of chiral Ir(iii) luminescent complexes.
abstract: The octahedral ionic Ir(iii) complex with a dual stereogenic centre of general formula Δ,Λ-(R,S)-[(ppy)2Ir(Me-Campy)]X, where ppy = 2-phenylpyridine and Me-Campy = 2-methyl-5,6,7,8-tetrahydroquinolin-8-amine, and the complex Λ-(R,S)-[(ppy)2Ir(H-Campy)]X, where ppy = 2-phenylpyridine, H-Campy = 8-amino-5,6,7,8-tetrahydroquinolines and X(-) = Cl(-) as a counterion in both cases, have been characterized by vibrational circular dichroism (VCD), which turns out to be efficacious in diastereomeric discrimination. Moreover, the single crystal X-ray structure of the complex Δ-(R)-[(ppy)2Ir(Me-Campy)]Cl is reported here. Density functional theory (DFT) calculations allow us to conclude that the most important doublet feature in the VCD spectra is associated with a clear vibrational exciton structure located on the two dissymmetrically disposed phenylpyridine ligands. The features in the VCD spectra associated with the (R) or (S)-central chirality configuration are identified and commented on. DFT calculations provide also the interpretation of electronic circular dichroism (ECD) spectra. Finally, circularly polarized luminescence (CPL) spectra are presented as an additional chiroptical characterization of these luminescent iridium complexes.
authors.affiliation: Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy. sergio.abbate@unibs.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mazzeo
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Milano, Via Golgi 19, 20133 Milano, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Fusè
authors.affiliation: Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy. sergio.abbate@unibs.it and CNISM Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Via della Vasca Navale, 84, 00146 Roma, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Longhi
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Milano, Via Golgi 19, 20133 Milano, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Rimoldi
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Milano, Via Golgi 19, 20133 Milano, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Cesarotti
authors.affiliation: MAT_INLAB (Laboratorio di Materiali Molecolari Inorganici) (Unità della Calabria, Dipartimento di Chimica e Tecnologie Chimiche) University of Calabria, I-87030 Arcavacata di Rende, CS, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Crispini
authors.affiliation: Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy. sergio.abbate@unibs.it and CNISM Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Via della Vasca Navale, 84, 00146 Roma, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Abbate