title: Synthesis, Structural Characterization, and Chiroptical Studies of Bidentate Salen-Type Lanthanide (III) Complexes.
abstract: The salen-type ligand prepared with (R,R) diphenylethan-1,2-diamine and salicylaldehyde provides stable and inert complexes KLnL2 upon simple reaction with lanthanide halides or pseudohalides LnX3 (Ln = Tb(3+) -Lu(3+) ; X = Cl(-) or TfO(-) ) of its potassium salt. All the complexes were completely characterized through nuclear magnetic resonance (NMR), electronic circular dichroism (ECD) in the UV and some (Er(3+) , Tm(3+) , Yb(3+) ) also with Near-IR ECD (NIR-ECD) and luminescence (Tb(3+) , Tm(3+) ). Careful analysis of the NMR shifts demonstrated that the complexes are isostructural in solution and afforded an accurate geometry. This was further confirmed by means of Density Functional Theory (DFT) optimization of the Lu(3+) complex, and by comparing the ligand-centered experimental and time-dependent TD-DFT computed UV-ECD spectra. As final validation, we used the NIR-ECD spectrum of the Yb(3+) derivative calculated by means of Richardson's equations. The excellent match between calculated and experimental ECD spectra confirm the quality of the NMR structure.
authors.affiliation: Dipartimento di Chimica, Università di Pisa, Pisa, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Berardozzi
authors.affiliation: Dipartimento di Chimica, Università di Pisa, Pisa, Italy.
authors.forename: Gennaro
authors.identifier: http://orcid.org/0000-0002-0869-5076
authors.initials: G
authors.lastname: Pescitelli
authors.affiliation: Dipartimento di Chimica, Università di Pisa, Pisa, Italy.|École Noramle Supérieure de Lyon, Lyon, France.
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Di Pietro
authors.affiliation: Dipartimento di Chimica, Università di Pisa, Pisa, Italy.|CSGI-Dipartimento di Chimica "Ugo Schiff", Università di Firenze, Sesto Fiorentino (FI), Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Resta
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Catania, Catania, Italy.
authors.forename: Francesco P
authors.initials: FP
authors.lastname: Ballistreri
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Catania, Catania, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Pappalardo
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Catania, Catania, Italy.
authors.forename: Gaetano A
authors.initials: GA
authors.lastname: Tomaselli
authors.affiliation: Dipartimento di Chimica, Università di Pisa, Pisa, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Di Bari
mesh_terms: D028581:Lanthanoid Series Elements / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013056:Spectrophotometry, Ultraviolet; D019265:Spectroscopy, Near-Infrared; D013237:Stereoisomerism
chemical_list: D028581:Lanthanoid Series Elements
keywords: TD-DFT calculation; electronic circular dichroism; near-IR circular dichroism; paramagnetic NMR; salen-type ligand