Dy 3+ White Light Emission Can Be Finely Controlled by Tuning the First Coordination Sphere of Ga 3+ /Dy 3+ Metallacrown Complexes

Eliseeva, Svetlana V.  (ORCID:0000000217688513); Salerno, Elvin V.; Lopez Bermudez, Beatriz A.; Petoud, Stéphane  (ORCID:0000000346594505); Pecoraro, Vincent L.  (ORCID:0000000215405735)

doi:10.1021/jacs.0c07198

The molecular tetravalent oxidation state for praseodymium is observed in solution via oxidation of the anionic trivalent precursor [K][Pr 3+ (NP(1,2-bis- t Bu-diamidoethane)(NEt 2 )) 4 ] (1-Pr(NP*)) with AgI at −35 °C. The Pr 4+ complex is characterized in solution via cyclic voltammetry, UV-vis-NIR electronic absorption spectroscopy, and EPR spectroscopy. Electrochemical analyses of [K][Ln 3+ (NP(1,2-bis- t Bu-diamidoethane)(NEt 2 )) 4 ] (Ln = Nd and Dy) by cyclic voltammetry are reported and, in conjunction with theoretical modeling of electronic structure and oxidation potential, are indicative of principal ligand oxidations in contrast to the metal-centered oxidation observed for 1-Pr(NP*). The identification of a tetravalent praseodymium complex in in situ UV-vis and EPR experiments is further validated by theoretical modeling of the redox chemistry and the UV-vis spectrum. The latter study was performed by extended multistate pair-density functional theory (XMS-PDFT) and implicates a multiconfigurational ground state for the tetravalent praseodymium complex.

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