Luminescent Ce(III) Complexes as Stoichiometric and Catalytic Photoreductants for Halogen Atom Abstraction Reactions

Haolin Yin; Patrick J Carroll; Jessica M Anna; Eric J Schelter

doi:10.1021/jacs.5b05411

Luminescent Ce(III) Complexes as Stoichiometric and Catalytic Photoreductants for Halogen Atom Abstraction Reactions

J Am Chem Soc. 2015 Jul 29;137(29):9234-7. doi: 10.1021/jacs.5b05411. Epub 2015 Jul 20.

Authors

Haolin Yin¹, Patrick J Carroll¹, Jessica M Anna¹, Eric J Schelter¹

Affiliation

¹ P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34 Street, Philadelphia, Pennsylvania 19104, United States.

PMID: 26151154
DOI: 10.1021/jacs.5b05411

Abstract

Luminescent Ce(III) complexes, Ce[N(SiMe3)2]3 (1) and [(Me3Si)2NC(RN)2]Ce[N(SiMe3)2]2 (R = (i)Pr, 1-(i)Pr; R = Cy, 1-Cy), with C(3v) and C(2v) solution symmetries display absorptive 4f → 5d electronic transitions in the visible region. Emission bands are observed at 553, 518, and 523 nm for 1, 1-(i)Pr, and 1-Cy with lifetimes of 24, 67, and 61 ns, respectively. Time-dependent density functional theory (TD-DFT) studies on 1 and 1-(i)Pr revealed the (2)A1 excited states corresponded to singly occupied 5d(z(2)) orbitals. The strongly reducing metalloradical character of 1, 1-(i)Pr, and 1-Cy in their (2)A1 excited states afforded photochemical halogen atom abstraction reactions from sp(3) and sp(2) C-X (X = Cl, Br, I) bonds for the first time with a lanthanide cation. The dehalogenation reactions could be turned over with catalytic amounts of photosensitizers by coupling salt metathesis and reduction to the photopromoted atom abstraction reactions.