title: 1-Methyl-3-hydroxy-pyridin-2-one complexes of near infra-red emitting lanthanides: efficient sensitization of Yb(III) and Nd(III) in aqueous solution.
abstract: The synthesis, X-ray structure, solution stability, and photophysical properties of several trivalent lanthanide complexes of Yb(III) and Nd(III) using both tetradentate and octadentate ligand design strategies and incorporating the 1-methyl-3-hydroxy-pyridin-2-one (Me-3,2-HOPO) chelate group are reported. Both the Yb(III) and Nd(III) complexes have emission bands in the Near Infra-Red (NIR) region, and this luminescence is retained in aqueous solution (Phi(tot)(Yb) approximately 0.09-0.22%).Furthermore, the complexes demonstrate very high stability (pYb approximately 18.8-21.9) in aqueous solution, making them good candidates for further development as probes for NIR imaging. Analysis of the low temperature (77 K) photophysical measurements for a model Gd(III) complex were used to gain an insight into the electronic structure, and were found to agree well with corresponding time-dependent density functional theory (TD-DFT) calculations at the B3LYP/6-311G++(d,p) level of theory for a simplified model monovalent sodium complex.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
authors.forename: Evan G
authors.initials: EG
authors.lastname: Moore
authors.forename: Jide
authors.initials: J
authors.lastname: Xu
authors.forename: Sheel C
authors.initials: SC
authors.lastname: Dodani
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Jocher
authors.forename: Anthony
authors.initials: A
authors.lastname: D'Aléo
authors.forename: Michael
authors.initials: M
authors.lastname: Seitz
authors.forename: Kenneth N
authors.initials: KN
authors.lastname: Raymond
mesh_terms: D018360:Crystallography, X-Ray; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009354:Neodymium / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011728:Pyridones / Q000737:chemistry*; D012996:Solutions; D014867:Water / Q000737:chemistry; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D028581:Lanthanoid Series Elements; D009942:Organometallic Compounds; D011728:Pyridones; D012996:Solutions; D014867:Water; C048216:1-methyl-3-hydroxypyridine-2-one; D009354:Neodymium; D015018:Ytterbium