title: Structure and photophysics of near-infrared emissive ytterbium(III) monoporphyrinate acetate complexes having neutral bidentate ligands.
abstract: Substitution reactions between [Yb(TPP)(OOCCH3)(CH3OH)2] (1) and neutral bidentate ligands NN led to the formation of monoporphyrinate ytterbium(III) complexes [Yb(TPP)(OOCCH3)(NN)] (TPP = 5,10,15,20-tetraphenylporphyrinate anion; NN = 4-methyl-1,10-phenanthroline (2), 1,10-phenanthroline (3), 4,7-dimethyl-1,10-phenanthroline (4), 5,6-epoxy-5,6-dihydroxy-1,10-phenanthroline (5) and 2,2'-dipyridylamine (6)). Single-crystal X-ray diffraction analysis revealed that ytterbium(III) ions in 1 and 6 were seven-coordinate with OOCCH3- in monodentate coordination, whereas those in 2, 3, 4 and 5 were eight-coordinate with OOCCH3- in bidentate coordination. The visible emission (650 and 720 nm) from the porphyrin and near-infrared (NIR) emission (980 and 1003 nm) from ytterbium(III) ion were observed for all complexes. The eight-coordinate complexes exhibited stronger NIR emission and longer lifetimes in toluene solution than the seven-coordinate complexes. The NIR emission of complexes with decreased lifetimes was also observed when they were blended into organic polymer PMMA.
authors.affiliation: Center for Advanced Photovoltaics, Department of Electrical Engineering, South Dakota State University, Brookings, SD 57007, USA. hongshan.he@sdstate.edu
authors.forename: Hongshan
authors.initials: H
authors.lastname: He
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Sykes
authors.forename: P Stanley
authors.initials: PS
authors.lastname: May
authors.forename: Guishan
authors.initials: G
authors.lastname: He
mesh_terms: D018360:Crystallography, X-Ray; D008024:Ligands; D008968:Molecular Conformation; D011166:Porphyrins / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D008024:Ligands; D011166:Porphyrins; D015018:Ytterbium