Syntheses, crystal structures and near-infrared luminescent properties of holmium (Ho) and praseodymium (Pr) ternary complexes

Magnetic and Luminescence Properties of 8-Coordinate Holmium(III) Complexes Containing 4,4,4-Trifluoro-1-Phenyl- and 1-(Naphthalen-2-yl)-1,3-Butanedionates

“…The band located at 1179 nm accounts for the 5 I 6 → 5 I 8 transition; the very weak band at 1474 nm corresponds to the 5 F 5 → 5 I 6 transition [ 80 ]. The results obtained here agree with other Ho(III) coordination compounds, where the study of the sensitization of Ho 3+ luminescence by the energy transfer from chromophore ligands has been performed [ 81 , 82 , 83 , 84 , 85 ].…”

NIR-luminescence from ternary lanthanide [HoIII, PrIII and TmIII] complexes with 1-(2-naphthyl)-4,4,4-trifluoro-1,3-butanedionate

“…The 5 I 7 -5 I 8 transition ( 41900 nm) was not observed, since it exceeds the measurement range of our detector. With respect to the optimum energy difference favors efficient ligand-to-ion energy transfer, it is believed that 5 S 2 , 5 F 4 and 5 F 5 levels are the main acceptor levels and the excited electrons on the 5 F 5 and 5 I 6 levels, to an extent, come from the relaxation of the upper levels followed by the transitions to the lower levels to give the NIR emissions of the Ho 3 þ ion [30]. Basically, the first triplet state (T 1 ) of Htfnd [31], which is 19,700 cm À 1 , can certainly sensitize the levels of Ho 3 þ below T 1 via energy transfer.…”

Multifunctionality of the [C2mim][Ln(fod)4] series (Ln = Nd–Tm except Pm): magnetic, luminescence and thermochemical studies

“…As expected, the first triplet state (T1) of the fod ligand can sensitize the levels of Ho 3+ below T1 of the fod ligand via energy transfer, populating the 5 F 5 and 5 I 6 levels. 33…”