Novel Holmium (Ho) and Praseodymium (Pr) ternary complexes with fluorinated-ligand and 4,5-diazafluoren-9-one

Four ternary complexes Ln1 and Ln2 (Ln=Ho and Pr) were synthesized, with 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)hexane-1,3-dione and 4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-pentadecafluoro-1-(naphthalen-2-yl)decane-1,3-dione served as main sensitizers, respectively. Their elemental analyses, Fourier Transform Infrared spectra, and luminescent properties were investigated. The complexes all show the characteristic near-infrared luminescence of corresponding Ln(3+) ions, via an antenna effect. Furthermore, the influence of ligands structure on the luminescence behavior of complexes is discussed and it is believed that the fluorinated alkyl chains of ligands affect the energy transfer in complexes. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.