Synthesis and characterization of Pr(III), Nd(III) and Er(III) complexes with 2,6-pyridinedimethanol |
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Authors: | Tatenda Madanhire Eric Hosten Richard Betz |
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Institution: | Department of Chemistry, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa |
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Abstract: | The reactions of Ln(NO3)3?6H2O (Ln=Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H2pydm) in a 1:2 M ratio were investigated, and complexes with the formula Ln(H2pydm)2(NO3)2](NO3) (Ln=Pr or Nd) (1 and 2) and Er(H2pydm)3](NO3)3 (3) were isolated. The compounds contain 10-coordinate Pr(III) and Nd(III) ions that crystallize in the triclinic space group P-1 while the 9-coordinate Er(III) complex crystallizes in the monoclinic system (P21/n). A new lanthanide complex, Pr(H2pydm)3](Cl)3?DMF (4), has been synthesized by reaction of PrCl3?6H2O and H2pydm. The nine-coordinate Pr(III) is bound to three H2pydm ligands. X-ray crystal structures of 1–4 reveal that the ligand coordinates tridentate via the pyridyl nitrogen and the two hydroxyl oxygens. The electronic absorption spectra of 1–4 show 4f–4f transitions. |
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Keywords: | Lanthanide(III) tridentate crystal structure geometry shape analysis |
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