Synthesis, structure and near-infrared luminescence of neutral 3d-4f bi-metallic monoporphyrinate complexes

The interaction of cationic lanthanide complexes [Ln(porp)(H2O)3]+(Ln= Er or Yb; porp = porphyrinate) with sodium (cyclopentadienyl)tris(diethylphosphito)cobaltate (NaLOEt) gives the neutral 3d-4f bi-metallic porphyrinate complexes, [(LOEt)Ln(porp)]. X-Ray structural analyses reveal that these complexes are seven-coordinate with the three oxygen atoms of the O3-tripodal ligand, LOEt, coordinated to the lanthanide metal behaving as a 6-electron donor. Photophysical measurements show that the porphyrinate ligand behaves as a sensitizer by absorbing visible light to excite the Ln(III) metal ions, producing near-infrared emission.