We investigate the role of axial ligands on the near-IR-optical and paramagnetic NMR spectra of the complex [YbL](+3) where L is the stereodefined enantiopure chiral macrocycle (L = hexaazapentacyclo[184.108.40.206(12,24).0(4,9).0(19,24)]- dotriaconta-1(31),2,10,12,14,16(32),17,25,27,29-decaene). The conformation in solution of the lanthanide complex is characterized by analyzing the pseudocontact H-1 NMR shifts and is consistent with X-ray data of single crystal of analogue systems. The macrocycle is confined within a thin equatorial disk, leaving the cation open to at least two axial sites, on the opposite hemispheres. We recorded, assigned, and analyzed the H-1 NMR spectra of several species upon changing the anion in solution, calculating the magnetic susceptibility anisotropy tensor for each. Near-IR circular dichroism is used to investigate the solution equilibria involving the competing ligands and to derive a spectroscopic series for Yb.
|Autori interni:||DI BARI, LORENZO|
|Autori:||J. LISOWSKI; S. RIPOLI; DI BARI L|
|Titolo:||Axial ligand exchange in chiral macrocyclic Ytterbium(III) complexes|
|Anno del prodotto:||2004|
|Digital Object Identifier (DOI):||10.1021/ic0353918|
|Appare nelle tipologie:||1.1 Articolo in rivista|