Alkyl substituted salicylaldimines for soluble lanthanide complexes

Abstract

2-Hydroxybenzaldehyde-3-hydroxypropylimine (SalH.PrH) and 5-chloro-2-hydroxy benzaldehyde-3-hydroxypropylimine (Cl-Sa!H·PrH) complexes of the tripositive ions of lanthanum, neodymium and ytterbium were prepared and characterised by IR and UV spectroscopy, as well as by magnetic susceptibility studies and metal oxide gravimetry. IR analysis confirmed the tridentate nature of SalH·PrH and Cl-Sall-I·PrH ligand with binding via the azomethine nitrogen atom and the ionised phenolic and unionised alcoholic oxygen atoms. UV studies were limited due to the insoluble nature of the respective complexes in organic solvents. However, the neodymium complex of Cl-SalH·PrH was slightly more soluble than the other complexes in chloroform. Therefore, 1H NMR of the neodymium complex was recorded which revealed that the proton resonances of the aromatic ring were not observed. This indicated that the peaks might be hidden under the other proton resonances of the complexed Cl-SalH·PrH ligand. Metal oxide gravimetry determined the stoichometry of the complexes as Ln(SalH-PrH)] and Ln(Cl-SalH·PrH)] and from these results, the magnetic moments ofthese lanthanide ions in the complexes were determined.