Ambiguities in the proton NMR studies involving Cu(II) ions as paramagnetic relaxation centres

✍ Scribed by Gianni Valensin; Andrea Lepri; Enzo Tiezzi

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 103 KB
• Volume: 79
• Category: Article
• ISSN: 0020-1693
• DOI: 10.1016/s0020-1693(00)95245-9

✦ Synopsis

A Dq value of 1000 cm-' for the Co(I1) ion and 700 cm-' for the Ni(I1) ion, is common for octahedral complexes, the chromophores being MON4Cl for the HPL-DHF ligand and M02N3C1 for the HPL-HIN ligand, respectively.

The parameters of the RES spectra (Table II) suggest anisotropy for the compound Cu,(PL-DHF)-CIZ, the spectrum of Cu(PL-HIN)Cl being approximately isotropic.

The values for g > 2.04 suggest an oblong octahedron.

The IR spectra of the free ligands have the characteristic band of the voxN azomethine stretch at 1625 cm-' for HPL-DHF and at 1665 cm-' for HPL-HIN. The bond formation with the metal ion determined changes of the IR spectra in this region. Both the band position and their intensities varied, confirming that the azomethine group takes part in the bond with the metal ion.