MIXED-LIGAND LANTHANIDE COMPLEXES .7. COMPLEXES OF 1,10-PHENANTHROLINE AND THIOCYANATE

The thiocyanatoaqua-tris(1,10-phenanthroline) lanthanide(III)thiocyana tes, [Ln(phen)(3)(H2O)(SCN)](SCN)(2) (where Ln = La-III and all trival ent lanthanides, except Pm and Lu) have been synthesized and character ized. The molar conductances, IR spectra and thermograms show the pres ence of both coordinated and non-coordinated thiocyanate. The complexe s are eight-coordinate. Very large chemical shifts are observed in the NMR spectra of paramagnetic complexes. The interelectronic and covale ncy parameters calculated for the complexes show the covalent nature o f bonding between the metal and the ligand. The oscillator strengths o f the f-f transitions are calculated and discussed. The complexes appe ar to accept one solvent molecule (DMSO) and become nine-coordinate in solution.