Synthesis of a lanthanum(II) terphenolate complex and EPR spectroscopic comparison with its thiolate and amide analogs.

Potassium graphite reduction of La(OAriPr6)2I [AriPr6 = C6H3-2,6-(C6H2-2,4,6-iPr3)2] forms the first example of a monomeric, homoleptic bis(phenolate) complex of lanthanum(II), La(OAriPr6)2, and demonstrates that the terphenolate ligand can stabilize a 5d1 lanthanide(II) ion. Structural, spectroscopic, and DFT analyses of the terphenolate complex are presented to evaluate the effects of the donor atom on its structure and hyperfine coupling in comparison with the sulfur and nitrogen donor atom analogs, La(SAriPr6)2 and La[N(H)AriPr6]2.