Synthesis, Structure, and Optical Properties of Lanthanum(III), Cerium(III), Praseodymium(III), and Nickel(II) Heterometallic Complexes with Glycine

摘要

New cluster complexes of lanthanides(III) and nickel(II) [Ln{Ni(Gly)(2)}(6)](3+)[Ln(NO3)(6)](3-) have been synthesized, where Ln = La (I), Ce (II), and Pr (III); and Gly is glycinate. The structures of compounds I-III are determined by X-ray diffraction. The icosahedral cavity in the complex cation, where the lanthanide ion resides, has a fixed size independent of the nature of the central Ln(III) ion. In the complex anion, on the contrary, the Ln-O distances naturally decrease from La(III) to Pr(III). The optical properties of cationanion complexes I-III are studied. Based on the assignment in the electronic absorption spectra of the complexes, it is shown that the absorption bands are caused by d-d electronic transitions.