A Series of Lanthanide Selenidogermanates: The First Coexistence of Three Types of Selenidogermanate Units in the Same Architecture.

A series of lanthanide selenidogermanates, (Hpeha)[Ln(μ-OH)(tepa)Cl]{Ln(μ-OH)(tepa)Cl}[GeSe]Cl [Ln = Y (1a) and Er (1b); peha = pentaethylenexamine, tepa = tetraethylenepentamine], [Sm(μ-OH)(tepa)(μ-GeSe)] (2), [Ho(μ-OH)(tepa)(μ-GeSe)] (3), and [Ce(tepa)(μ-GeSe)(μ-GeSe)(μ-GeSe)] (4), were made under solvothermal conditions. Compounds 1a and 1b contain a protonated Hpeha ion, the complex cation [Ln(μ-OH)(tepa)Cl], a [GeSe] anion, free Cl ions, and a {Ln(μ-OH)(tepa)Cl} cation constructed by two unsaturated [Ln(μ-OH)(tepa)Cl] groups connecting via the trans terminal Se atoms of the [GeSe] anion, which provides the first example of an organic decorated lanthanide selenidogermanate cation. Both compounds 2 and 3 contain one-dimensional chains [Ln(μ-OH)(tepa)(μ-GeSe)] constructed by a combination of unsaturated complex cations [Ln(μ-OH)(tepa)] and [GeSe] anions, but their stacking patterns of neutral chains are different. Compound 4 contains one-dimensional chain [Ce(tepa)(μ-GeSe)(μ-GeSe)(μ-GeSe)], where three different selenidogermanate units acting as bridging ligands connect unsaturated [Ce(tepa)] ions. Compound 4 represents the first example of the coexistence of three different selenidogermanate anions in the same architecture. Their optical properties are studied, and the magnetic properties of compounds 1b and 2-4 are also investigated.