Heterometallic Pb–Ag iodometallates [Ln(DMF)₈]₂Pb₃Ag₁₀I₂₂ [Ln = Ce(1), Pr(2)] were prepared by the reactions of PbI₂, AgNO₃ and KI in dimethylformamide (DMF) templated by [Ln(DMF)₈]³⁺ complexes formed in situ by stirring LnCl₃ in DMF. The same reactions in the absence of AgNO₃ or PbI₂ afforded iodoplumbate [Pr(DMF)₉]₂[Pr(DMF)₈]Pb₁₁I₃₁ (3), and iodoargentates [Ln(DMF)₈]Ag₆I₉ [Ln = Ce(4), Pr(5)], respectively. Compounds 1 and 2 contain a ternary one-dimensional polymeric [Pb₃Ag₁₀I₂₂]⁶⁻ anion self-assembled from five AgI₄, one PbI₆ and one PbI₄ primary units via edge- and face-sharing. Twelve PbI₆ octahedra are interlinked via sharing of common faces to generate a 1D zigzag [Pb₁₁I₃₁ ⁹⁻]_n chain in 3, which represents a new member of iodoplumbate aggregates. In 4 and 5, three AgI₄ tetrahedra connect through common edges to form the [Ag₆I₁₂]⁶⁻ building block. The [Ag₆I₁₂]⁶⁻ blocks are further interlinked by sharing common edges, resulting in the 1D [Ag₆I₉ ³⁻]_n chain. Optical absorption spectra showed that the synthesized Ag-iodoplumbate and iodoplumbate have potential for being used as semiconductors. Our results show that heterometallic halometallate properties can be tuned by combining structural units with different symmetries, enabling the synthesis of specific functional materials.

Solvothermal reaction of La₂O₃, Sn and Se in dien yields a novel lanthanide selenidostannate [{La(dien)₂}₄(μ₄-Sn₂Se₉)(μ-Sn₂Se₆)]_∞, the first example of the coordination of Sn₂Se₉ and Sn₂Se₆ ligands to hard Lewis acidic lanthanide metals, while the reaction in en yields an ionic compound [La₂(en)₈(μ-Se₂)]Sn₂Se₆ containing a ten-coordinated binuclear lanthanum complex [La₂(en)₈(Se₂)]⁴⁺ with the diselenide Se₂ ^{2 −}group as a bridging ligand.

Two systems, Ln/Sn/Se/en and Ln/Sn/Se/dien, were investigated under solvothermal conditions, and novel lanthanide selenidostannates [{Ce(en)₄}₂(μ-Se₂)]Sn₂Se₆ (1a), [{Ln(en)₃}₂(μ-OH)₂]Sn₂Se₆ (Ln = Pr(1b), Nd(1c), Gd(1d); en = ethylenediamine), [{Ln(dien)₂}₄(μ₄-Sn₂Se₉)(μ-Sn₂Se₆)]_∞ (Ln = Ce(2a), Nd(2b)), and [Hdien][Gd(dien)₂(μ-SnSe₄)] (2c) (dien = diethylenetriamine) were prepared and characterized. Two structural types of lanthanide selenidostannates were obtained across the lanthanide series in both systems. In the Ln/Sn/Se/en system, two types of binuclear lanthanide complex cations [Ce₂(en)₈(μ-Se₂)]⁴⁺ and [{Ln(en)₃}₂(μ-OH)₂]⁴⁺ (Ln = Pr, Nd, Gd) were formed depending on the Ln³⁺ ions. The complex cations are compensated by the [Sn₂Se₆]^{4 −} anions. In the Ln/Sn/Se/dien system, coordination polymer [{Ln(dien)₂}₄(μ₄-Sn₂Se₉)(μ-Sn₂Se₆)]_∞ and ionic complex [Hdien][Gd(dien)₂(μ-SnSe₄)] are obtained along the lanthanide series, among which the μ₄-Sn₂Se₉, μ-Sn₂Se₆ and μ-SnSe₄ ligands to the Ln³⁺ ions were observed. The formation of title complexes shows the effects of lanthanide metal size and amino ligand denticity on the lanthanide selenidostannates. Complexes 1a-2c exhibit semiconducting properties with band gaps between 2.08 and 2.48 eV.