Polymeric Iodoargentate Hybrids Incorporating Octakis- or Heptakis-Solvated Lanthanide Complexes: Syntheses, Crystal Structures, and Photocatalysis.

New iodoargentate hybrids containing lanthanide complexes, [La(DMA)8]Ag9I12·2H2O (1) and [Ln(DMA)7]2Ag16I22 (Ln = Pr (2), Sm(3); DMA = N,N-dimethylacetamide), were prepared by diffusion methods using DMA-solvated lanthanide complexes as structure-directing agents. The octakis-solvated La3+ cation leads to formation of the 1-D nonanuclear [Ag9I12]n3n- polymeric anion constructed by AgI4 tetrahedral units through edge sharing, while the heptakis-solvated Ln3+ (Ln = Pr, Sm) cation affords the new 1-D hexadecanuclear [Ag16I22]n6n- polymeric anion built up from AgI4 units by both corner and edge sharing. Compounds 1-3 possess band gaps of 2.58, 2.77, and 2.74 eV, respectively, and show steady photocurrents in the range 14.2-18.0 μA under Xe light irradiation. They are photocatalytic active in the degradation of organic pollutants of crystal violet (CV) and rhodamine B (RhB) in water at room temperature. 2 and 3 perform higher photocatalytic activities than 1 in the CV degradation, which is attributed to the different photocurrent intensities. Photocatalytic mechanism investigations on compounds 2 and 3 show that h+ hole and ·O2- radical play major roles in the CV degradation, respectively.