Polymeric Iodoargentate Hybrids Incorporating Octakis- or Heptakis-Solvated Lanthanide Complexes: Syntheses, Crystal Structures, and Photocatalysis
Yan Gao, Niannian Chen, Yiming Tian, Jiahua Zhang, Dingxian Jia
Abstract
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.