Octanuclear Iodoargentate Cluster [Ag8I14]6− Templated by Ln(III)-Terpy Complex Cation: Synthesis, Structure, and Photocatalysis

Abstract

Lanthanide(III) iodoargentate hybrids [Ln(terpy)(DMSO)₅]Ag₄I₇ (Ln = Sm (1), Eu (2), Tb (3); terpy = 2,2′:6,2″-terpyridine; DMSO = dimethyl sulfoxide) are prepared by solvothermal method using lanthanide(III) complex cations formed in situ as templates. All Ln³⁺ ions are coordinated by a terpy and five DMSO ligands, forming [Ln(terpy)(DMSO)₅]³⁺ complex cations with bicapped trigonal prismatic geometry. In 1–3, the four AgI₄ tetrahedra are connected with each other via edge sharing forming an asymmetric structural unit Ag₄I₇. Two Ag₄I₇ units are joined via sharing three I atoms to form the octanuclear isolated anion [Ag₈I₁₄]^6- with a centrosymmetric structure, which represents a new member of 0D iodoargentate clusters. The iodoargentates 1–3 show strong and durable photocurrent responses with steady current densities in the range of 0.95–1.28 μA·cm⁻². They exhibit efficient catalytic activities in the photodegradation of methylene blue with degradation rates of 89.3%, 90.9%, and 96.8%, respectively, after 75 min of light irradiation.