A Polyoxochromate Templated 56-Nuclei Silver Nanocluster

Abstract

Most of polyoxometallates (POMs) templated silver nanoclusters recorded so far are polyoxomolybdates and polyoxotungstates; however, as congeneric polyoxochromates, they are rarely observed in silver nanoclusters. Herein, a high-nuclearity polyoxochromate, (Cr^III₄Cr^VI₈O₃₆)^12-, is uncovered in a novel silver nanocluster (SD/Ag56a) as an anion template. The mixed-valent (Cr^III₄Cr^VI₈O₃₆)^12- consists of four edge-sharing Cr^IIIO₆ octahedra and eight Cr^VIO₄ tetrahedra, which are fused together by sharing one or two vertexes. The (Cr^III₄Cr^VI₈O₃₆)^12- is the by far highest nuclearity polyoxochromate and is trapped by outer Ag₅₆ bracelet-like shell coprotected by quaternary ligands including ⁱPrS^-, NapCOO^- (2-naphthalenecarboxylate), CF₃COO^-, and CH₃CN. The antiferromagnetic property and solution behavior of SD/Ag56a are discussed in detail.