tert-Butyl thiol and pyridine ligand co-protected 50-nuclei clusters: the effect of pyridines on Ag–SR bonds

Abstract

Constructing silver(I)–thiolate clusters from simple building blocks usually involves elusive self-assembly processes and remains a long-standing challenge. In this work, we report 6 silver(I)–thiolate clusters protected by pyridines, namely, [Ag₃(^tBuS)₂(Py)(NO₃)]_n (Py = pyridine) (1), [Ag₁₀(^tBuS)₆(Py)₆(CF₃CO₂)₄]·3Py (2), [Ag₁₂(ⁱPrS)₆(Py)₈(NO₃)₆]·2H₂O (3), Ag₁₂(ⁱPrS)₆(Py)₈(CF₃CO₂)₆ (4), Ag₁₂(ⁱPrS)₆(4-ap)₆(NO₃)₆ (4-ap = 4-aminopyridine) (5), and [Ag₅₀S₁₃(^tBuS)₂₀(Py)₁₂]·4BF₄·4Py·4CH₃OH·2H₂O (6). Single-crystal X-ray crystallography analysis reveals that six clusters are constructed by four types of structural blocks, including the PyAg(^tBuS)₂ monomer, Py₂Ag₂(^tBuS)₂ dimer, Py₃Ag₃(^tBuS)₃ trimer and (4-ap)₆Ag₆(ⁱPrS)₆ hexamer. Notably, cluster 6 consists of a rhombic dodecahedron S@Ag₁₄ kernel with 12 interstitial S²⁻ atoms encapsulated by 8 μ₄-^tBuS⁻ ligands, as well as six unique butterfly-like (Py)₂Ag₆(^tBuS)₂ staple motifs composed of a Py₂Ag₂(^tBuS)₂ dimer and four silver ions. Moreover, it is found that pyridine ligands have important influence on the construction of silver thiolate clusters and their Ag–SR bond lengths.