Isolation of mixed valence charge-neutral Ag12, and dicationic Ag10 nano-clusters stabilized by carbene-phosphaalkenides

Abstract

Cyclic alkyl(amino) carbene (cAAC)-supported phosphaalkenides (cAACP)⁻ have been employed as ligands for the isolation of two atomically precise mixed valence paramagnetic Ag^I/0₁₂Cl₃, and Ag^I/0₁₀, nano-clusters [(Me₂-cAACP)₆Ag₁₂Cl₃] (2), and [(Me₂-cAACP)₆Ag₁₀](NTf₂)₂ (4). 2 and 4 have been structurally characterized by single-crystal X-ray diffraction revealing the presence of three Ag⁰ atoms, nine Ag^I ions (2); and two Ag⁰ atoms, eight Ag^I ions (4), respectively. The clustering inorganic unit Ag₁₂Cl₃ in 2 has been found to be surrounded by six mono-anionic μ₃-cAACP moieties having 3-bar symmetry. 2 and 4 have been studied by cyclic voltammetry, UV-vis, ESI-MS, XPS, EPR spectroscopy, and DFT calculations.