Coordination Chemistry of Diiodine and Implications for the Oxidation Capacity of the Synergistic Ag+/X-2 (X=Cl, Br, I) System

摘要

The synergistic Ag+/X-2 system (X= Cl, Br, I) is a very strong, but ill-defined oxidant-more powerful than X-2 or Ag+ alone. Intermediates for its action may include [Ag-m-(X-2)(n)](m+) complexes. Here, we report on an unexpectedly variable coordination chemistry of diiodine towards this direction: (A) Ag-I-2-Ag(A), [Ag-2(I-2)(4)](2+)(A(-))(2) and [Ag-2(I-2)(6)](2+)(A(-))(2)center dot(I-2)(x approximate to 0.65) form by reaction of Ag(A) (A= Al(ORF)(4); R-F = C(CF3)(3)) with diiodine (single crystal/powder XRD, Raman spectra and quantum-mechanical calculations). The molecular (A) Ag-I-2-Ag(A) is ideally set up to act as a 2 e(-) oxidant with stoichiometric formation of 2 AgI and 2 A(-). Preliminary reactivity tests proved this (A) Ag-I-2-Ag(A) starting material to oxidize n-C5H12, C3H8, CH2Cl2, P-4 or S-8 at room temperature. A rough estimate of its electron affinity places it amongst very strong oxidizers like MF6 (M= 4d metals). This suggests that (A) Ag-I-2-Ag(A) will serve as an easily in bulk accessible, well-defined, and very potent oxidant with multiple applications.