Synthesis and characterization of organotin triflate clusters

A variety of organotin triflate clusters are obtained by treating dialkyltin oxide with triflic acid (TfOH) in different ratios. When R2SnO is exposed to 0.5 equivalents of TfOH, 3-hydroxy-1-triflato distannoxanes (1) are formed which have a novel sheet-like structure in the solid state. Treatment of R2SnO with 2/3 or one equivalent of TfOH affords a trinuclear cluster 3 or cationic dimers 2. The stoichiometry of the novel trinuclear cluster can be confirmed by various chemical reactions as well as elemental analysis. On the basis of 119Sn-NMR study, the equilibrium has been revealed between 2 and 3. The use of two equivalents of TfOH in the reaction with R2SnO offers a convenient route for R2Sn(OTf)2 (4).