Tungsten-tungsten multiple-bond functionalities supported by a polyoxo surface modeled by calix(4)arene

Research was conducted to examine the reduction chemistry of the parent compound (cis-Cl2W(p-Bu(super t)-calix(4)-(O)4)) to generate reactive fragments such as neutral 2-W(IV)- and monoanionic d3-W(III)-tetraoxo species. The stepwise reductive coupling resulted to the formation of metal-metal-bonded metalla-calix(4)arene dimers containing double, triple and quadruple W-W bonds. To demonstrate the electronic configuration of the metal-metal functionalities when sandwiched by two calix(4)arene tetraanions, extended Huckel calculations were carried out.