Grid-double-helicate interconversion.

An interconversion between a binuclear Cu(I) double helicate and a tetranuclear Cu(II) grid is reported. The passage from the Cu(I) double helicate to the Cu(II) grid occurs through oxidation of Cu(I) into Cu(II) or through displacement of Cu(I) by Cu(II). The conversion of the Cu(II) grid into the Cu(I) double helicate occurs through treatment of the grid with triflic acid, reduction of Cu(II) with ascorbic acid, and neutralization with triethylamine. During the studies, in order to ascertain the structure of Cu(I) complexes, a heteroleptic binuclear Cu(I) double helicate was generated.