The addition of a yellow ethanolic solution of di-2-pyridyl ketone to a blu
e-green aqueous solution of copper(II) bromide produces an exothermic react
ion and a brilliant purple solution. Brilliant purple single crystals were
obtained from the solution by solvent evaporation and were subjected to a c
rystal structure determination. The structure of the isolated gem-diol comp
ound stabilized by a transition metal contains two di(2-pyridyl)methanediol
ligands bonded to the central copper atom in a distorted octahedral arrang
ement providing four nitrogen atoms at relatively short bond distances and
two oxygen atoms at longer bond distances. In the solid state, both oxygen
atoms on each of the gem-diol ligands are protonated. (C) 2000 Elsevier Sci
ence Ltd All rights reserved.