Simultaneous coordination of a ketone by two cadmium(II) ions and conversion to its gem-diolate(− 1) form

► The first Cd(II) complex containing the ketone form of di-2-pyridyl ketone is reported. ► The bridging carbonyl group is transformed into its gem-diolate(− 1) form. ► A cubane Cd(II) cluster has been prepared and characterized. ► The Cd(II)/di-2-pyridyl ketone complex exhibits blue-green photoluminescence.