A NiII cubane with a ligand derived from a unique metal ion-promoted, crossed-aldol reaction of acetone with di-2-pyridyl ketone

Nucleophilic attack by the carbanion C¯H2COCH3 at the carbonyl atom of di-2-pyridyl ketone, (py)2CO, in the presence of NiII under basic conditions has yielded the cationic cluster [Ni4{(py)2C(CH2COCH3)(O)}4](ClO4)4 (1). The cluster cation possesses a distorted cubane {Ni4(μ3-OR′)4}4+ core resulting from the η1:η3:η1:η1:μ3 coordination mode of the in situ formed ligand and has a diamagnetic ground state.

A NiII cubane with a diamagnetic ground state has been synthesized in acetone under basic conditions through a crossed-aldol reaction of the initially employed di-2-pyridyl ketone; the in situ formed anionic ligand bridges three metal ions in the complex.Figure optionsDownload as PowerPoint slideHighlights
► The nucleophilic attack of the acetone carbanion at the carbonyl carbon atom of di-2-pyridyl ketone in the presence of metal ions is reported for the first time.
► A Ni4II cubane cluster has been characterized.
► The anion of bis(2-pyridine-2-yl)butane-1-ol-3-one, formed in situ   through a crossed-aldol reaction, participates as ligand in the Ni4II cluster.