-E-bridged trinuclear triple-decker complexes (E = P, As) containing a triply-bonded Mo unit and their isomerisation.

The reaction of the low-coordinate quadruply-bonded dimolybdenum complex Mo[μ,κ-PhB(-2,6-PrCH)] (1) with Cp*Fe(η-E) (E = P, As) gives two trinuclear species Cp*Fe(μ,η-E)Mo[μ,κ-PhB(-2,6-PrCH)] (E = P (4) and As (5)). 4 undergoes facile isomerisation upon heating to give Cp*FeMo[κ-PhB(-2,6-PrCH)](μ,κ:κ:η-P)[μ,κ:κ:ηκ-PPhB(-2,6-PrCH)] (6), where the FeMoP core motif displays a cubane-like structure.