The first bidentate phosphanylborohydride: Synthesis, structure, and reactivity towards [CpFe(CO)2I]

Deprotonation of the phosphane-borane adduct rac/meso-(HP(BH₃)(Ph)CH₂)₂ (2) with KH provides facile access to the bidentate phosphanylborohydride rac/meso-K₂[(P(BH₃)(Ph)CH₂)₂] (3). Treatment of 3 with two equivalents of [CpFe(CO)₂I] gives the dinuclear complex rac/meso-[(CpFe(CO)₂)₂-μ-(P(BH₃)(Ph)CH₂)₂] (4). Single crystals of the pure diastereomers meso-2, meso-3(thf)₄, and rac-4 have been grown from toluene/pentane, diethyl ether/thf, and benzene/pentane, respectively. The molecular structures of all three compounds have been determined by X-ray crystallography.