Bis(methimazolyl)borate chemistry of palladium and platinum

The complexes [Pd{κ2-S,S′-H2B(mimMe)2}(η3-C3H4R)] (R = H, Me) have been obtained in high yield from the dichloromethane mediated reaction of the respective [Pd(Cl)(η3-C3H4R)] with K[H2B(mimMe)2]. Attempts to prepare analogous compounds of platinum have led instead to the observation of species consistent with incidences of B–H activation, including the unexpected and facile formation of [PtH(PPh3){κ4-B(mimMe)3}]Cl.

The reactions of palladium allyl dimers with K[H2B(mimMe)2] afford cleanly the respective bis(methimazolyl)borate complexes, while comparable reactions at platinum lead to B–H activation and in the case of [PtCl2(PPh3)2] unexpectedly yield a tris(methimazolyl)borane complex.Figure optionsDownload as PowerPoint slideHighlights
► Two novel dihydrobis(methimazolyl)borate complexes of Pd(II) are synthesised.
► Dihydrobis(methimazolyl)borate undergoes B–H activation at Pt(II) centres.
► Bimolecular recombination affords a tris(methimazolyl)borane complex at Pt.