Metallaboratranes Derived from a Triphosphanyl–Borane: Intrinsic C 3 Symmetry Supported by a Z‐Type Ligand

Symmetry from within : Coordination of a triphosphanyl–borane ligand to gold(I) and platinum(0) affords metallaboratranes exhibiting C 3 symmetry both in solution and in the solid state. Such a helical geometry is supported by axial M→B dative interactions and results from the envelope conformations of the PCCBM metallacycles.