An Appraisal of the Steric versus Electronic Requirements of Gold(I) Phosphine Substituents in Clusters: The Crystal Structure of [HFe₄(CO)₁₂{AuPEt₃|₂B]

The elucidation of the crystal structure of one isomer of the mixed metal boride [HFe₄(CO)₁₂{AuPEt₃)₂B] illustrates that the geometry of the hexametal atom core and the location of the endo-hydrogen atom depend upon the steric, rather than electronic, requirements of the gold(I) phosphine substituents. Electronic effects, however, are responsible for the AuPR₃ fragment interacting with Fe-B rather than Fe-Fe bonds of the core cluster.