Synthesis and X‐Ray Crystallographic Characterisation of Frustum‐Shaped Ligated [Cu 18 H 16 (DPPE) 6 ] 2+ and [Cu 16 H 14 (DPPA) 6 ] 2+ Nanoclusters and Studies on Their H 2 Evolution Reactions

We report new structural motifs for Cu nanoclusters that conceptually represent seed crystals for large face‐centred cubic (FCC) crystal growth. Kinetically controlled syntheses, high resolution mass spectrometry experiments for determination of the dication formulae and crystallographic characterisation were carried out for [Cu 18 H 16 (DPPE) 6 ][BF 4 ][Cl] (DPPE=bis(diphenylphosphino)ethane) and [Cu 16 H 14 (DPPA) 6 ][(BF 4 ) 2 ] (DPPA=bis(diphenylphosphino)amine) polyhydrido nanoclusters, which feature the unprecedented bifrustum and frustum metal‐core architecture in metal nanoclusters. The Cu 18 nanocluster contains two Cu 9 frustum cupolae and the Cu 16 nanocluster has one Cu 9 frustum cupola and a Cu 7 distorted hexagonal‐shape base. Gas‐phase experiments revealed that both Cu 18 H 16 and Cu 16 H 14 cores can spontaneously release H 2 upon removal of one bisphosphine capping ligand.