Reactivities of Interstitial Hydrides in a Cu11 Template: En Route to Bimetallic Clusters.

In sharp contrast to that of surface hydrides, reactivities on interstitial hydrides are difficult to explore. When treated with a metal ion (Cu + , Ag + , and Au + ), the stable Cu(I) dihydride template [Cu 11 H 2 {S 2 P(O i Pr) 2 } 6 (C≡CPh) 3 ] ( H 2 Cu 11 ) generates surprisingly three very different compounds; namely [CuH 2 Cu 11 {S 2 P(O i Pr) 2 } 6 (C≡CPh) 3 ] + ( 1 ), [AgH 2 Cu 14 {S 2 P(O i Pr) 2 } 6 ((C≡CPh) 6 ] + ( 2 ), and [AuCu 11 {S 2 P(O i Pr) 2 } 6 (C≡CPh) 3 Cl] ( 3 ). 1 and 2 are both M(I) species and maintain the same number of hydride ligands as their H 2 Cu 11 precursor. Neutron diffraction revealed the first time a trigonal pyramidal hydride coordination mode in an AgCu 3 environment of 2 . The bimetallic cluster of 3 has no hydride and exhibits a mixed-valent [AuCu 11 ] 10+ metal core, making it a 2-electron superatom. Thus, depending on the nature of M + , trigonal pyramidal hydrides of the H 2 Cu 11 reactant behave differently. In the cases of M = Cu or Ag, they act as regular 2-electron ligands. In the case of M = Au, they behave as electron donors, leading to the formation of a 2-electron superatom, with liberation of H 2 .